diff --git a/changes/4192.feature.md b/changes/4192.feature.md
new file mode 100644
index 0000000000..757aa13895
--- /dev/null
+++ b/changes/4192.feature.md
@@ -0,0 +1,25 @@
+Added core support for URL pipelines (https://github.com/jbms/url-pipeline):
+`|`-chained URLs that address zarr data through nested storage layers, e.g.
+`s3://bucket/data.zip|zip:|zarr3:`. This PR adds the parser, the single-method
+`zarr.abc.url_pipeline.URLPipelineAdapter` interface, and the
+`zarr.url_adapters` entry-point group through which third-party packages
+(e.g. Icechunk) register adapters for their own schemes. Adapters for a scheme
+are loaded lazily and individually. Builtin adapters (`zip:`,
+`zarr2:`/`zarr3:`) follow in separate pull requests.
+
+Behavior notes:
+
+- The `|` character is now reserved as the pipeline delimiter in every string
+ store specification, and no percent-escape is decoded; pass a `pathlib.Path`
+ to address a local file whose name contains `|`. URLs without a `|` (and
+ without a registered root adapter scheme) are handled exactly as before —
+ registered adapters cannot intercept zarr's native `file:`/`memory:`
+ routing, and fsspec chained URLs (`zip::s3://...`) keep flowing to fsspec.
+- Inside a pipeline, `memory:` and `file:` roots follow the URL pipeline
+ spec's semantics (spelling equivalences; `file:` must be absolute, with at
+ most a `localhost` authority).
+- Mode `"a"` (open-or-create, the `zarr.open` default) on a *read-only* store
+ now serves the "open" half instead of raising upfront, for all stores;
+ unambiguous write modes (`"w"`, `"w-"`, `"r+"`) still raise.
+- For root-adapter URLs (e.g. `gh://org/repo`), `storage_options` are handed
+ to the adapter and are not validated as used by `make_store`.
diff --git a/docs/api/zarr/abc/index.md b/docs/api/zarr/abc/index.md
index 7e15cb2a51..d155f60a5a 100644
--- a/docs/api/zarr/abc/index.md
+++ b/docs/api/zarr/abc/index.md
@@ -11,3 +11,4 @@ Abstract base classes for extending Zarr-Python.
- **[zarr.abc.metadata](./metadata.md)** - Creating metadata classes compatible with the Zarr API
- **[zarr.abc.numcodec](./numcodec.md)** - Protocols and classes for modeling codec interface used by numcodecs
- **[zarr.abc.store](./store.md)** - ABC for implementing Zarr stores and managing getting and setting bytes in a store
+- **[zarr.abc.url_pipeline](./url_pipeline.md)** - ABC for implementing [URL pipeline](https://github.com/jbms/url-pipeline) adapters
diff --git a/docs/api/zarr/abc/url_pipeline.md b/docs/api/zarr/abc/url_pipeline.md
new file mode 100644
index 0000000000..2606d4d5d4
--- /dev/null
+++ b/docs/api/zarr/abc/url_pipeline.md
@@ -0,0 +1,5 @@
+---
+title: url_pipeline
+---
+
+::: zarr.abc.url_pipeline
diff --git a/docs/user-guide/storage.md b/docs/user-guide/storage.md
index a34e2e2874..0b86bef2b0 100644
--- a/docs/user-guide/storage.md
+++ b/docs/user-guide/storage.md
@@ -103,6 +103,31 @@ print(group)
- a [`Store`][zarr.abc.store.Store] or [`StorePath`][zarr.storage.StorePath] -
see explicit store creation below.
+## URL Pipelines {#user-guide-url-pipelines}
+
+Zarr supports [URL pipelines](https://github.com/jbms/url-pipeline): `|`-chained URLs
+that address zarr data through nested storage layers, read left to right. The first
+sub-URL locates a resource with a conventional URL; each subsequent sub-URL names an
+*adapter* that reinterprets everything to its left (e.g.
+`s3://bucket/data.zip|zip:|zarr3:`). Adapters are provided by packages through the
+`zarr.url_adapters` entry-point group — see
+[`zarr.abc.url_pipeline`][zarr.abc.url_pipeline] for the adapter interface. Builtin
+adapters (`zip:`, `zarr2:`/`zarr3:`) are under development and will expand this
+section. URLs without a `|` (and without a registered root scheme) are handled
+exactly as before.
+
+`storage_options` passed to `zarr.open` apply to the *root* sub-URL (e.g. fsspec
+options for `s3://...`); adapters may consume adapter-specific, namespaced keys.
+Non-dict forms of `storage_options` are reserved for future per-segment
+configuration.
+
+The `|` character is reserved as the pipeline delimiter in every string store
+specification, and no percent-escape is decoded: to address a local file whose
+*name* contains `|` (or `#`), pass a `pathlib.Path` instead of a string.
+Registered adapters cannot intercept zarr's native `file:` and `memory:` root
+schemes, and fsspec's chained-URL syntax (`zip::s3://...`) keeps flowing to
+fsspec.
+
## Explicit Store Creation
In some cases, it may be helpful to create a store instance directly. Zarr-Python offers
diff --git a/mkdocs.yml b/mkdocs.yml
index 4d06701a87..58b5d3344a 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -43,6 +43,7 @@ nav:
- ' zarr.abc.metadata': api/zarr/abc/metadata.md
- ' zarr.abc.numcodec': api/zarr/abc/numcodec.md
- ' zarr.abc.store': api/zarr/abc/store.md
+ - ' zarr.abc.url_pipeline': api/zarr/abc/url_pipeline.md
- ' zarr.api':
- api/zarr/api/index.md
- ' zarr.api.asynchronous': api/zarr/api/asynchronous.md
diff --git a/src/zarr/abc/url_pipeline.py b/src/zarr/abc/url_pipeline.py
new file mode 100644
index 0000000000..0e0363bcf6
--- /dev/null
+++ b/src/zarr/abc/url_pipeline.py
@@ -0,0 +1,256 @@
+"""
+Abstract base class and data model for URL pipeline adapters.
+
+A URL pipeline is a `|`-separated chain of sub-URLs, read outer-to-inner,
+as specified by https://github.com/jbms/url-pipeline. The first sub-URL (the
+*root*) locates a resource using a conventional URL, and each subsequent
+sub-URL names an *adapter* that reinterprets everything to its left:
+
+ s3://bucket/data.zip|zip:path/inside|zarr3:
+
+Third-party packages provide adapters by subclassing
+[`URLPipelineAdapter`][zarr.abc.url_pipeline.URLPipelineAdapter] and
+registering the class under the `zarr.url_adapters` entry-point group,
+using the URL scheme as the entry-point name.
+"""
+
+from __future__ import annotations
+
+import enum
+from abc import ABC, abstractmethod
+from dataclasses import dataclass
+from typing import TYPE_CHECKING, Any
+
+from zarr.errors import URLPipelineError
+
+if TYPE_CHECKING:
+ from zarr.abc.store import Store
+ from zarr.core.common import AccessModeLiteral, ZarrFormat
+
+__all__ = [
+ "AdapterResolution",
+ "PipelineContext",
+ "PipelineSegment",
+ "URLPipelineAdapter",
+]
+
+
+class _Unset(enum.Enum):
+ token = 0
+
+
+_UNSET = _Unset.token
+
+
+@dataclass(frozen=True)
+class PipelineSegment:
+ """
+ One `|`-delimited sub-URL of a URL pipeline.
+
+ Attributes
+ ----------
+ scheme : str
+ The lowercased URL scheme. Empty string only for a schemeless root
+ (a bare local path), which is treated as opaque text.
+ body : str
+ The text after `scheme:` and before any `?`. Interpretation is
+ scheme-defined; it is **not** URL-normalized, so case-significant
+ content (e.g. icechunk snapshot IDs) is preserved.
+ query : str | None
+ The raw query string after `?`, or None. Interpretation is
+ scheme-defined.
+ raw : str
+ The exact original sub-URL text, preserved for lossless
+ reconstruction of the pipeline.
+ """
+
+ scheme: str
+ body: str
+ query: str | None
+ raw: str
+
+ def __str__(self) -> str:
+ return self.raw
+
+
+@dataclass(frozen=True)
+class AdapterResolution:
+ """
+ The result of resolving a URL pipeline (or a prefix of one).
+
+ Attributes
+ ----------
+ store : Store
+ The resolved store.
+ path : str
+ Residual path *within* the store that the pipeline addresses
+ (e.g. `"path/to/node"` for `...|icechunk://tag.v1/path/to/node`).
+ Empty string when the pipeline addresses the store root.
+ zarr_format : ZarrFormat | None
+ Zarr format selected by a format segment (`zarr2:`/`zarr3:`),
+ or None if unspecified. A wrapper adapter that re-wraps a preceding
+ resolution must carry every field it does not change forward —
+ prefer `dataclasses.replace(preceding, store=..., path=...)` over
+ reconstructing, so fields added later are never silently dropped.
+ """
+
+ store: Store
+ path: str = ""
+ zarr_format: ZarrFormat | None = None
+
+
+@dataclass(frozen=True)
+class PipelineContext:
+ """
+ Context handed to a [`URLPipelineAdapter`][zarr.abc.url_pipeline.URLPipelineAdapter]
+ describing the pipeline to the left of its segment.
+
+ Attributes
+ ----------
+ preceding : tuple[PipelineSegment, ...]
+ The parsed sub-URLs to the left of the adapter's segment, outer to
+ inner. Empty when the adapter's segment is the pipeline root.
+ mode : AccessModeLiteral | None
+ The access mode requested by the caller (e.g. `zarr.open(mode=...)`),
+ or None when unspecified. Adapters for read-only resources should
+ raise for unambiguous write modes (`"w"`, `"w-"`, `"r+"`) and
+ open read-only otherwise. `"a"` (the `zarr.open` default) means
+ open-or-create: read-only adapters serve the "open" half, and any
+ subsequent write fails at the store level.
+ storage_options : dict[str, Any] | None
+ Options passed by the caller. By convention these configure the
+ *root* sub-URL (e.g. fsspec options); adapters may consume
+ adapter-specific keys, and should namespace them (e.g.
+ `myscheme_credentials`) to avoid collisions with other segments'
+ backends. An adapter that consumes keys should strip them before
+ resolving the rest of the pipeline, by passing the reduced mapping
+ to [`resolve_preceding`][zarr.abc.url_pipeline.PipelineContext.resolve_preceding].
+ Non-dict forms of the caller-facing `storage_options` argument are
+ reserved for future per-segment configuration (one mapping per
+ pipeline segment); this attribute will remain a single mapping —
+ the one addressed to this adapter's segment.
+ """
+
+ preceding: tuple[PipelineSegment, ...]
+ mode: AccessModeLiteral | None
+ storage_options: dict[str, Any] | None
+
+ @property
+ def read_only(self) -> bool:
+ """
+ True when the caller requires a read-only store (`mode == "r"`).
+
+ Adapters must construct their store read-only when this is set
+ (the resolver enforces it afterwards); when it is False, they may
+ construct a writable store if the underlying resource supports
+ writing.
+ """
+ return self.mode == "r"
+
+ @property
+ def preceding_url(self) -> str:
+ """
+ The pipeline to the left of this segment, reconstructed exactly.
+
+ An adapter that consumes this string instead of calling
+ [`resolve_preceding`][zarr.abc.url_pipeline.PipelineContext.resolve_preceding]
+ takes ownership of the *entire* preceding pipeline: it must
+ validate every preceding segment itself and raise
+ [`URLPipelineError`][zarr.errors.URLPipelineError] for segments it
+ does not understand, so that no segment is ever silently ignored.
+ """
+ return "|".join(segment.raw for segment in self.preceding)
+
+ async def resolve_preceding(
+ self,
+ *,
+ mode: AccessModeLiteral | _Unset | None = _UNSET,
+ storage_options: dict[str, Any] | _Unset | None = _UNSET,
+ ) -> AdapterResolution:
+ """
+ Resolve the preceding pipeline into a store.
