Add laziness test suite for type checking dependencies (#3219)#3219
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Add laziness test suite for type checking dependencies (#3219)#3219samwgoldman wants to merge 1 commit intomainfrom
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Summary:
Adds a snapshot-based test suite documenting how much of a file's dependencies get type-checked when the file itself is checked. The laziness goal is that dependencies should stop at the earliest step (Load/Ast/Exports/Answers/Solutions) sufficient to resolve what callers actually need — e.g. a transitively-imported module used only as an annotation should not have its body inferred.
Each test sets up a small module graph, checks one entry-point module, and records in a markdown snapshot the highest step each module reached plus the tree of cross-module demands observed. The snapshots capture current behavior — some document good laziness properties, others document opportunities where dependencies are computed further than callers need. Snapshots regenerate with `UPDATE_SNAPSHOTS=1`.
Supporting infrastructure:
- `DemandCollector` (`pyrefly_util::demand_tree`) records cross-module `LookupExport`/`LookupAnswer` events into a tree. Scoped to a single `Transaction` via `set_demand_collector` so parallel checks don't interfere. `enter()` returns an RAII span guard so the per-thread nesting stack stays balanced even when an Answer lookup panics.
- `pyrefly check --report-demand-tree <path>` emits a JSON document (`{ module_steps, demand_tree }`).
- The test harness renders the structured tree into a flat indented form for snapshot comparison, and aggregates pervasive `builtins`/`typing` demands into a single count so test output stays readable.
Differential Revision: D102239243
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Summary:
Adds a snapshot-based test suite documenting how much of a file's dependencies get type-checked when the file itself is checked. The laziness goal is that dependencies should stop at the earliest step (Load/Ast/Exports/Answers/Solutions) sufficient to resolve what callers actually need — e.g. a transitively-imported module used only as an annotation should not have its body inferred.
Each test sets up a small module graph, checks one entry-point module, and records in a markdown snapshot the highest step each module reached plus the tree of cross-module demands observed. The snapshots capture current behavior — some document good laziness properties, others document opportunities where dependencies are computed further than callers need. Snapshots regenerate with `UPDATE_SNAPSHOTS=1`.
Supporting infrastructure:
- `DemandCollector` (`pyrefly_util::demand_tree`) records cross-module `LookupExport`/`LookupAnswer` events into a tree. Scoped to a single `Transaction` via `set_demand_collector` so parallel checks don't interfere. `enter()` returns an RAII span guard so the per-thread nesting stack stays balanced even when an Answer lookup panics.
- `pyrefly check --report-demand-tree <path>` emits a JSON document (`{ module_steps, demand_tree }`).
- The test harness renders the structured tree into a flat indented form for snapshot comparison, and aggregates pervasive `builtins`/`typing` demands into a single count so test output stays readable.
Differential Revision: D102239243
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Summary: Pull Request resolved: #3219 Adds a snapshot-based test suite documenting how much of a file's dependencies get type-checked when the file itself is checked. The laziness goal is that dependencies should stop at the earliest step (Load/Ast/Exports/Answers/Solutions) sufficient to resolve what callers actually need — e.g. a transitively-imported module used only as an annotation should not have its body inferred. Each test sets up a small module graph, checks one entry-point module, and records in a markdown snapshot the highest step each module reached plus the tree of cross-module demands observed. The snapshots capture current behavior — some document good laziness properties, others document opportunities where dependencies are computed further than callers need. Snapshots regenerate with `UPDATE_SNAPSHOTS=1`. Supporting infrastructure: - `DemandCollector` (`pyrefly_util::demand_tree`) records cross-module `LookupExport`/`LookupAnswer` events into a tree. Scoped to a single `Transaction` via `set_demand_collector` so parallel checks don't interfere. `enter()` returns an RAII span guard so the per-thread nesting stack stays balanced even when an Answer lookup panics. - `pyrefly check --report-demand-tree <path>` emits a JSON document (`{ module_steps, demand_tree }`). - The test harness renders the structured tree into a flat indented form for snapshot comparison, and aggregates pervasive `builtins`/`typing` demands into a single count so test output stays readable. Differential Revision: D102239243
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According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅ |
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Summary:
Adds a snapshot-based test suite documenting how much of a file's dependencies get type-checked when the file itself is checked. The laziness goal is that dependencies should stop at the earliest step (Load/Ast/Exports/Answers/Solutions) sufficient to resolve what callers actually need — e.g. a transitively-imported module used only as an annotation should not have its body inferred.
Each test sets up a small module graph, checks one entry-point module, and records in a markdown snapshot the highest step each module reached plus the tree of cross-module demands observed. The snapshots capture current behavior — some document good laziness properties, others document opportunities where dependencies are computed further than callers need. Snapshots regenerate with
UPDATE_SNAPSHOTS=1.Supporting infrastructure:
DemandCollector(pyrefly_util::demand_tree) records cross-moduleLookupExport/LookupAnswerevents into a tree. Scoped to a singleTransactionviaset_demand_collectorso parallel checks don't interfere.enter()returns an RAII span guard so the per-thread nesting stack stays balanced even when an Answer lookup panics.pyrefly check --report-demand-tree <path>emits a JSON document ({ module_steps, demand_tree }).builtins/typingdemands into a single count so test output stays readable.Differential Revision: D102239243