Accept diffs that just reduce error elaboration

[RyanCavanaugh]

There are a few remaining baselines that show this behavior, but where I felt the error quality was substantially worsened by skipping the error heads:

• instanceofOperatorWithInvalidOperands.es2015
• usingDeclarations.14
• usingDeclarationsWithIteratorObject

[jakebailey]

This one is:

--- old.arrayCast.errors.txt
+++ new.arrayCast.errors.txt
@@= skipped -0, +0 lines =@@
-arrayCast.ts(3,23): error TS2352: Conversion of type '{ foo: string; }[]' to type '{ id: number; }[]' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.
-  Object literal may only specify known properties, and 'foo' does not exist in type '{ id: number; }'.
+arrayCast.ts(3,23): error TS2353: Object literal may only specify known properties, and 'foo' does not exist in type '{ id: number; }'.

It does seems like that top error provides more guidance, and with the new stack, we probably never generate it anymore?

[RyanCavanaugh]

Let's fix this by adding the error message to the list of ones we don't suppress

[jakebailey]

--- old.assignmentCompatability45.errors.txt
+++ new.assignmentCompatability45.errors.txt
@@= skipped -0, +0 lines =@@
 assignmentCompatability45.ts(7,7): error TS2322: Type 'typeof B' is not assignable to type 'typeof A'.
-  Types of construct signatures are incompatible.
-    Type 'new (x: number) => B' is not assignable to type 'abstract new () => A'.
-      Target signature provides too few arguments. Expected 1 or more, but got 0.
+  Target signature provides too few arguments. Expected 1 or more, but got 0.

It is unfortunate that we elide the whole stack, so at no point do we actually say what signature typeof B has...

[RyanCavanaugh]

Let's fix this by adding the error message ("Type of construct signatures are incompatible") to the list of ones we don't suppress

[Copilot]

Pull request overview

Updates the set of “accepted” submodule baseline diffs to allow certain diagnostic output changes where error elaboration is reduced (or error “heads” are skipped), aligning the port’s output with the current behavior while acknowledging the changed diagnostic shape.

Changes:

• Added a new “Skipped error elaboration” group to testdata/submoduleAccepted.txt and listed the affected .errors.txt.diff baselines.
• Added corresponding reference baseline diff files under testdata/baselines/reference/submoduleAccepted/{compiler,conformance}/ capturing the updated diagnostics.