+
+ This is the entry point for *wrapper* adapters (e.g. `zip:`) that
+ operate on the resource produced by the segments to their left. It
+ composes with any preceding adapters, because each segment is
+ resolved by its own adapter. Adapters backed by their own I/O
+ machinery (e.g. `icechunk:`) may instead consume
+ [`preceding_url`][zarr.abc.url_pipeline.PipelineContext.preceding_url]
+ and never materialize the intermediate store — subject to the
+ ownership contract documented there.
+
+ Parameters
+ ----------
+ mode : AccessModeLiteral | None, optional
+ Override the mode used to resolve the preceding pipeline.
+ Wrapper adapters that only read the preceding resource should
+ pass `mode="r"` so the root is opened read-only and without
+ create-on-open side effects, regardless of the caller's mode.
+ When omitted, the caller's mode is used.
+ storage_options : dict | None, optional
+ Override the options forwarded to the preceding pipeline. An
+ adapter that consumed adapter-specific keys should pass the
+ remaining mapping here (or None when nothing remains), so the
+ root store never sees keys that were not addressed to it.
+ When omitted, the caller's options are forwarded unchanged.
+ """
+ from zarr.storage._url_pipeline import _resolve
+
+ if not self.preceding:
+ raise URLPipelineError(
+ "this adapter segment is at the pipeline root; "
+ "there is no preceding sub-URL to resolve"
+ )
+ return await _resolve(
+ self.preceding,
+ mode=self.mode if isinstance(mode, _Unset) else mode,
+ storage_options=(
+ self.storage_options if isinstance(storage_options, _Unset) else storage_options
+ ),
+ )
+
+
+class URLPipelineAdapter(ABC):
+ """
+ Handler for one URL pipeline scheme.
+
+ Subclasses implement a single classmethod,
+ [`open_pipeline_segment`][zarr.abc.url_pipeline.URLPipelineAdapter.open_pipeline_segment],
+ and are registered under the `zarr.url_adapters` entry-point group with
+ the URL scheme as the entry-point name:
+
+ [project.entry-points."zarr.url_adapters"]
+ mypackage.myscheme = "mypackage.zarr_adapter:MyAdapter"
+
+ Nonstandard schemes should be vendor-prefixed (`vendor.scheme`) per the
+ URL pipeline specification.
+
+ An adapter is used in two positions:
+
+ - as an *adapter segment*: `s3://bucket/repo|icechunk://tag.v1` — the
+ context carries the preceding sub-URLs;
+ - as a *root scheme*: `gh://org/repo` — `context.preceding` is empty.
+ """
+
+ @classmethod
+ @abstractmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ """
+ Resolve `segment` (in the context of the pipeline to its left)
+ into a store and an optional residual path within that store.
+
+ The returned store must already be open and must honor
+ `context.read_only` (the resolver additionally enforces it by
+ downgrading — or rejecting — a writable store when the caller
+ required read-only).
+
+ This coroutine runs on zarr's internal I/O event loop. It must not
+ block (do I/O through async APIs or a thread executor) and must not
+ call zarr's synchronous API (`zarr.open`, `Group.open`, or anything
+ else that uses `zarr.core.sync.sync`) — doing so raises
+ `SyncError`. To open the preceding pipeline, use
+ [`resolve_preceding`][zarr.abc.url_pipeline.PipelineContext.resolve_preceding].
+ """
+ ...
diff --git a/src/zarr/api/asynchronous.py b/src/zarr/api/asynchronous.py
index 3bdc254ea5..2ae05bef6f 100644
--- a/src/zarr/api/asynchronous.py
+++ b/src/zarr/api/asynchronous.py
@@ -108,6 +108,24 @@ def _infer_overwrite(mode: AccessModeLiteral) -> bool:
return mode in _OVERWRITE_MODES
+def _merge_pipeline_zarr_format(
+ store_path: StorePath, zarr_format: ZarrFormat | None
+) -> ZarrFormat | None:
+ """
+ Combine a zarr format selected by a URL pipeline segment (`zarr2:` /
+ `zarr3:`) with the caller's `zarr_format` argument. Explicitly
+ conflicting selections raise.
+ """
+ if store_path.zarr_format is None:
+ return zarr_format
+ if zarr_format is not None and zarr_format != store_path.zarr_format:
+ raise ValueError(
+ f"zarr_format={zarr_format} conflicts with the 'zarr{store_path.zarr_format}:' "
+ "segment of the URL pipeline"
+ )
+ return store_path.zarr_format
+
+
def _warn_unimplemented_kwargs(kwargs: dict[str, Any]) -> None:
"""
Emit a "not yet implemented" warning for each provided keyword argument that is not None.
@@ -389,6 +407,7 @@ async def open(
else:
mode = "a"
store_path = await make_store_path(store, mode=mode, path=path, storage_options=storage_options)
+ zarr_format = _merge_pipeline_zarr_format(store_path, zarr_format)
# TODO: the mode check below seems wrong!
if "shape" not in kwargs and mode in {"a", "r", "r+", "w"}:
@@ -494,13 +513,14 @@ async def save_array(
**kwargs
Passed through to [`create`][zarr.api.asynchronous.create], e.g., compressor.
"""
- if zarr_format is None:
- zarr_format = _default_zarr_format()
if not isinstance(arr, NDArrayLike):
raise TypeError("arr argument must be numpy or other NDArrayLike array")
mode = kwargs.pop("mode", "a")
store_path = await make_store_path(store, path=path, mode=mode, storage_options=storage_options)
+ zarr_format = _merge_pipeline_zarr_format(store_path, zarr_format)
+ if zarr_format is None:
+ zarr_format = _default_zarr_format()
if np.isscalar(arr):
arr = np.array(arr)
shape = arr.shape
@@ -550,6 +570,7 @@ async def save_group(
"""
store_path = await make_store_path(store, path=path, mode="w", storage_options=storage_options)
+ zarr_format = _merge_pipeline_zarr_format(store_path, zarr_format)
if zarr_format is None:
zarr_format = _default_zarr_format()
@@ -762,12 +783,12 @@ async def create_group(
The new group.
"""
- if zarr_format is None:
- zarr_format = _default_zarr_format()
-
mode: Literal["a"] = "a"
store_path = await make_store_path(store, path=path, mode=mode, storage_options=storage_options)
+ zarr_format = _merge_pipeline_zarr_format(store_path, zarr_format)
+ if zarr_format is None:
+ zarr_format = _default_zarr_format()
return await AsyncGroup.from_store(
store=store_path,
@@ -857,6 +878,7 @@ async def open_group(
)
store_path = await make_store_path(store, mode=mode, storage_options=storage_options, path=path)
+ zarr_format = _merge_pipeline_zarr_format(store_path, zarr_format)
if attributes is None:
attributes = {}
@@ -1041,9 +1063,6 @@ async def create(
z : array
The array.
"""
- if zarr_format is None:
- zarr_format = _default_zarr_format()
-
_warn_unimplemented_kwargs(
{
"synchronizer": synchronizer,
@@ -1063,6 +1082,9 @@ async def create(
if mode is None:
mode = "a"
store_path = await make_store_path(store, path=path, mode=mode, storage_options=storage_options)
+ zarr_format = _merge_pipeline_zarr_format(store_path, zarr_format)
+ if zarr_format is None:
+ zarr_format = _default_zarr_format()
config_parsed = parse_array_config(config)
@@ -1262,6 +1284,7 @@ async def open_array(
mode = kwargs.pop("mode", None)
store_path = await make_store_path(store, path=path, mode=mode, storage_options=storage_options)
+ zarr_format = _merge_pipeline_zarr_format(store_path, zarr_format)
if "write_empty_chunks" in kwargs:
_warn_write_empty_chunks_kwarg()
diff --git a/src/zarr/errors.py b/src/zarr/errors.py
index 781bebe534..de04a5bdaa 100644
--- a/src/zarr/errors.py
+++ b/src/zarr/errors.py
@@ -12,6 +12,7 @@
"MetadataValidationError",
"NegativeStepError",
"NodeTypeValidationError",
+ "URLPipelineError",
"UnstableSpecificationWarning",
"VindexInvalidSelectionError",
"ZarrDeprecationWarning",
@@ -100,6 +101,12 @@ class UnknownCodecError(BaseZarrError):
"""
+class URLPipelineError(BaseZarrError):
+ """
+ Raised when a URL pipeline cannot be parsed or resolved.
+ """
+
+
class NodeTypeValidationError(MetadataValidationError):
"""
Specialized exception when the node_type of the metadata document is incorrect.
diff --git a/src/zarr/registry.py b/src/zarr/registry.py
index c2c0eb2921..53875c015c 100644
--- a/src/zarr/registry.py
+++ b/src/zarr/registry.py
@@ -1,5 +1,6 @@
from __future__ import annotations
+import threading
import warnings
from collections import defaultdict
from importlib.metadata import entry_points as get_entry_points
@@ -7,7 +8,7 @@
from zarr.core.config import BadConfigError, config
from zarr.core.dtype import data_type_registry
-from zarr.errors import ZarrUserWarning
+from zarr.errors import URLPipelineError, ZarrUserWarning
if TYPE_CHECKING:
from importlib.metadata import EntryPoint
@@ -21,6 +22,7 @@
CodecPipeline,
)
from zarr.abc.numcodec import Numcodec
+ from zarr.abc.url_pipeline import URLPipelineAdapter
from zarr.core.buffer import Buffer, NDBuffer
from zarr.core.chunk_key_encodings import ChunkKeyEncoding
from zarr.core.common import JSON
@@ -32,11 +34,14 @@
"get_codec_class",
"get_ndbuffer_class",
"get_pipeline_class",
+ "get_url_adapter",
+ "list_url_adapter_schemes",
"register_buffer",
"register_chunk_key_encoding",
"register_codec",
"register_ndbuffer",
"register_pipeline",
+ "register_url_adapter",
]
@@ -62,6 +67,7 @@ def register(self, cls: type[T], qualname: str | None = None) -> None:
_buffer_registry: Registry[Buffer] = Registry()
_ndbuffer_registry: Registry[NDBuffer] = Registry()
_chunk_key_encoding_registry: Registry[ChunkKeyEncoding] = Registry()
+_url_adapter_registry: Registry[URLPipelineAdapter] = Registry()
"""
The registry module is responsible for managing implementations of codecs,
@@ -108,6 +114,8 @@ def _collect_entrypoints() -> list[Registry[Any]]:
entry_points.select(group="zarr", name="chunk_key_encoding")
)
+ _url_adapter_registry.lazy_load_list.extend(entry_points.select(group="zarr.url_adapters"))
+
_pipeline_registry.lazy_load_list.extend(entry_points.select(group="zarr.codec_pipeline"))
_pipeline_registry.lazy_load_list.extend(
entry_points.select(group="zarr", name="codec_pipeline")
@@ -124,6 +132,7 @@ def _collect_entrypoints() -> list[Registry[Any]]:
_buffer_registry,
_ndbuffer_registry,
_chunk_key_encoding_registry,
+ _url_adapter_registry,
]
@@ -303,6 +312,72 @@ def get_chunk_key_encoding_class(key: str) -> type[ChunkKeyEncoding]:
return _chunk_key_encoding_registry[key]
+def register_url_adapter(scheme: str, cls: type[URLPipelineAdapter]) -> None:
+ """
+ Register a [`URLPipelineAdapter`][zarr.abc.url_pipeline.URLPipelineAdapter]
+ class for a URL scheme.
+
+ Registering a scheme that already has an adapter replaces it and emits a
+ [`ZarrUserWarning`][zarr.errors.ZarrUserWarning].
+ """
+ key = scheme.lower()
+ previous = _url_adapter_registry.get(key)
+ if previous is not None and previous is not cls:
+ warnings.warn(
+ f"URL pipeline adapter for scheme {scheme!r} is being replaced: "
+ f"{fully_qualified_name(previous)} -> {fully_qualified_name(cls)}",
+ category=ZarrUserWarning,
+ stacklevel=2,
+ )
+ _url_adapter_registry.register(cls, key)
+
+
+def list_url_adapter_schemes() -> set[str]:
+ """
+ The set of URL schemes with a registered URL pipeline adapter.
+
+ Includes adapters advertised via not-yet-loaded `zarr.url_adapters`
+ entry points; consulting this does not import any adapter code.
+ Schemes are case-insensitive and reported lowercased.
