Add Docker Compose language support

[eth0net]

Moves Docker Compose support in from
eth0net/zed-docker-compose, per
the discussion on zed-industries/extensions#7105. Thanks @MrSubidubi — you were
right that shipping the language server twice was the wrong shape.

What's here

A Docker Compose language, matched on compose.yaml, compose.yml,
docker-compose.yaml and docker-compose.yml. Its own language rather than an
extension of YAML, which is what keeps the server off plain YAML files — the
original extension attached to YAML wholesale and that caused unresolved-tag
warnings and MULTIPLE_DOCS errors on unrelated files
(eth0net/zed-docker-compose#2, zed-industries/zed#12122).

Runnables for services. Each entry under services: can be started from the
gutter, offering docker compose, docker-compose, podman compose and
podman-compose. This is @lnay's work from the original extension.

A fix to the language id. The existing language_ids mapping sent
docker-compose, but the server gates every Compose feature on
dockercompose:

DockerComposeLanguage LanguageIdentifier = "dockercompose"

So Compose features would have been silently dead. It had no effect before now
because nothing defined the language for the mapping to apply to.

The grammar is registered as yaml, not docker-compose — ids must be
snake_case and match the symbol the parser exports, which for tree-sitter-yaml
is tree_sitter_yaml. Registering under any other name fails to link:

wasm-ld: error: symbol exported via --export not found: tree_sitter_docker_compose

Highlight queries are copied from Zed's YAML queries rather than shared, since
queries can't be delegated between languages.

Verification

Driven against docker-language-server v0.20.1 over stdio with the exact
initializationOptions the extension sends:

languageId	Result
dockercompose	hover with compose-spec schema docs, symbols, completion, rename
docker-compose	nothing
yaml	nothing

The grammar was compiled with Zed's bundled wasi-sdk clang both ways to confirm
the symbol constraint above. cargo build --release --target wasm32-wasip2
passes.

Notes

• No version bump — I left that to extensions::bump_version. This probably
  wants the minor label.
• Update docker-compose to v0.4.1 zed-industries/extensions#7105 should be closed rather than merged if this
  lands, otherwise both extensions would define a Docker Compose language and
  collide. Happy to close it myself once you've had a look.
• That leaves the standalone docker-compose extension redundant. It's still
  published at 0.1.0, which predates the language definition, so there's no
  collision in the meantime. I'm glad to retire it — let me know what you'd
  prefer for existing users.

Not yet covered

The server also handles Bake files (HCL), which nothing here exposes. Out of
scope for this PR, but worth noting as the remaining gap.

[Copilot]

Pull request overview

This PR adds first-class Docker Compose support to the Dockerfile Zed extension by introducing a dedicated “Docker Compose” language (scoped to Compose-specific filenames) and wiring it to docker-language-server, plus service-level runnables.

Changes:

• Add a new Docker Compose language (tree-sitter YAML grammar) with its own queries/config and filename matching.
• Add service runnables under services: with task definitions for Docker/Podman Compose variants.
• Fix docker-language-server language id mapping for Compose (dockercompose) and register the YAML grammar dependency.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
README.md	Documents added Compose language support and service runnables.
extension.toml	Adds Compose language id mapping and YAML grammar registration; updates extension description.
languages/docker-compose/config.toml	Defines the Docker Compose language metadata, suffix matching, and editor behaviors.
languages/docker-compose/highlights.scm	Provides syntax highlighting queries (copied from YAML).
languages/docker-compose/brackets.scm	Defines bracket-pair matching for the Compose language.
languages/docker-compose/outline.scm	Adds outline query for YAML/Compose mappings.
languages/docker-compose/redactions.scm	Adds redaction query for values.
languages/docker-compose/runnables.scm	Adds runnable detection for services under services:.
languages/docker-compose/tasks.json	Defines runnable task commands for Docker/Podman Compose.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[eth0net]

Both Copilot comments were fair, and chasing the first one turned up two more
problems. Fixed in a259b50.

Single-quote brackets — correct, and worth comparing against Zed's own YAML
queries, which do include the pair. Ours were derived from Zed's YAML as it stood
in early 2024 and had drifted since. Now matched, including the
rainbow.exclude directives upstream sets.

overrides.scm was missing entirely. This is the one I'm glad the first
comment led me to. It defines the string override that the
not_in = ["string"] clauses on the quote brackets refer to — without it those
clauses had nothing to resolve against, so quotes would auto-close inside
strings. Added.

increase_indent_pattern was also the 2024 version, predating Zed's fix for
comments and for the first element of an array of objects. Updated.

outline.scm now captures the value as @context as upstream does, so
outline entries show their value and not just the key.

compose run vs compose up — the task labels were accurate (docker compose run), but my README line said services could be "started", which
misdescribes it. Reworded to say it starts a one-off container rather than
bringing the service up.

On whether to add compose up <service> runnables: I've left that alone for
now, since the run tasks are @lnay's original design and I didn't want to
change intent while moving them. Happy to add up variants alongside if you
think users would expect them — it's four more entries in tasks.json.

Two things still not carried over from Zed's YAML, deliberately, and easy to add
if you'd like them: textobjects.scm and injections.scm.

[eth0net]

Added the up and down runnables in edc48e4, so each service now offers
up / run / down rather than just run.

I checked that a positional service name is actually accepted before adding
them, since a broken gutter task is worse than a missing one:

• docker compose — docker compose up [SERVICE...] and
  docker compose down [OPTIONS] [SERVICES] per the CLI reference
• docker-compose — same, via the Compose v2 standalone binary. Worth noting
  Compose v1 didn't accept services for down, but it's been EOL since 2023
• podman-compose — its argparse registers positional services for
  ["build", "up", "down", "start", "stop", "restart"], so both are covered

up is left attached rather than passing -d, so logs land in the task terminal
the way run already does. Easy to flip if you'd rather it detached.

One thing to weigh: this takes the runnable menu from 4 entries to 12, since each
of the three verbs is offered for all four tools. It's consistent, but it is a
longer list. If you'd prefer it trimmed, dropping the podman compose /
podman-compose split — or offering only docker compose and podman-compose —
would halve it.

[MrSubidubi]

Sorry for the delayed review, this looks good! Thanks!