Deduplicate repeated declarations on union/intersection properties#4600
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Andarist wants to merge 3 commits into
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Deduplicate repeated declarations on union/intersection properties#4600Andarist wants to merge 3 commits into
Andarist wants to merge 3 commits into
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Andarist
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Jul 10, 2026
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a detailed writeup about what happens in this repro can be found here: microsoft/TypeScript#63119
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Pull request overview
This PR addresses microsoft/TypeScript#63560 by deduplicating repeated Symbol.Declarations when constructing union/intersection properties, reducing declaration blow-ups (OOM/crash risk) and making symbol baselines deterministic.
Changes:
- Deduplicate
prop.Declarationswhile synthesizing union/intersection properties in the checker. - Add new compiler regression tests covering intersection-constructor reduction and a large union/intersection cross-product scenario.
- Update numerous
.symbols/.symbols.diffbaselines to reflect the new (deduplicated) declaration lists.
Reviewed changes
Copilot reviewed 58 out of 60 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| internal/checker/checker.go | Deduplicates declaration lists while building union/intersection properties. |
| testdata/tests/cases/compiler/intersectionConstructorReductionCrash.ts | New regression test for intersection-constructor reduction crash scenario. |
| testdata/baselines/reference/compiler/intersectionConstructorReductionCrash.symbols | Baseline updates for the new intersection-constructor regression test. |
| testdata/baselines/reference/compiler/intersectionConstructorReductionCrash.types | Baseline updates for the new intersection-constructor regression test. |
| testdata/tests/cases/compiler/crossProductUnionIntersectionRepeatedPropDeclarationsNoOOM1.ts | New regression test exercising large union/intersection cross-product behavior. |
| testdata/baselines/reference/compiler/crossProductUnionIntersectionRepeatedPropDeclarationsNoOOM1.symbols | New symbols baseline for the cross-product regression test. |
| testdata/baselines/reference/compiler/crossProductUnionIntersectionRepeatedPropDeclarationsNoOOM1.types | New types baseline for the cross-product regression test. |
| testdata/baselines/reference/compiler/crossProductUnionIntersectionRepeatedPropDeclarationsNoOOM1.errors.txt | New error baseline for the cross-product regression test. |
| testdata/baselines/reference/submodule/conformance/typedefCrossModule2.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/typedefCrossModule2.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/objectLiteralNormalization.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/objectLiteralNormalization.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/mixinAccessModifiers.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/mixinAccessModifiers.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/intersectionOfUnionNarrowing.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/intersectionOfUnionNarrowing.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/bivariantInferences.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/conformance/bivariantInferences.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/unionOfClassCalls.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/unionOfClassCalls.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/unionOfArraysFilterCall.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/unionOfArraysFilterCall.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/unionCallMixedTypeParameterPresence.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/unionCallMixedTypeParameterPresence.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeVariableConstraintIntersections.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeVariableConstraintIntersections.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeParameterLeak.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeParameterLeak.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeParameterExtendingUnion2.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeParameterExtendingUnion2.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeParameterExtendingUnion1.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/typeParameterExtendingUnion1.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/sliceResultCast.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/sliceResultCast.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/silentNeverPropagation.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/silentNeverPropagation.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/recursiveArrayNotCircular.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/recursiveArrayNotCircular.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/neverAsDiscriminantType(strict=true).symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/neverAsDiscriminantType(strict=true).symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/neverAsDiscriminantType(strict=false).symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/neverAsDiscriminantType(strict=false).symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/discriminateWithOptionalProperty4(exactoptionalpropertytypes=true).symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/discriminateWithOptionalProperty4(exactoptionalpropertytypes=true).symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/discriminateWithOptionalProperty4(exactoptionalpropertytypes=false).symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/discriminateWithOptionalProperty4(exactoptionalpropertytypes=false).symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/controlFlowArrayErrors.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/controlFlowArrayErrors.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/contextualOverloadListFromArrayUnion.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/contextualOverloadListFromArrayUnion.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/callsOnComplexSignatures.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/callsOnComplexSignatures.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/bestChoiceType.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/bestChoiceType.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/arraySlice.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/arraySlice.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/arrayDestructuringInSwitch1.symbols.diff | Baseline diffs updated to remove duplicate declaration entries. |
| testdata/baselines/reference/submodule/compiler/arrayDestructuringInSwitch1.symbols | Baseline updated to remove duplicate declaration entries. |
| testdata/baselines/reference/compiler/nestedSpreadsAndWidening.symbols | Baseline updated to reflect deduplicated declarations. |
| testdata/baselines/reference/compiler/multipleModuleExportsAssignments.symbols | Baseline updated to reflect deduplicated declarations. |
Comment on lines
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| for _, declaration := range prop.Declarations { | ||
| declarations = core.AppendIfUnique(declarations, declaration) | ||
| } |
Comment on lines
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+431
| export function createShapeAtNearestAdjacentEmptyPosition< | ||
| N extends ShapeWithDimensions<TLShape>, | ||
| >({ | ||
| newShape: newShapePartial, | ||
| }: { | ||
| newShape: ShapePartialWithDimensions<N>; | ||
| }): { | ||
| newShape: N; | ||
| } { | ||
| newShapePartial.props?.w; | ||
| } |
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closes microsoft/TypeScript#63560