+ """
+ return set(_url_adapter_registry) | {
+ e.name.lower() for e in _url_adapter_registry.lazy_load_list
+ }
+
+
+_url_adapter_lock = threading.Lock()
+
+
+def get_url_adapter(scheme: str) -> type[URLPipelineAdapter]:
+ """
+ Get the URL pipeline adapter class registered for `scheme`.
+
+ Loads pending `zarr.url_adapters` entry points for this scheme only, so
+ resolving one scheme never imports other providers' packages.
+ """
+ key = scheme.lower()
+ # The lock keeps concurrent first-time resolutions of different schemes
+ # from clobbering each other's rebuild of the pending entry-point list.
+ with _url_adapter_lock:
+ if key not in _url_adapter_registry:
+ remaining = []
+ for entry_point in _url_adapter_registry.lazy_load_list:
+ if entry_point.name.lower() == key:
+ _url_adapter_registry.register(entry_point.load(), qualname=key)
+ else:
+ remaining.append(entry_point)
+ _url_adapter_registry.lazy_load_list[:] = remaining
+ try:
+ return _url_adapter_registry[key]
+ except KeyError:
+ registered = sorted(list_url_adapter_schemes())
+ raise URLPipelineError(
+ f"no URL pipeline adapter is registered for scheme {scheme!r}. "
+ f"Registered schemes: {registered}. Adapters are provided by "
+ "packages via the 'zarr.url_adapters' entry-point group."
+ ) from None
+
+
_collect_entrypoints()
diff --git a/src/zarr/storage/__init__.py b/src/zarr/storage/__init__.py
index f1bd1724af..edc01f1a5b 100644
--- a/src/zarr/storage/__init__.py
+++ b/src/zarr/storage/__init__.py
@@ -10,6 +10,7 @@
from zarr.storage._logging import LoggingStore
from zarr.storage._memory import GpuMemoryStore, ManagedMemoryStore, MemoryStore
from zarr.storage._obstore import ObjectStore
+from zarr.storage._url_pipeline import parse_pipeline, resolve_pipeline
from zarr.storage._wrapper import WrapperStore
from zarr.storage._zip import ZipStore
@@ -25,6 +26,8 @@
"StorePath",
"WrapperStore",
"ZipStore",
+ "parse_pipeline",
+ "resolve_pipeline",
]
diff --git a/src/zarr/storage/_common.py b/src/zarr/storage/_common.py
index 72b5fc8a40..7bf294bfd3 100644
--- a/src/zarr/storage/_common.py
+++ b/src/zarr/storage/_common.py
@@ -21,9 +21,15 @@
AccessModeLiteral,
ZarrFormat,
)
-from zarr.errors import ContainsArrayAndGroupError, ContainsArrayError, ContainsGroupError
+from zarr.errors import (
+ ContainsArrayAndGroupError,
+ ContainsArrayError,
+ ContainsGroupError,
+ URLPipelineError,
+)
from zarr.storage._local import LocalStore
from zarr.storage._memory import ManagedMemoryStore, MemoryStore
+from zarr.storage._url_pipeline import is_url_pipeline, resolve_pipeline
from zarr.storage._utils import UPath, _join_paths, normalize_path, parse_store_url
_has_fsspec = importlib.util.find_spec("fsspec")
@@ -47,14 +53,22 @@ class StorePath:
The store to use.
path : str
The path within the store.
+
+ Attributes
+ ----------
+ zarr_format : ZarrFormat | None
+ Zarr format selected by a `zarr2:`/`zarr3:` URL pipeline segment,
+ or None. Not part of the StorePath's identity (ignored by `__eq__`).
"""
store: Store
path: str
+ zarr_format: ZarrFormat | None
def __init__(self, store: Store, path: str = "") -> None:
self.store = store
self.path = normalize_path(path)
+ self.zarr_format = None
@property
def read_only(self) -> bool:
@@ -72,7 +86,10 @@ async def open(cls, store: Store, path: str, mode: AccessModeLiteral | None = No
Open StorePath based on the provided mode.
* If the mode is None, return an opened version of the store with no changes.
- * If the mode is 'r+', 'w-', 'w', or 'a' and the store is read-only, raise a ValueError.
+ * If the mode is 'r+', 'w-', or 'w' and the store is read-only, raise a ValueError.
+ * If the mode is 'a' (open-or-create) and the store is read-only, serve the
+ "open" half: the StorePath is opened read-only, and any subsequent write
+ fails at the store level.
* If the mode is 'r' and the store is not read-only, return a copy of the store with read_only set to True.
* If the mode is 'w-' and the store is not read-only and the StorePath contains keys, raise a FileExistsError.
* If the mode is 'w' and the store is not read-only, delete all keys nested within the StorePath.
@@ -95,7 +112,7 @@ async def open(cls, store: Store, path: str, mode: AccessModeLiteral | None = No
FileExistsError
If the mode is 'w-' and the store path already exists.
ValueError
- If the mode is not "r" and the store is read-only, or
+ If the mode is "r+", "w-", or "w" and the store is read-only, or
"""
# fastpath if mode is None
@@ -106,8 +123,9 @@ async def open(cls, store: Store, path: str, mode: AccessModeLiteral | None = No
raise ValueError(f"Invalid mode: {mode}, expected one of {ANY_ACCESS_MODE}")
if store.read_only:
- # Don't allow write operations on a read-only store
- if mode != "r":
+ # mode "a" (open-or-create) on a read-only store means open-only;
+ # unambiguous write modes are rejected outright.
+ if mode not in ("r", "a"):
raise ValueError(
f"Store is read-only but mode is {mode!r}. Create a writable store or use 'r' mode."
)
@@ -273,7 +291,9 @@ def delete_sync(self) -> None:
def __truediv__(self, other: str) -> StorePath:
"""Combine this store path with another path"""
- return self.__class__(self.store, _join_paths([self.path, other]))
+ result = self.__class__(self.store, _join_paths([self.path, other]))
+ result.zarr_format = self.zarr_format
+ return result
def __str__(self) -> str:
return _join_paths([str(self.store), self.path])
@@ -348,6 +368,16 @@ async def make_store(
"""
from zarr.storage._fsspec import FsspecStore # circular import
+ if isinstance(store_like, str) and is_url_pipeline(store_like):
+ result = await resolve_pipeline(store_like, mode=mode, storage_options=storage_options)
+ if normalize_path(result.path):
+ result.store.close()
+ raise URLPipelineError(
+ f"the URL pipeline {store_like!r} resolves to a path inside a store; "
+ "use zarr.open() or make_store_path() instead of make_store()"
+ )
+ return result.store
+
# Parse URL early so we can reuse the result for both validation and routing
parsed = parse_store_url(store_like) if isinstance(store_like, str) else None
@@ -464,6 +494,13 @@ async def make_store_path(
"""
path_normalized = normalize_path(path)
+ if isinstance(store_like, str) and is_url_pipeline(store_like):
+ result = await resolve_pipeline(store_like, mode=mode, storage_options=storage_options)
+ combined_path = _join_paths([normalize_path(result.path), path_normalized])
+ store_path = await StorePath.open(result.store, path=combined_path, mode=mode)
+ store_path.zarr_format = result.zarr_format
+ return store_path
+
if isinstance(store_like, StorePath):
# Already a StorePath
if storage_options:
diff --git a/src/zarr/storage/_url_pipeline.py b/src/zarr/storage/_url_pipeline.py
new file mode 100644
index 0000000000..0161bdee6a
--- /dev/null
+++ b/src/zarr/storage/_url_pipeline.py
@@ -0,0 +1,311 @@
+"""
+Parsing and resolution of URL pipelines (https://github.com/jbms/url-pipeline).
+
+Importing this module is cheap and has no side effects: third-party adapters
+(registered through the `zarr.url_adapters` entry-point group) are loaded
+only when a pipeline URL naming their scheme is actually resolved.
+
+The `|` character is reserved as the pipeline delimiter in every string
+store specification: a string containing `|` is always routed through the
+pipeline machinery, and no percent-escape is decoded. To address a local
+file whose *name* contains `|` (or `#`), pass a `pathlib.Path` instead of a
+string.
+
+As a zarr-python extension to the specification (which requires the root
+sub-URL of an absolute pipeline to carry a scheme), the root sub-URL may be
+a schemeless local filesystem path, e.g. `data/example.zip|zip:`. Schemeless
+roots are treated as opaque text — no query or fragment splitting is applied
+to them. Such pipelines are not portable to other URL pipeline
+implementations; portable pipelines should spell the root as a `file:` URL.
+"""
+
+from __future__ import annotations
+
+import dataclasses
+import re
+from typing import TYPE_CHECKING, Any
+
+from zarr.abc.url_pipeline import (
+ AdapterResolution,
+ PipelineContext,
+ PipelineSegment,
+)
+from zarr.errors import URLPipelineError
+from zarr.registry import get_url_adapter, list_url_adapter_schemes
+from zarr.storage._memory import ManagedMemoryStore
+from zarr.storage._utils import parse_store_url
+
+if TYPE_CHECKING:
+ from zarr.abc.store import Store
+ from zarr.core.common import AccessModeLiteral
+
+__all__ = ["is_url_pipeline", "parse_pipeline", "resolve_pipeline"]
+
+# Adapter scheme per RFC 3986 plus "." to permit vendor-prefixed
+# nonstandard schemes (e.g. "earthmover.myscheme").
+_SCHEME_RE = re.compile(r"^[a-zA-Z][a-zA-Z0-9+.\-]*$")
+
+# Root scheme at the very start of the sub-URL. The negative lookahead
+# excludes fsspec's chained-URL syntax (``zip::file://...``), which is not a
+# URL pipeline and keeps flowing through the fsspec machinery.
+_ROOT_SCHEME_RE = re.compile(r"([a-zA-Z][a-zA-Z0-9+.\-]*):(?!:)")
+
+# Schemes zarr resolves natively at the pipeline root. These are never
+# dispatched to a registered root adapter, so an installed package cannot
+# intercept zarr's own local-path and in-memory routing.
+_NATIVE_ROOT_SCHEMES = frozenset({"file", "memory"})
+
+# An absolute Windows drive path (C:\... or C:/...), which counts as an
+# absolute path in a `file:` pipeline root.
+_WINDOWS_DRIVE_RE = re.compile(r"[A-Za-z]:[/\\]")
+
+
+def _root_scheme(root_sub_url: str) -> str:
+ """
+ Detect the scheme of the root sub-URL, or `""` for an opaque root.
+
+ Scheme extraction happens on the raw string (so nothing `urlparse`
+ would strip or reject — whitespace, exotic authorities — can desync the
+ detected scheme from the body). Single-letter candidates are delegated
+ to `parse_store_url`, which knows Windows drive letters are not schemes.
+ """
+ match = _ROOT_SCHEME_RE.match(root_sub_url)
+ if match is None:
+ return ""
+ scheme = match.group(1)
+ if len(scheme) == 1:
+ try:
+ return parse_store_url(root_sub_url).scheme.lower()
+ except ValueError:
+ return scheme.lower()
+ return scheme.lower()
+
+
+def _split_query(sub_url: str) -> tuple[str, str | None]:
+ """Split a sub-URL on the first `?`. Fragments are not supported."""
+ if "#" in sub_url:
+ raise URLPipelineError(
+ f"URL pipeline sub-URLs do not support fragments: {sub_url!r}. "
+ "Percent-encode '#' as '%23' if it is part of the path."
+ )
+ body, sep, query = sub_url.partition("?")
+ return body, query if sep else None
+
+
+def parse_pipeline(url: str) -> tuple[PipelineSegment, ...]:
+ """
+ Parse a URL pipeline into its `|`-delimited segments.
+
+ The first segment is the *root* sub-URL; its scheme is detected with the
+ same rules as ordinary store URLs (Windows drive letters are not
+ schemes). Subsequent segments are *adapter* sub-URLs of the form
+ `scheme:body` where the trailing colon is optional when the body is
+ empty (`zip` is equivalent to `zip:`).
+
+ A schemeless root (a bare local path) is accepted as a zarr-python
+ extension to the specification and treated as opaque text: no query or
+ fragment splitting applies, since `?` and `#` are ordinary filename
+ characters there. See the module docstring.
+
+ Segment text is preserved verbatim (no case or percent-encoding
+ normalization) except that schemes are lowercased.
+ """
+ parts = url.split("|")
+ if any(not part for part in parts):
+ raise URLPipelineError(f"URL pipeline contains an empty sub-URL: {url!r}")
+
+ segments: list[PipelineSegment] = []
+ for index, part in enumerate(parts):
+ if index == 0:
+ scheme = _root_scheme(part)
+ if not scheme:
+ # opaque root (bare local path, fsspec chained URL, ...)
+ segments.append(PipelineSegment(scheme="", body=part, query=None, raw=part))
+ continue
+ body_and_scheme, query = _split_query(part)
+ body = body_and_scheme[len(scheme) + 1 :]
+ segments.append(PipelineSegment(scheme=scheme, body=body, query=query, raw=part))
+ else:
+ body_and_scheme, query = _split_query(part)
+ scheme, _, body = body_and_scheme.partition(":")
+ scheme = scheme.lower()
+ if not _SCHEME_RE.match(scheme):
+ raise URLPipelineError(
+ f"invalid adapter scheme {scheme!r} in pipeline segment {part!r}"
+ )
+ segments.append(PipelineSegment(scheme=scheme, body=body, query=query, raw=part))
+ return tuple(segments)
+
+
+def _root_routes_to_adapter(scheme: str) -> bool:
+ """
+ Whether a root sub-URL with this scheme is dispatched to a registered
+ root adapter. Schemes zarr resolves natively (`file:`, `memory:`) and
+ opaque roots are excluded; the registry check inspects entry-point
+ names only — no adapter code is imported here.
+ """
+ return (
+ bool(scheme) and scheme not in _NATIVE_ROOT_SCHEMES and scheme in list_url_adapter_schemes()
+ )
+
+
+def is_url_pipeline(url: str) -> bool:
+ """
+ Whether `url` should be routed through the URL pipeline machinery.
+
+ True when the URL contains a `|` separator, or when its scheme has a
+ registered URL pipeline adapter (a *root adapter* such as `gh:`).
+ fsspec chained URLs (`zip::file://...`) and zarr's native `file:` /
+ `memory:` schemes are never routed to a root adapter.
+ """
+ if "|" in url:
+ return True
+ return _root_routes_to_adapter(_root_scheme(url))
+
+
+async def resolve_pipeline(
+ url: str,
+ *,
+ mode: AccessModeLiteral | None = None,
+ storage_options: dict[str, Any] | None = None,
+) -> AdapterResolution:
+ """
+ Resolve a URL pipeline into a store and a residual path.
+
+ Parameters
+ ----------
+ url : str
+ A URL pipeline, e.g. `"s3://bucket/data.zip|zip:|zarr3:"`.
+ mode : AccessModeLiteral | None
+ The caller's access mode. `"r"` requires a read-only store; the
+ resolver enforces this on whatever the final adapter returns.
+ storage_options : dict | None
+ Options forwarded to the root sub-URL's store (and visible to
+ adapters via the context). Non-dict forms are reserved for future
+ per-segment configuration (one mapping per pipeline segment).
+ """
+ segments = parse_pipeline(url)
+ if len(segments) == 1 and not _root_routes_to_adapter(segments[0].scheme):
+ raise URLPipelineError(
+ f"{url!r} is not a URL pipeline: it has no '|' separator and no "
+ f"URL pipeline adapter is registered for scheme {segments[0].scheme!r}"
+ )
+ return await _resolve(segments, mode=mode, storage_options=storage_options)
+
+
+async def _resolve(
+ segments: tuple[PipelineSegment, ...],
+ *,
+ mode: AccessModeLiteral | None,
+ storage_options: dict[str, Any] | None,
+) -> AdapterResolution:
+ if len(segments) == 1 and not _root_routes_to_adapter(segments[0].scheme):
+ return AdapterResolution(
+ store=await _resolve_root(segments[0], mode=mode, storage_options=storage_options)
+ )
+
+ *preceding, last = segments
+ try:
+ adapter_cls = get_url_adapter(last.scheme)
+ except URLPipelineError as exc:
+ raise URLPipelineError(
+ f"{exc} Note: '|' is reserved as the URL pipeline delimiter; to "
+ "address a local file whose name contains '|', pass a "
+ "pathlib.Path instead of a string."
+ ) from None
+
+ context = PipelineContext(
+ preceding=tuple(preceding),
+ mode=mode,
+ storage_options=storage_options,
+ )
+ resolution = await adapter_cls.open_pipeline_segment(last, context)
+ if mode == "r" and not resolution.store.read_only:
+ # The caller required read-only; enforce it rather than trusting
+ # the adapter to have honored context.read_only.
+ try:
+ read_only_store = resolution.store.with_read_only(True)
+ except NotImplementedError as exc:
+ raise URLPipelineError(
+ f"adapter {last.scheme!r} returned a writable store for mode 'r', "
+ "and the store does not support read-only conversion via "
+ ".with_read_only()"
+ ) from exc
+ await read_only_store._ensure_open()
+ resolution = dataclasses.replace(resolution, store=read_only_store)
+ return resolution
+
+
+async def _resolve_root(
+ segment: PipelineSegment,
+ *,
+ mode: AccessModeLiteral | None,
+ storage_options: dict[str, Any] | None,
+) -> Store:
+ """
+ Resolve the root sub-URL of a pipeline into a store.
+
+ `memory:` and `file:` roots are resolved here with the URL pipeline
+ spec's semantics (spelling equivalences, mandatory absolute `file:`
+ paths); everything else — bare local paths, fsspec URLs — delegates to
+ the existing `StoreLike` machinery unchanged.
+ """
+ if segment.scheme == "memory":
+ return _resolve_memory_root(segment, mode=mode, storage_options=storage_options)
+ from zarr.storage._common import make_store # circular import
+
+ if segment.scheme == "file":
+ # Per the spec: file://localhost/p and file:///p are equivalent to
+ # file:/p; other authorities are unsupported; relative paths are
+ # forbidden; file: URLs carry no query.
+ if segment.query is not None:
+ raise URLPipelineError(f"'file:' pipeline roots do not accept a query: {segment.raw!r}")
+ body = segment.body
+ if body.startswith("//"):
+ authority, sep, rest = body[2:].partition("/")
+ if authority not in ("", "localhost"):
+ raise URLPipelineError(
+ f"unsupported authority {authority!r} in 'file:' pipeline "
+ f"root {segment.raw!r}; only an empty authority or "
+ "'localhost' is allowed"
+ )
+ body = f"/{rest}" if sep else ""
+ # a file URL spells a Windows drive path as /C:/...; strip the
+ # leading slash so the local-path machinery sees the drive
+ if body.startswith("/") and _WINDOWS_DRIVE_RE.match(body[1:]):
+ body = body[1:]
+ if not (body.startswith("/") or _WINDOWS_DRIVE_RE.match(body)):
+ raise URLPipelineError(
+ f"'file:' pipeline roots must carry an absolute path: {segment.raw!r}"
+ )
+ return await make_store(f"file:{body}", mode=mode, storage_options=storage_options)
+
+ try:
+ return await make_store(segment.raw, mode=mode, storage_options=storage_options)
+ except ValueError as exc:
+ raise URLPipelineError(
+ f"could not resolve the pipeline root {segment.raw!r}: {exc}"
+ ) from exc
+
+
+def _resolve_memory_root(
+ segment: PipelineSegment,
+ *,
+ mode: AccessModeLiteral | None,
+ storage_options: dict[str, Any] | None,
+) -> Store:
+ """
+ Resolve a `memory:` pipeline root per the spec's spelling equivalences:
+ `memory:` ≡ `memory:/` ≡ `memory://`, and `memory:a` ≡ `memory:/a` ≡
+ `memory://a`. The first path component names the managed store; the
+ remainder is a path within it.
+ """
+ if segment.query is not None:
+ raise URLPipelineError(f"'memory:' pipeline roots do not accept a query: {segment.raw!r}")
+ if storage_options:
+ raise TypeError(
+ "'storage_options' was provided but unused. "
+ "'storage_options' is only used when the store is passed as an FSSpec URI string.",
+ )
+ name, _, path = segment.body.lstrip("/").partition("/")
+ return ManagedMemoryStore(name=name, path=path, read_only=mode == "r")
diff --git a/tests/package_with_entrypoint-0.1.dist-info/entry_points.txt b/tests/package_with_entrypoint-0.1.dist-info/entry_points.txt
index 7eb0eb7c86..456c725b4e 100644
--- a/tests/package_with_entrypoint-0.1.dist-info/entry_points.txt
+++ b/tests/package_with_entrypoint-0.1.dist-info/entry_points.txt
@@ -13,4 +13,6 @@ another_ndbuffer = package_with_entrypoint:TestEntrypointGroup.NDBuffer
[zarr.codec_pipeline]
another_pipeline = package_with_entrypoint:TestEntrypointGroup.Pipeline
[zarr.data_type]
-new_data_type = package_with_entrypoint:TestDataType
\ No newline at end of file
+new_data_type = package_with_entrypoint:TestDataType
+[zarr.url_adapters]
+example-pkg.entrypoint-scheme = package_with_entrypoint:TestEntrypointURLAdapter
diff --git a/tests/package_with_entrypoint/__init__.py b/tests/package_with_entrypoint/__init__.py
index 23afcf1dc2..cad73d061d 100644
--- a/tests/package_with_entrypoint/__init__.py
+++ b/tests/package_with_entrypoint/__init__.py
@@ -7,6 +7,7 @@
import zarr.core.buffer
from zarr.abc.codec import ArrayBytesCodec, CodecInput, CodecPipeline
+from zarr.abc.url_pipeline import AdapterResolution, URLPipelineAdapter
from zarr.codecs import BytesCodec
from zarr.core.buffer import Buffer, NDBuffer
from zarr.core.dtype.npy.bool import Bool
@@ -16,6 +17,7 @@
from collections.abc import Iterable
from typing import Any, ClassVar, Literal, Self
+ from zarr.abc.url_pipeline import PipelineContext, PipelineSegment
from zarr.core.array_spec import ArraySpec
from zarr.core.common import ZarrFormat
from zarr.core.dtype.common import DTypeJSON, DTypeSpec_V2
@@ -100,3 +102,16 @@ def to_json(self, zarr_format: ZarrFormat) -> str | DTypeSpec_V2: # type: ignor
if zarr_format == 3:
return self._zarr_v3_name
raise ValueError("zarr_format must be 2 or 3")
+
+
+class TestEntrypointURLAdapter(URLPipelineAdapter):
+ """URL pipeline adapter discovered via the zarr.url_adapters entry point."""
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ from zarr.storage import MemoryStore
+
+ store = await MemoryStore.open(read_only=context.read_only)
+ return AdapterResolution(store=store, path=segment.body)
diff --git a/tests/test_api.py b/tests/test_api.py
index 45d0c0dee4..c4e561c180 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -198,6 +198,9 @@ async def test_open_like_creates_array_by_default(
async def test_open_like_default_mode_rejects_read_only_store(
zarr_format: ZarrFormat,
) -> None:
+ # mode "a" (open-or-create) on a read-only store serves the "open" half:
+ # since the node does not exist and creating is impossible, the open
+ # fails with a not-found error rather than rejecting the mode upfront.
ref_arr = zarr.create_array(
store={},
shape=(11, 12),
@@ -206,7 +209,7 @@ async def test_open_like_default_mode_rejects_read_only_store(
zarr_format=zarr_format,
)
- with pytest.raises(ValueError, match="Store is read-only but mode is 'a'"):
+ with pytest.raises(ValueError, match="No array found"):
await zarr.api.asynchronous.open_like(
ref_arr,
path="foo",
diff --git a/tests/test_url_pipeline/__init__.py b/tests/test_url_pipeline/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/test_url_pipeline/conftest.py b/tests/test_url_pipeline/conftest.py
new file mode 100644
index 0000000000..13c717e04e
--- /dev/null
+++ b/tests/test_url_pipeline/conftest.py
@@ -0,0 +1,22 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import pytest
+
+import zarr.registry
+
+if TYPE_CHECKING:
+ from collections.abc import Generator
+
+
+@pytest.fixture
+def clean_url_adapter_registry() -> Generator[None, None, None]:
+ """Snapshot and restore the URL adapter registry around a test."""
+ registry = zarr.registry._url_adapter_registry
+ saved = dict(registry)
+ saved_lazy = list(registry.lazy_load_list)
+ yield
+ registry.clear()
+ registry.update(saved)
+ registry.lazy_load_list[:] = saved_lazy
diff --git a/tests/test_url_pipeline/test_parser.py b/tests/test_url_pipeline/test_parser.py
new file mode 100644
index 0000000000..13d7846e85
--- /dev/null
+++ b/tests/test_url_pipeline/test_parser.py
@@ -0,0 +1,232 @@
+from __future__ import annotations
+
+import sys
+
+import pytest
+from hypothesis import given
+from hypothesis import strategies as st
+
+from zarr.errors import URLPipelineError
+from zarr.storage._url_pipeline import parse_pipeline
+
+
+def test_single_root_url() -> None:
+ (segment,) = parse_pipeline("s3://bucket/key")
+ assert segment.scheme == "s3"
+ assert segment.body == "//bucket/key"
+ assert segment.query is None
+ assert segment.raw == "s3://bucket/key"
+ assert str(segment) == "s3://bucket/key"
+
+
+def test_schemeless_root() -> None:
+ (segment,) = parse_pipeline("/local/path")
+ assert segment.scheme == ""
+ assert segment.body == "/local/path"
+ assert segment.raw == "/local/path"
+
+
+def test_adapter_chain() -> None:
+ segments = parse_pipeline("s3://bucket/data.zip|zip:inner/path|zarr3:")
+ assert [s.scheme for s in segments] == ["s3", "zip", "zarr3"]
+ assert segments[1].body == "inner/path"
+ assert segments[2].body == ""
+
+
+def test_trailing_colon_optional() -> None:
+ with_colon = parse_pipeline("file:/tmp/x.zip|zip:")
+ without_colon = parse_pipeline("file:/tmp/x.zip|zip")
+ assert with_colon[1].scheme == without_colon[1].scheme == "zip"
+ assert with_colon[1].body == without_colon[1].body == ""
+
+
+def test_scheme_case_insensitive() -> None:
+ segments = parse_pipeline("FILE:/tmp/x.zip|ZIP:Inner/Path")
+ assert segments[0].scheme == "file"
+ assert segments[1].scheme == "zip"
+ # bodies are case-preserved
+ assert segments[1].body == "Inner/Path"
+
+
+def test_case_preserved_in_raw() -> None:
+ # e.g. icechunk snapshot IDs are case-significant
+ segments = parse_pipeline("file:/tmp/repo|icechunk://ABCDEFGH12345678ABCD/x")
+ assert segments[1].raw == "icechunk://ABCDEFGH12345678ABCD/x"
+ assert segments[1].body == "//ABCDEFGH12345678ABCD/x"
+
+
+def test_vendor_prefixed_scheme() -> None:
+ segments = parse_pipeline("file:/data|vendor-1.custom+adapter:sub/path")
+ assert segments[1].scheme == "vendor-1.custom+adapter"
+ assert segments[1].body == "sub/path"
+
+
+def test_query_strings() -> None:
+ segments = parse_pipeline("https://example.com/d.zip?token=abc|zip:x?opt=1")
+ assert segments[0].query == "token=abc"
+ assert segments[0].body == "//example.com/d.zip"
+ assert segments[1].query == "opt=1"
+ assert segments[1].body == "x"
+
+
+def test_empty_query() -> None:
+ (segment,) = parse_pipeline("https://example.com/d?")
+ assert segment.query == ""
+
+
+def test_windows_drive_path_is_not_a_scheme() -> None:
+ # On Windows parse_store_url treats C:\... as a local path; elsewhere the
+ # single-letter scheme is preserved but must not crash the parser.
+ (segment,) = parse_pipeline(r"C:\data\store")
+ assert segment.raw == r"C:\data\store"
+ if sys.platform == "win32":
+ assert segment.scheme == ""
+ assert segment.body == r"C:\data\store"
+ else:
+ assert segment.scheme == "c"
+
+
+@pytest.mark.parametrize("url", ["a||b:", "|zip:", "file:/tmp|", ""])
+def test_empty_sub_url_rejected(url: str) -> None:
+ with pytest.raises(URLPipelineError, match="empty sub-URL"):
+ parse_pipeline(url)
+
+
+def test_fragment_rejected() -> None:
+ with pytest.raises(URLPipelineError, match="fragment"):
+ parse_pipeline("file:/tmp/x.zip|zip:inner#frag")
+
+
+@pytest.mark.parametrize("segment", ["1zip:", "zi p:x", "zip@:x"])
+def test_invalid_adapter_scheme_rejected(segment: str) -> None:
+ with pytest.raises(URLPipelineError, match="invalid adapter scheme"):
+ parse_pipeline(f"file:/tmp/x|{segment}")
+
+
+def test_single_letter_scheme_with_exotic_authority() -> None:
+ # single-letter candidates are delegated to parse_store_url, which may
+ # reject an exotic authority; the raw scheme is used as the fallback
+ segments = parse_pipeline("x://[authority]/path|zip:")
+ assert segments[0].scheme in ("", "x")
+ assert segments[0].raw == "x://[authority]/path"
+
+
+def test_fsspec_chained_root_is_opaque() -> None:
+ # fsspec's ``scheme::`` chaining is not pipeline syntax; such roots are
+ # schemeless/opaque and flow through the ordinary store machinery
+ (segment,) = parse_pipeline("zip::file:///tmp/data.zip")
+ assert segment.scheme == ""
+ assert segment.body == "zip::file:///tmp/data.zip"
+
+
+def test_whitespace_prefixed_root_is_opaque() -> None:
+ # urlparse strips leading whitespace when sniffing a scheme; the parser
+ # must not, or the detected scheme desyncs from the body slice
+ segments = parse_pipeline("\tfile:/tmp/x|zip:")
+ assert segments[0].scheme == ""
+ assert segments[0].body == "\tfile:/tmp/x"
+
+
+def test_schemeless_root_keeps_query_and_fragment_chars() -> None:
+ # ? and # are ordinary filename characters in a bare local path
+ segments = parse_pipeline("/tmp/d?v=1|zip:")
+ assert segments[0].scheme == ""
+ assert segments[0].body == "/tmp/d?v=1"
+ assert segments[0].query is None
+ segments = parse_pipeline("/tmp/d#frag|zip:")
+ assert segments[0].body == "/tmp/d#frag"
+
+
+def test_round_trip() -> None:
+ url = "s3://bucket/a.zip?v=2|zip:b/inner.zip|zip:c|zarr3:"
+ segments = parse_pipeline(url)
+ assert "|".join(s.raw for s in segments) == url
+
+
+# --- property-based tests -----------------------------------------------
+#
+# These exercise the parser's *splitting invariants*, not URL pipeline spec
+# validity: parse_pipeline is a permissive segment splitter (bodies and
+# queries are opaque text to it), and semantic validation is left to the
+# resolver and the adapters. Rather than enumerating registered schemes,
+# the strategies sample the full scheme grammar the parser accepts
+# (RFC 3986 plus "." for vendor prefixes), so every valid root/adapter
+# scheme is reachable. Bodies and queries draw from printable ASCII minus
+# the characters the parser itself splits on ("|", "#", and "?" for
+# bodies); the generated text is not required to be a well-formed URI.
+
+_ADAPTER_SCHEME = st.from_regex(r"[a-zA-Z][a-zA-Z0-9+.\-]{0,15}", fullmatch=True)
+# two or more characters, so Windows drive-letter handling cannot reclassify
+# the root scheme as a local path on one platform but not another
+_ROOT_SCHEME = st.from_regex(r"[a-zA-Z]{2}[a-zA-Z0-9+.\-]{0,14}", fullmatch=True)
+_BODY = st.text(st.characters(min_codepoint=32, max_codepoint=126, exclude_characters="|#?"))
+# a root body starting with ":" would spell fsspec's chained-URL syntax
+# ("scheme::..."), which the parser deliberately treats as an opaque root
+_ROOT_BODY = _BODY.filter(lambda body: not body.startswith(":"))
+_QUERY = st.text(st.characters(min_codepoint=32, max_codepoint=126, exclude_characters="|#"))
+
+
+@st.composite
+def pipelines(
+ draw: st.DrawFn, min_depth: int = 1
+) -> tuple[str, list[tuple[str, str, str | None, str]]]:
+ """A parseable pipeline URL up to depth 8, with its expected split."""
+ depth = draw(st.integers(min_value=min_depth, max_value=8))
+ expected = []
+ parts = []
+ for index in range(depth):
+ scheme = draw(_ROOT_SCHEME if index == 0 else _ADAPTER_SCHEME)
+ body = draw(_ROOT_BODY if index == 0 else _BODY)
+ query = draw(st.none() | _QUERY)
+ raw = f"{scheme}:{body}" + (f"?{query}" if query is not None else "")
+ parts.append(raw)
+ expected.append((scheme.lower(), body, query, raw))
+ return "|".join(parts), expected
+
+
+@given(pipelines())
+def test_valid_pipeline_invariants(
+ case: tuple[str, list[tuple[str, str, str | None, str]]],
+) -> None:
+ url, expected = case
+ segments = parse_pipeline(url)
+ # schemes lowercased; bodies and queries preserved verbatim
+ assert [(s.scheme, s.body, s.query, s.raw) for s in segments] == expected
+ # lossless round trip
+ assert "|".join(s.raw for s in segments) == url
+
+
+@given(pipelines(), st.data())
+def test_property_empty_sub_url_rejected(
+ case: tuple[str, list[tuple[str, str, str | None, str]]], data: st.DataObject
+) -> None:
+ url, _ = case
+ parts = url.split("|")
+ parts.insert(data.draw(st.integers(0, len(parts))), "")
+ with pytest.raises(URLPipelineError, match="empty sub-URL"):
+ parse_pipeline("|".join(parts))
+
+
+@given(pipelines(min_depth=2), st.data())
+def test_property_invalid_adapter_scheme_rejected(
+ case: tuple[str, list[tuple[str, str, str | None, str]]], data: st.DataObject
+) -> None:
+ url, _ = case
+ parts = url.split("|")
+ # corrupt one adapter segment's scheme with a leading character the
+ # scheme grammar forbids
+ index = data.draw(st.integers(1, len(parts) - 1))
+ parts[index] = data.draw(st.sampled_from(["1", " ", "@", "~"])) + parts[index]
+ with pytest.raises(URLPipelineError, match="invalid adapter scheme"):
+ parse_pipeline("|".join(parts))
+
+
+@given(pipelines(), st.data())
+def test_property_fragment_rejected(
+ case: tuple[str, list[tuple[str, str, str | None, str]]], data: st.DataObject
+) -> None:
+ url, _ = case
+ parts = url.split("|")
+ parts[data.draw(st.integers(0, len(parts) - 1))] += "#frag"
+ with pytest.raises(URLPipelineError, match="fragment"):
+ parse_pipeline("|".join(parts))
diff --git a/tests/test_url_pipeline/test_resolver.py b/tests/test_url_pipeline/test_resolver.py
new file mode 100644
index 0000000000..198c178764
--- /dev/null
+++ b/tests/test_url_pipeline/test_resolver.py
@@ -0,0 +1,569 @@
+from __future__ import annotations
+
+import dataclasses
+import sys
+from typing import TYPE_CHECKING, ClassVar
+
+import pytest
+
+import zarr
+import zarr.registry
+from zarr.abc.store import Store
+from zarr.abc.url_pipeline import (
+ AdapterResolution,
+ PipelineContext,
+ PipelineSegment,
+ URLPipelineAdapter,
+)
+from zarr.errors import URLPipelineError, ZarrUserWarning
+from zarr.registry import (
+ get_url_adapter,
+ list_url_adapter_schemes,
+ register_url_adapter,
+)
+from zarr.storage import ManagedMemoryStore, MemoryStore, WrapperStore
+from zarr.storage._common import make_store, make_store_path
+from zarr.storage._url_pipeline import is_url_pipeline, resolve_pipeline
+from zarr.storage._utils import _join_paths
+
+if TYPE_CHECKING:
+ from pathlib import Path
+
+pytestmark = pytest.mark.usefixtures("clean_url_adapter_registry")
+
+
+class TracingStore(WrapperStore[Store]):
+ """Wrapper that records the context it was created from."""
+
+ context: PipelineContext
+ segment: PipelineSegment
+
+
+class WrapperAdapter(URLPipelineAdapter):
+ """
+ A wrapper-style adapter: resolves the preceding pipeline into a store.
+
+ Follows the wrapper contract: the preceding resolution's residual path
+ is carried forward (joined with this segment's own path), and unchanged
+ fields survive via `dataclasses.replace`.
+ """
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ preceding = await context.resolve_preceding()
+ store = TracingStore(preceding.store)
+ store.context = context
+ store.segment = segment
+ return dataclasses.replace(
+ preceding, store=store, path=_join_paths([preceding.path, segment.body])
+ )
+
+
+class NativeAdapter(URLPipelineAdapter):
+ """A native-style adapter: consumes the preceding URL as a string."""
+
+ seen_urls: ClassVar[list[str]] = []
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ cls.seen_urls.append(context.preceding_url)
+ store = await MemoryStore.open(read_only=context.read_only)
+ return AdapterResolution(store=store, path=segment.body)
+
+
+class RootAdapter(URLPipelineAdapter):
+ """A root-scheme adapter (no preceding segments), like al://."""
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ assert context.preceding == ()
+ if context.mode in ("w", "w-", "r+"):
+ raise ValueError("read-only scheme")
+ store = await MemoryStore.open(read_only=True)
+ return AdapterResolution(store=store, path=segment.body.lstrip("/"))
+
+
+class DisobedientAdapter(URLPipelineAdapter):
+ """An adapter that ignores `context.read_only` (a contract violation)."""
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ return AdapterResolution(store=await MemoryStore.open(read_only=False))
+
+
+class FormatAdapter(URLPipelineAdapter):
+ """A dummy format-selecting adapter, like the builtin `zarr2:`."""
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ preceding = await context.resolve_preceding()
+ return dataclasses.replace(preceding, zarr_format=2)
+
+
+class TestRegistry:
+ def test_register_and_get(self) -> None:
+ register_url_adapter("demo", WrapperAdapter)
+ assert get_url_adapter("demo") is WrapperAdapter
+ assert get_url_adapter("DEMO") is WrapperAdapter
+ assert "demo" in list_url_adapter_schemes()
+
+ def test_unknown_scheme(self) -> None:
+ with pytest.raises(URLPipelineError, match="no URL pipeline adapter is registered"):
+ get_url_adapter("nonexistent-scheme")
+
+ def test_reregistering_scheme_warns(self) -> None:
+ register_url_adapter("demo", WrapperAdapter)
+ with pytest.warns(ZarrUserWarning, match="is being replaced"):
+ register_url_adapter("demo", NativeAdapter)
+ assert get_url_adapter("demo") is NativeAdapter
+ # re-registering the same class is not a collision
+ register_url_adapter("demo", NativeAdapter)
+
+ @pytest.mark.usefixtures("set_path")
+ def test_entrypoint_discovery(self) -> None:
+ assert "example-pkg.entrypoint-scheme" in list_url_adapter_schemes()
+ cls = get_url_adapter("example-pkg.entrypoint-scheme")
+ assert cls.__name__ == "TestEntrypointURLAdapter"
+
+ @pytest.mark.usefixtures("set_path")
+ async def test_entrypoint_end_to_end(self) -> None:
+ result = await resolve_pipeline("memory://src|example-pkg.entrypoint-scheme:sub/path")
+ assert result.path == "sub/path"
+
+ @pytest.mark.usefixtures("set_path")
+ def test_entrypoint_scheme_lookup_is_case_insensitive(self) -> None:
+ # entry-point names are matched case-insensitively, like schemes
+ cls = get_url_adapter("Example-PKG.Entrypoint-Scheme")
+ assert cls.__name__ == "TestEntrypointURLAdapter"
+
+ @pytest.mark.usefixtures("set_path")
+ def test_loading_one_scheme_leaves_others_pending(self) -> None:
+ # resolving one scheme must not import other providers' entry points
+ registry = zarr.registry._url_adapter_registry
+ assert any(e.name == "example-pkg.entrypoint-scheme" for e in registry.lazy_load_list)
+ with pytest.raises(URLPipelineError, match="no URL pipeline adapter"):
+ get_url_adapter("some-other-scheme")
+ assert any(e.name == "example-pkg.entrypoint-scheme" for e in registry.lazy_load_list)
+ assert get_url_adapter("example-pkg.entrypoint-scheme").__name__ == (
+ "TestEntrypointURLAdapter"
+ )
+
+
+class TestIsURLPipeline:
+ def test_pipe_routes(self) -> None:
+ assert is_url_pipeline("memory://x|demo:")
+
+ def test_registered_root_scheme_routes(self) -> None:
+ register_url_adapter("rooty", RootAdapter)
+ assert is_url_pipeline("rooty://org/repo")
+
+ @pytest.mark.parametrize("url", ["s3://bucket/key", "/local/path", "memory://x", "C:.zarr"])
+ def test_plain_urls_do_not_route(self, url: str) -> None:
+ assert not is_url_pipeline(url)
+
+ def test_fsspec_chained_urls_do_not_route(self) -> None:
+ # fsspec's ``scheme::`` chaining is not a URL pipeline: even with a
+ # same-named root adapter registered, these keep flowing to fsspec.
+ register_url_adapter("zip", RootAdapter)
+ assert not is_url_pipeline("zip::file:///tmp/data.zip")
+ assert not is_url_pipeline("simplecache::s3://bucket/key")
+
+ def test_native_schemes_do_not_route_to_adapters(self) -> None:
+ # an installed package must not be able to intercept zarr's own
+ # local-path and in-memory routing by registering file:/memory:
+ register_url_adapter("file", RootAdapter)
+ register_url_adapter("memory", RootAdapter)
+ assert not is_url_pipeline("file:/tmp/x")
+ assert not is_url_pipeline("memory://x")
+
+ def test_exotic_authority_root_scheme(self) -> None:
+ # The spec's own root-URL example: urlparse rejects the bracketed
+ # non-IP authority, so scheme detection must work on the raw string
+ # rather than raising before routing.
+ url = "vendor1-2.custom-1+proto.ext://[authority]/path?query/part?x"
+ assert not is_url_pipeline(url)
+ register_url_adapter("vendor1-2.custom-1+proto.ext", RootAdapter)
+ assert is_url_pipeline(url)
+
+
+class TestResolve:
+ async def test_wrapper_adapter_chain(self, tmp_path: Path) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ result = await resolve_pipeline(f"{tmp_path}|wrap:inner/path")
+ assert isinstance(result.store, TracingStore)
+ assert result.path == "inner/path"
+ assert result.store.context.preceding_url == str(tmp_path)
+
+ async def test_nested_wrappers_preserve_residual_paths(self, tmp_path: Path) -> None:
+ # each wrapper joins the preceding residual path with its own, so
+ # no segment's path is lost in root|wrap:a|wrap:b
+ register_url_adapter("wrap", WrapperAdapter)
+ result = await resolve_pipeline(f"{tmp_path}|wrap:a|wrap:b")
+ assert result.path == "a/b"
+
+ async def test_native_adapter_gets_preceding_url(self) -> None:
+ register_url_adapter("native", NativeAdapter)
+ NativeAdapter.seen_urls.clear()
+ await resolve_pipeline("s3://bucket/repo|native:")
+ assert NativeAdapter.seen_urls == ["s3://bucket/repo"]
+
+ async def test_multi_segment_preceding_url(self) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ register_url_adapter("native", NativeAdapter)
+ NativeAdapter.seen_urls.clear()
+ await resolve_pipeline("memory://base|wrap:a|native:x")
+ assert NativeAdapter.seen_urls == ["memory://base|wrap:a"]
+
+ async def test_root_adapter(self) -> None:
+ register_url_adapter("rooty", RootAdapter)
+ result = await resolve_pipeline("rooty://org/repo")
+ assert result.path == "org/repo"
+ assert result.store.read_only
+
+ async def test_root_adapter_composes_with_chain(self) -> None:
+ register_url_adapter("rooty", RootAdapter)
+ register_url_adapter("native", NativeAdapter)
+ NativeAdapter.seen_urls.clear()
+ await resolve_pipeline("rooty://org/repo|native:x")
+ assert NativeAdapter.seen_urls == ["rooty://org/repo"]
+
+ async def test_read_only_flag(self, tmp_path: Path) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ result = await resolve_pipeline(f"{tmp_path}|wrap:", mode="r")
+ assert isinstance(result.store, TracingStore)
+ assert result.store.context.read_only
+ assert result.store.context.mode == "r"
+ result = await resolve_pipeline(f"{tmp_path}|wrap:")
+ assert isinstance(result.store, TracingStore)
+ assert not result.store.context.read_only
+ assert result.store.context.mode is None
+
+ async def test_read_only_is_enforced_on_disobedient_adapters(self) -> None:
+ # the resolver downgrades a writable store returned under mode "r"
+ # instead of trusting the adapter to have honored context.read_only
+ register_url_adapter("bad", DisobedientAdapter)
+ result = await resolve_pipeline("memory://base|bad:", mode="r")
+ assert result.store.read_only
+ store = await make_store("memory://base|bad:", mode="r")
+ assert store.read_only
+
+ async def test_read_only_enforcement_without_conversion_raises(self) -> None:
+ # a disobedient adapter whose store cannot be converted read-only
+ class StubbornStore(MemoryStore):
+ def with_read_only(self, read_only: bool = False) -> MemoryStore:
+ raise NotImplementedError
+
+ class StubbornAdapter(URLPipelineAdapter):
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ return AdapterResolution(store=await StubbornStore.open(read_only=False))
+
+ register_url_adapter("stubborn", StubbornAdapter)
+ with pytest.raises(URLPipelineError, match="does not support read-only conversion"):
+ await resolve_pipeline("memory://base|stubborn:", mode="r")
+
+ async def test_resolve_preceding_mode_override(self, tmp_path: Path) -> None:
+ # a wrapper that only reads the preceding resource can open it
+ # read-only regardless of the caller's mode
+ class ReadOnlyRootWrapper(WrapperAdapter):
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ preceding = await context.resolve_preceding(mode="r")
+ assert preceding.store.read_only
+ return dataclasses.replace(preceding, path=segment.body)
+
+ register_url_adapter("rowrap", ReadOnlyRootWrapper)
+ result = await resolve_pipeline(f"{tmp_path}|rowrap:x", mode="w")
+ assert result.path == "x"
+
+ async def test_resolve_preceding_storage_options_override(self, tmp_path: Path) -> None:
+ # an adapter that consumed its namespaced keys strips them before
+ # the root store ever sees them
+ class ConsumingWrapper(WrapperAdapter):
+ seen: ClassVar[object | None] = None
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ options = dict(context.storage_options or {})
+ cls.seen = options.pop("consuming_secret", None)
+ preceding = await context.resolve_preceding(storage_options=options or None)
+ return dataclasses.replace(preceding, path=segment.body)
+
+ register_url_adapter("consuming", ConsumingWrapper)
+ # the local-path root rejects any surviving storage_options, so this
+ # passing proves the adapter's keys were stripped before resolution
+ result = await resolve_pipeline(
+ f"{tmp_path}|consuming:x", storage_options={"consuming_secret": "s3cr3t"}
+ )
+ assert result.path == "x"
+ assert ConsumingWrapper.seen == "s3cr3t"
+
+ async def test_storage_options_visible_to_adapter(self) -> None:
+ register_url_adapter("native", NativeAdapter)
+
+ class OptionsProbe(NativeAdapter):
+ seen_options: dict[str, object] | None = None
+
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ cls.seen_options = context.storage_options
+ return await super().open_pipeline_segment(segment, context)
+
+ register_url_adapter("probe", OptionsProbe)
+ opts = {"anon": True}
+ await resolve_pipeline("s3://bucket/x|probe:", storage_options=opts)
+ assert OptionsProbe.seen_options == opts
+
+ async def test_wrapper_at_root_position_raises(self) -> None:
+ # a wrapper adapter used as the pipeline root has nothing to wrap
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(URLPipelineError, match="no preceding sub-URL"):
+ await resolve_pipeline("wrap:whatever")
+
+ async def test_not_a_pipeline_raises(self) -> None:
+ with pytest.raises(URLPipelineError, match="is not a URL pipeline"):
+ await resolve_pipeline("s3://bucket/plain")
+
+ async def test_unknown_adapter_scheme_raises(self) -> None:
+ with pytest.raises(URLPipelineError, match="no URL pipeline adapter is registered"):
+ await resolve_pipeline("memory://base|no-such-adapter:")
+
+ async def test_unknown_adapter_error_hints_at_reserved_pipe(self, tmp_path: Path) -> None:
+ # a filename containing '|' routes here; the error points at the fix
+ with pytest.raises(URLPipelineError, match="pass a\\s+pathlib.Path"):
+ await resolve_pipeline(f"{tmp_path}/a|b")
+
+ async def test_base_case_value_error_is_wrapped(self) -> None:
+ # a root that only the fallback scheme detection accepts must not
+ # leak urlparse's ValueError out of the base case
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(URLPipelineError, match="could not resolve the pipeline root"):
+ await resolve_pipeline("vendor.x://[authority]/path|wrap:")
+
+ async def test_zarr_format_flows_from_adapter(self, tmp_path: Path) -> None:
+ register_url_adapter("fmt2", FormatAdapter)
+ result = await resolve_pipeline(f"{tmp_path}|fmt2:")
+ assert result.zarr_format == 2
+ # wrapper adapters carry the format through (dataclasses.replace)
+ register_url_adapter("wrap", WrapperAdapter)
+ result = await resolve_pipeline(f"{tmp_path}|fmt2:|wrap:")
+ assert result.zarr_format == 2
+
+
+class TestSpecRoots:
+ """The spec's `memory:` / `file:` root semantics inside pipelines."""
+
+ @pytest.mark.parametrize("root", ["memory:", "memory:/", "memory://"])
+ async def test_memory_root_spellings_equivalent(self, root: str) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ result = await resolve_pipeline(f"{root}|wrap:")
+ assert isinstance(result.store, TracingStore)
+ inner = result.store._store
+ assert isinstance(inner, ManagedMemoryStore)
+ assert inner._name == ""
+ assert inner.path == ""
+
+ @pytest.mark.parametrize("root", ["memory:a/b", "memory:/a/b", "memory://a/b"])
+ async def test_memory_root_named_spellings_equivalent(self, root: str) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ result = await resolve_pipeline(f"{root}|wrap:")
+ assert isinstance(result.store, TracingStore)
+ inner = result.store._store
+ assert isinstance(inner, ManagedMemoryStore)
+ assert inner._name == "a"
+ assert inner.path == "b"
+
+ async def test_memory_root_shares_data_across_spellings(self) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ group = zarr.open_group("memory:pipe-share|wrap:", mode="w")
+ group.create_array("x", shape=(2,), dtype="i4")
+ reopened = zarr.open_group("memory://pipe-share|wrap:", mode="r")
+ assert "x" in reopened
+
+ async def test_memory_root_rejects_query(self) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(URLPipelineError, match="do not accept a query"):
+ await resolve_pipeline("memory:a?opt=1|wrap:")
+
+ async def test_memory_root_rejects_storage_options(self) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(TypeError, match="'storage_options' was provided but unused"):
+ await resolve_pipeline("memory:a|wrap:", storage_options={"anon": True})
+
+ async def test_file_root_localhost_authority(self, tmp_path: Path) -> None:
+ # file://localhost/p and file:///p are equivalent to file:/p
+ register_url_adapter("wrap", WrapperAdapter)
+ # spell the path URL-style: on Windows C:/... gains a leading slash
+ posix = tmp_path.as_posix()
+ url_path = posix if posix.startswith("/") else f"/{posix}"
+ zarr.open_group(f"file://localhost{url_path}|wrap:", mode="w")
+ opened = zarr.open_group(f"file:{tmp_path}|wrap:", mode="r")
+ assert isinstance(opened, zarr.Group)
+ zarr.open_group(f"file://{url_path}|wrap:", mode="r")
+
+ async def test_file_root_windows_drive_spellings(
+ self, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+ ) -> None:
+ # Windows drive paths count as absolute, and the URL spelling
+ # file:///C:/... has its leading slash stripped before the drive
+ register_url_adapter("wrap", WrapperAdapter)
+ if sys.platform == "win32":
+ drive_path = tmp_path.as_posix() # C:/Users/...
+ else:
+ # off Windows a drive path is just an odd relative directory;
+ # chdir into tmp so it is created there
+ monkeypatch.chdir(tmp_path)
+ drive_path = "C:/drive/data"
+ r1 = await resolve_pipeline(f"file:{drive_path}|wrap:")
+ r2 = await resolve_pipeline(f"file:///{drive_path}|wrap:")
+ assert isinstance(r1.store, TracingStore)
+ assert isinstance(r2.store, TracingStore)
+
+ async def test_file_root_rejects_other_authority(self) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(URLPipelineError, match="unsupported authority"):
+ await resolve_pipeline("file://example.com/tmp/x|wrap:")
+
+ @pytest.mark.parametrize("root", ["file:relative/path", "file://localhost"])
+ async def test_file_root_rejects_relative_paths(self, root: str) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(URLPipelineError, match="absolute path"):
+ await resolve_pipeline(f"{root}|wrap:")
+
+ async def test_file_root_rejects_query(self, tmp_path: Path) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(URLPipelineError, match="do not accept a query"):
+ await resolve_pipeline(f"file:{tmp_path}?v=1|wrap:")
+
+
+class TestMakeStoreIntegration:
+ async def test_make_store_path_combines_paths(self, tmp_path: Path) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ store_path = await make_store_path(f"{tmp_path}|wrap:residual", path="user/sub")
+ assert store_path.path == "residual/user/sub"
+
+ async def test_make_store_rejects_residual_path(self, tmp_path: Path) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(URLPipelineError, match="resolves to a path inside a store"):
+ await make_store(f"{tmp_path}|wrap:residual")
+
+ async def test_make_store_rejects_slash_root_path(self, tmp_path: Path) -> None:
+ # an adapter returning path="/" addresses the store root; the raw
+ # value is normalized before the residual-path rejection
+ class SlashRootAdapter(WrapperAdapter):
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ preceding = await context.resolve_preceding()
+ return dataclasses.replace(preceding, path="/")
+
+ register_url_adapter("slashy", SlashRootAdapter)
+ store = await make_store(f"{tmp_path}|slashy:")
+ assert store is not None
+
+ async def test_make_store_closes_store_on_residual_path_error(self) -> None:
+ closed: list[bool] = []
+
+ class ClosingStore(MemoryStore):
+ def close(self) -> None:
+ closed.append(True)
+ super().close()
+
+ class LeakProbe(URLPipelineAdapter):
+ @classmethod
+ async def open_pipeline_segment(
+ cls, segment: PipelineSegment, context: PipelineContext
+ ) -> AdapterResolution:
+ return AdapterResolution(store=await ClosingStore.open(), path="residual")
+
+ register_url_adapter("leaky", LeakProbe)
+ with pytest.raises(URLPipelineError, match="resolves to a path inside a store"):
+ await make_store("memory://base|leaky:")
+ assert closed == [True]
+
+ async def test_make_store_no_residual_path(self, tmp_path: Path) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ store = await make_store(f"{tmp_path}|wrap:")
+ assert isinstance(store, TracingStore)
+
+ async def test_zarr_open_end_to_end(self, tmp_path: Path) -> None:
+ register_url_adapter("wrap", WrapperAdapter)
+ group = zarr.open_group(f"{tmp_path}|wrap:", mode="w")
+ array = group.create_array("x", shape=(4,), dtype="i4")
+ array[:] = [1, 2, 3, 4]
+ assert zarr.open_array(f"{tmp_path}|wrap:x")[2] == 3
+
+ async def test_pipeline_store_read_only_mode(self) -> None:
+ register_url_adapter("native", NativeAdapter)
+ store_path = await make_store_path("memory://base|native:", mode="r")
+ assert store_path.read_only
+
+ async def test_mode_a_downgrades_to_read_only_open(self) -> None:
+ # mode "a" (the zarr.open default) is open-or-create: a pipeline
+ # that resolves to a read-only store serves the "open" half instead
+ # of failing outright.
+ register_url_adapter("rooty", RootAdapter)
+ store_path = await make_store_path("rooty://org/repo", mode="a")
+ assert store_path.read_only
+
+ async def test_mode_a_downgrade_applies_to_plain_stores_too(self) -> None:
+ # the open-or-create downgrade lives in StorePath.open, so it is
+ # uniform across pipeline and non-pipeline stores
+ store = await MemoryStore.open(read_only=True)
+ store_path = await make_store_path(store, mode="a")
+ assert store_path.read_only
+
+ async def test_explicit_write_mode_reaches_adapter(self) -> None:
+ register_url_adapter("rooty", RootAdapter)
+ with pytest.raises(ValueError, match="read-only scheme"):
+ await make_store_path("rooty://org/repo", mode="w")
+
+ async def test_storage_options_forwarded_to_root(self) -> None:
+ # storage_options reach the root sub-URL via resolve_preceding ->
+ # make_store. A local-path root does not accept storage_options, so
+ # forwarding them must raise the same TypeError as a non-pipeline open.
+ register_url_adapter("wrap", WrapperAdapter)
+ with pytest.raises(TypeError, match="'storage_options' was provided but unused"):
+ await make_store("/tmp/some/path|wrap:", storage_options={"anon": True})
+
+ async def test_store_path_truediv_keeps_format(self, tmp_path: Path) -> None:
+ # StorePath.__truediv__ constructs a new instance; the pipeline-
+ # selected format must survive the division
+ register_url_adapter("fmt2", FormatAdapter)
+ store_path = await make_store_path(f"{tmp_path}|fmt2:")
+ assert store_path.zarr_format == 2
+ assert (store_path / "sub/node").zarr_format == 2
+
+ async def test_zarr_format_merges_into_open(self, tmp_path: Path) -> None:
+ register_url_adapter("fmt2", FormatAdapter)
+ group = zarr.open_group(f"{tmp_path}|fmt2:", mode="w")
+ assert group.metadata.zarr_format == 2
+
+ async def test_conflicting_explicit_format_raises(self, tmp_path: Path) -> None:
+ register_url_adapter("fmt2", FormatAdapter)
+ with pytest.raises(ValueError, match="conflicts with"):
+ zarr.open_group(f"{tmp_path}|fmt2:", mode="w", zarr_format=3)
+
+ async def test_matching_explicit_format_ok(self, tmp_path: Path) -> None:
+ register_url_adapter("fmt2", FormatAdapter)
+ group = zarr.open_group(f"{tmp_path}|fmt2:", mode="w", zarr_format=2)
+ assert group.metadata.zarr_format == 2
diff --git a/tests/test_url_pipeline/test_spec_examples.py b/tests/test_url_pipeline/test_spec_examples.py
new file mode 100644
index 0000000000..5538074bea
--- /dev/null
+++ b/tests/test_url_pipeline/test_spec_examples.py
@@ -0,0 +1,258 @@
+"""
+Conformance tests against the URL pipeline specification.
+
+Every entry in `SPEC_EXAMPLES` is an example URL from the specification
+repository (https://github.com/jbms/url-pipeline @ 1a01ce6), extracted
+with the same rule as the spec's own linter (`scripts/lint.py`): backticked
+examples on bullet lines, skipping spans without a `:` or `|`. The spec
+validates each example (and an uppercased-scheme variant) against its ABNF
+grammar, so this corpus is grammar-valid by construction.
+
+The parser must accept every example — including schemes zarr-python has no
+adapter for, since parsing is independent of adapter availability — split it
+into the expected sub-URL schemes, and preserve the text losslessly.
+
+To regenerate after a spec update: extract examples per the rule above and
+recompute the expected scheme tuples with `parse_pipeline`, reviewing any
+changes against the spec diff.
+"""
+
+from __future__ import annotations
+
+import re
+
+import pytest
+
+from zarr.storage._url_pipeline import parse_pipeline
+
+SPEC_EXAMPLES: list[tuple[str, tuple[str, ...]]] = [
+ # README.md
+ ("s3://bucket/path/to/archive.zip|zip:path/within/zip.zarr/|zarr3:", ("s3", "zip", "zarr3")),
+ (
+ "file:///tmp/dataset.ocdbt/|ocdbt://2025-01-01T01:23:45.678Z/path/within/database",
+ ("file", "ocdbt"),
+ ),
+ (
+ "s3+https://example.com/path/to/database.icechunk/|icechunk://tag.v5/path/to/node/|zarr3:",
+ ("s3+https", "icechunk", "zarr3"),
+ ),
+ (
+ "vendor1-2.custom-1+proto.ext://[authority]/path?query/part?x",
+ ("vendor1-2.custom-1+proto.ext",),
+ ),
+ (
+ "http://example.com/file|vendor1-2.custom+adapter:/path/within/adapter",
+ ("http", "vendor1-2.custom+adapter"),
+ ),
+ ("a.b:?", ("a.b",)),
+ ("http://somehost/downloads/somefile.zip|zip:", ("http", "zip")),
+ ("http://example.com/archive.jar|zip:path/to/file.txt", ("http", "zip")),
+ ("https://host/archive.zip|zip:path/in/outer.zip|zip:path/in/inner", ("https", "zip", "zip")),
+ ("file:///path/to/archive.zip|zip:path/within/archive", ("file", "zip")),
+ # avif.md
+ ("file:/path/to/image.avif|avif:", ("file", "avif")),
+ ("file:/path/to/image.avif|avif", ("file", "avif")),
+ # bmp.md
+ ("file:/path/to/image.bmp|bmp:", ("file", "bmp")),
+ ("file:/path/to/image.bmp|bmp", ("file", "bmp")),
+ # byte-range.md
+ ("file:/path/to/data|byte-range:1000-2000", ("file", "byte-range")),
+ ("file:/path/to/data|byte-range:0-1", ("file", "byte-range")),
+ # file.md
+ ("file:/", ("file",)),
+ ("file:/a", ("file",)),
+ ("file:/path/to/file.txt", ("file",)),
+ ("file://localhost/path/to/file.txt", ("file",)),
+ ("file://LOCALHOST/path/to/file.txt", ("file",)),
+ ("file:///path/to/file.txt", ("file",)),
+ ("file://somehost/sharename/path/to/file.txt", ("file",)),
+ # gs.md
+ ("gs://bucket", ("gs",)),
+ ("gs://bucket/", ("gs",)),
+ ("gs://bucket/path/within/bucket", ("gs",)),
+ ("gs://aaa", ("gs",)),
+ (
+ "gs://label1-is-sixty-two-characters-long-xxxxxxxxxxxxxxxxxxxxxxxxxx.label2-is-sixty-two-characters-long-yyyyyyyyyyyyyyyyyyyyyyyyyy.label3-is-sixty-two-characters-long-zzzzzzzzzzzzzzzzzzzzzzzzzz.label4-is-thirty-one-characters",
+ ("gs",),
+ ),
+ # gzip.md
+ ("file:/path/to/data.gz|gzip:", ("file", "gzip")),
+ ("file:/path/to/data.gz|gzip", ("file", "gzip")),
+ # hdf5.md
+ ("s3://bucket/path/to/file.h5|hdf5:/path/to/dataset", ("s3", "hdf5")),
+ ("s3://bucket/path/to/file.h5|hdf5:a", ("s3", "hdf5")),
+ ("file:///path/to/file.h5|hdf5:", ("file", "hdf5")),
+ ("file:///path/to/file.h5|hdf5", ("file", "hdf5")),
+ # http.md
+ ("https://example.com/path/to/resource%20name", ("https",)),
+ ("https://example.com/path/to/resource?query=value", ("https",)),
+ ("https://example.com/path/to/?query=value", ("https",)),
+ ("https://example.com/path/with:colon", ("https",)),
+ ("https://server.example.com:1234/path/to/array", ("https",)),
+ ("http://a", ("http",)),
+ ("http://example.com", ("http",)),
+ ("http://local%68ost", ("http",)),
+ ("http://example.com:", ("http",)),
+ ("http://192.168.10.1:1234", ("http",)),
+ ("http://[::1]", ("http",)),
+ ("http://[::ffff:127.0.0.1]", ("http",)),
+ ("http://example.com/", ("http",)),
+ # icechunk.md
+ ("file:///path/to/repo.zarr.icechunk/|icechunk:", ("file", "icechunk")),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk", ("file", "icechunk")),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk://branch.main/", ("file", "icechunk")),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk:path/to/node/", ("file", "icechunk")),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk:a", ("file", "icechunk")),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk:/path/to/node/", ("file", "icechunk")),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk:path/to/node/zarr.json", ("file", "icechunk")),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk:path/to/node/c/0/0/1", ("file", "icechunk")),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk://branch.mybranch/path/to/node/",
+ ("file", "icechunk"),
+ ),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk://branch.a", ("file", "icechunk")),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk://tag.mytag/path/to/node/",
+ ("file", "icechunk"),
+ ),
+ ("file:///path/to/repo.zarr.icechunk/|icechunk://tag.a", ("file", "icechunk")),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk://FWWFQGAW742XMX0F5MF0/path/to/node/",
+ ("file", "icechunk"),
+ ),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk://ABCDEFGHJKMNPQRSTVWX/path/to/node/",
+ ("file", "icechunk"),
+ ),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk:|zarr3:path/to/array/",
+ ("file", "icechunk", "zarr3"),
+ ),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk://branch.other/|zarr3:path/to/array/",
+ ("file", "icechunk", "zarr3"),
+ ),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk://tag.v5/|zarr3:path/to/array/",
+ ("file", "icechunk", "zarr3"),
+ ),
+ (
+ "file:///path/to/repo.zarr.icechunk/|icechunk://4N0217AZA4VNPYD0HR0G/|zarr3:path/to/array/",
+ ("file", "icechunk", "zarr3"),
+ ),
+ # jpeg.md
+ ("file:/path/to/image.jpeg|jpeg:", ("file", "jpeg")),
+ ("file:/path/to/image.jpeg|jpeg", ("file", "jpeg")),
+ # json.md
+ ("file:/path/to/data.json|json:", ("file", "json")),
+ ("file:/path/to/data.json|json", ("file", "json")),
+ ("file:/path/to/data.json|json:/path/to/node", ("file", "json")),
+ ("file:/path/to/data.json|json:/abc~0def", ("file", "json")),
+ ("file:/path/to/data.json|json:/abc~1def", ("file", "json")),
+ ("file:/path/to/data.json|json:/", ("file", "json")),
+ # memory.md
+ ("memory:", ("memory",)),
+ ("memory:/", ("memory",)),
+ ("memory://", ("memory",)),
+ ("memory:path/to/resource", ("memory",)),
+ ("memory:a", ("memory",)),
+ ("memory:another@path+with,lots&of(special;characters)*_!-$'", ("memory",)),
+ ("memory:/path/to/resource", ("memory",)),
+ ("memory://path/to/resource", ("memory",)),
+ # n5.md
+ ("file:///tmp/data.n5/|n5:path/to/array", ("file", "n5")),
+ ("file:///tmp/data.n5/|n5:a", ("file", "n5")),
+ ("file:///tmp/data.n5/|n5:/path/to/array", ("file", "n5")),
+ ("file:///tmp/data.n5/|n5:", ("file", "n5")),
+ ("file:///tmp/data.n5/|n5", ("file", "n5")),
+ # neuroglancer-precomputed.md
+ (
+ "file:///tmp/dataset.precomputed/|neuroglancer-precomputed:",
+ ("file", "neuroglancer-precomputed"),
+ ),
+ (
+ "file:///tmp/dataset.precomputed/|neuroglancer-precomputed",
+ ("file", "neuroglancer-precomputed"),
+ ),
+ # ocdbt.md
+ ("file:///path/to/repo.ocdbt/|ocdbt:", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt:path/within/repo/", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt:path/within/repo", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt:a", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt:/path/within/repo", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt://v123/", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt://v1", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt://v123/path/within/repo", ("file", "ocdbt")),
+ (
+ "file:///path/to/repo.ocdbt/|ocdbt://2025-01-01T01:23:45.678Z/path/within/database",
+ ("file", "ocdbt"),
+ ),
+ ("file:///path/to/repo.ocdbt/|ocdbt://2025-01-01T01:23:45Z", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt://2025-01-01T01:23:45.1Z", ("file", "ocdbt")),
+ ("file:///path/to/repo.ocdbt/|ocdbt://2025-01-01T01:23:45.123456789Z", ("file", "ocdbt")),
+ # png.md
+ ("file:/path/to/image.png|png:", ("file", "png")),
+ ("file:/path/to/image.png|png", ("file", "png")),
+ # s3+http.md
+ ("s3+https://endpoint/path/within/bucket", ("s3+https",)),
+ ("s3+https://endpoint/bucket/path/within/bucket", ("s3+https",)),
+ ("s3+https://mybucket.s3.amazonaws.com/path/to/file", ("s3+https",)),
+ ("s3+https://s3.amazonaws.com/mybucket/path/to/file", ("s3+https",)),
+ ("s3+http://example.com", ("s3+http",)),
+ ("s3+http://example.com/", ("s3+http",)),
+ # s3.md
+ ("s3://bucket", ("s3",)),
+ ("s3://bucket/", ("s3",)),
+ ("s3://bucket/path/within/bucket", ("s3",)),
+ ("s3://aaa", ("s3",)),
+ (
+ "s3://aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+ ("s3",),
+ ),
+ # tiff.md
+ ("file:/path/to/image.tiff|tiff:", ("file", "tiff")),
+ ("file:/path/to/image.tiff|tiff", ("file", "tiff")),
+ # webp.md
+ ("file:/path/to/image.webp|webp:", ("file", "webp")),
+ ("file:/path/to/image.webp|webp", ("file", "webp")),
+ # zarr.md
+ ("file:///path/to/node.zarr/|zarr3:", ("file", "zarr3")),
+ ("file:///path/to/node.zarr/|zarr3", ("file", "zarr3")),
+ ("file:///path/to/node.zarr/|zarr2:", ("file", "zarr2")),
+ ("file:///path/to/node.zarr/|zarr2", ("file", "zarr2")),
+ ("file:///path/to/node.zarr/|zarr:", ("file", "zarr")),
+ ("file:///path/to/node.zarr/|zarr", ("file", "zarr")),
+ # zip.md
+ ("file:/path/to/archive.zip|zip:path/to/file.txt", ("file", "zip")),
+ ("file:/path/to/archive.zip|zip", ("file", "zip")),
+ ("file:/path/to/archive.zip|zip:/path/to/file.txt", ("file", "zip")),
+ ("file:/path/to/outer.zip|zip:path/to/inner.zip|zip:path/to/file.txt", ("file", "zip", "zip")),
+ # zstd.md
+ ("file:/path/to/data.zstd|zstd:", ("file", "zstd")),
+ ("file:/path/to/data.zstd|zstd", ("file", "zstd")),
+]
+
+
+def _uppercase_schemes(example: str) -> str:
+ """Uppercase every sub-URL scheme, as the spec's linter does."""
+
+ def repl(match: re.Match[str]) -> str:
+ return match.group(1) + match.group(2).upper()
+
+ return re.sub(r"((?:^|\|)\s*)([a-zA-Z][a-zA-Z0-9+.-]*)", repl, example)
+
+
+@pytest.mark.parametrize(("url", "expected_schemes"), SPEC_EXAMPLES, ids=lambda v: str(v))
+def test_spec_example_parses(url: str, expected_schemes: tuple[str, ...]) -> None:
+ segments = parse_pipeline(url)
+ assert tuple(segment.scheme for segment in segments) == expected_schemes
+ # lossless round-trip of the original text
+ assert "|".join(segment.raw for segment in segments) == url
+
+
+@pytest.mark.parametrize(("url", "expected_schemes"), SPEC_EXAMPLES, ids=lambda v: str(v))
+def test_spec_example_schemes_case_insensitive(url: str, expected_schemes: tuple[str, ...]) -> None:
+ upper = _uppercase_schemes(url)
+ segments = parse_pipeline(upper)
+ assert tuple(segment.scheme for segment in segments) == expected_schemes