Reviewed changes

Copilot reviewed 1 out of 54 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
testdata/submoduleAccepted.txt	Adds “Skipped error elaboration” accepted-baseline entries for impacted tests.
testdata/baselines/reference/submoduleAccepted/compiler/arrayCast.errors.txt.diff	Accepts updated compiler error output diff for arrayCast.
testdata/baselines/reference/submoduleAccepted/compiler/assignmentCompatWithOverloads.errors.txt.diff	Accepts updated compiler error output diff for assignmentCompatWithOverloads.
testdata/baselines/reference/submoduleAccepted/compiler/assignmentCompatability44.errors.txt.diff	Accepts updated compiler error output diff for assignmentCompatability44.
testdata/baselines/reference/submoduleAccepted/compiler/assignmentCompatability45.errors.txt.diff	Accepts updated compiler error output diff for assignmentCompatability45.
testdata/baselines/reference/submoduleAccepted/compiler/assignmentCompatability_checking-apply-member-off-of-function-interface.errors.txt.diff	Accepts updated compiler error output diff for apply-member checking.
testdata/baselines/reference/submoduleAccepted/compiler/assignmentCompatability_checking-call-member-off-of-function-interface.errors.txt.diff	Accepts updated compiler error output diff for call-member checking.
testdata/baselines/reference/submoduleAccepted/compiler/bigintWithLib.errors.txt.diff	Accepts updated compiler error output diff for bigintWithLib.
testdata/baselines/reference/submoduleAccepted/compiler/classSideInheritance3.errors.txt.diff	Accepts updated compiler error output diff for classSideInheritance3.
testdata/baselines/reference/submoduleAccepted/compiler/computedPropertyBindingElementDeclarationNoCrash1.errors.txt.diff	Accepts updated compiler error output diff for computed-property binding element case.
testdata/baselines/reference/submoduleAccepted/compiler/constraints0.errors.txt.diff	Accepts updated compiler error output diff for constraints0.
testdata/baselines/reference/submoduleAccepted/compiler/differentTypesWithSameName.errors.txt.diff	Accepts updated compiler error output diff for differentTypesWithSameName.
testdata/baselines/reference/submoduleAccepted/compiler/excessPropertyCheckWithUnions.errors.txt.diff	Accepts updated compiler error output diff for excessPropertyCheckWithUnions.
testdata/baselines/reference/submoduleAccepted/compiler/genericConstraint2.errors.txt.diff	Accepts updated compiler error output diff for genericConstraint2.
testdata/baselines/reference/submoduleAccepted/compiler/genericTypeConstraints.errors.txt.diff	Accepts updated compiler error output diff for genericTypeConstraints.
testdata/baselines/reference/submoduleAccepted/compiler/generics1.errors.txt.diff	Accepts updated compiler error output diff for generics1.
testdata/baselines/reference/submoduleAccepted/compiler/generics2.errors.txt.diff	Accepts updated compiler error output diff for generics2.
testdata/baselines/reference/submoduleAccepted/compiler/generics5.errors.txt.diff	Accepts updated compiler error output diff for generics5.
testdata/baselines/reference/submoduleAccepted/compiler/inferenceFromIncompleteSource.errors.txt.diff	Accepts updated compiler error output diff for inferenceFromIncompleteSource.
testdata/baselines/reference/submoduleAccepted/compiler/mappedTypeAsStringTemplate.errors.txt.diff	Accepts updated compiler error output diff for mappedTypeAsStringTemplate.
testdata/baselines/reference/submoduleAccepted/compiler/noParameterReassignmentJSIIFE.errors.txt.diff	Accepts updated compiler error output diff for noParameterReassignmentJSIIFE.
testdata/baselines/reference/submoduleAccepted/compiler/objectLiteralFunctionArgContextualTyping2.errors.txt.diff	Accepts updated compiler error output diff for contextual typing case.
testdata/baselines/reference/submoduleAccepted/compiler/objectLiteralThisWidenedOnUse.errors.txt.diff	Accepts updated compiler error output diff for objectLiteralThisWidenedOnUse.
testdata/baselines/reference/submoduleAccepted/compiler/recursiveClassReferenceTest.errors.txt.diff	Accepts updated compiler error output diff for recursiveClassReferenceTest.
testdata/baselines/reference/submoduleAccepted/compiler/templateStringsArrayTypeDefinedInES5Mode(target=es2015).errors.txt.diff	Accepts updated compiler error output diff for template strings array type (defined).
testdata/baselines/reference/submoduleAccepted/compiler/templateStringsArrayTypeNotDefinedES5Mode(target=es2015).errors.txt.diff	Accepts updated compiler error output diff for template strings array type (not defined).
testdata/baselines/reference/submoduleAccepted/compiler/templateStringsArrayTypeRedefinedInES6Mode.errors.txt.diff	Accepts updated compiler error output diff for template strings array type (redefined).
testdata/baselines/reference/submoduleAccepted/compiler/typeArgumentInferenceWithConstraintAsCommonRoot.errors.txt.diff	Accepts updated compiler error output diff for constraint/common-root inference.
testdata/baselines/reference/submoduleAccepted/conformance/decoratorOnClassMethod10(target=es2015).errors.txt.diff	Accepts updated conformance error output diff for decorator method case.
testdata/baselines/reference/submoduleAccepted/conformance/destructuringParameterDeclaration2.errors.txt.diff	Accepts updated conformance error output diff for destructuring parameter case (2).
testdata/baselines/reference/submoduleAccepted/conformance/destructuringParameterDeclaration5.errors.txt.diff	Accepts updated conformance error output diff for destructuring parameter case (5).
testdata/baselines/reference/submoduleAccepted/conformance/es2020IntlAPIs.errors.txt.diff	Accepts updated conformance error output diff for ES2020 Intl APIs.
testdata/baselines/reference/submoduleAccepted/conformance/genericCallWithObjectTypeArgsAndConstraints4.errors.txt.diff	Accepts updated conformance error output diff for generic call constraints (4).
testdata/baselines/reference/submoduleAccepted/conformance/genericCallWithObjectTypeArgsAndConstraints5.errors.txt.diff	Accepts updated conformance error output diff for generic call constraints (5).
testdata/baselines/reference/submoduleAccepted/conformance/iterableArrayPattern17.errors.txt.diff	Accepts updated conformance error output diff for iterable array pattern (17).
testdata/baselines/reference/submoduleAccepted/conformance/iterableArrayPattern18.errors.txt.diff	Accepts updated conformance error output diff for iterable array pattern (18).
testdata/baselines/reference/submoduleAccepted/conformance/iterableArrayPattern19.errors.txt.diff	Accepts updated conformance error output diff for iterable array pattern (19).
testdata/baselines/reference/submoduleAccepted/conformance/mappedTypeConstraints2.errors.txt.diff	Accepts updated conformance error output diff for mapped type constraints (2).
testdata/baselines/reference/submoduleAccepted/conformance/narrowingGenericTypeFromInstanceof01.errors.txt.diff	Accepts updated conformance error output diff for generic narrowing via instanceof.
testdata/baselines/reference/submoduleAccepted/conformance/noInfer.errors.txt.diff	Accepts updated conformance error output diff for noInfer.
testdata/baselines/reference/submoduleAccepted/conformance/objectLiteralShorthandPropertiesFunctionArgument2.errors.txt.diff	Accepts updated conformance error output diff for object literal shorthand arg case.
testdata/baselines/reference/submoduleAccepted/conformance/subtypingWithNumericIndexer2.errors.txt.diff	Accepts updated conformance error output diff for numeric indexer subtyping (2).
testdata/baselines/reference/submoduleAccepted/conformance/subtypingWithNumericIndexer3.errors.txt.diff	Accepts updated conformance error output diff for numeric indexer subtyping (3).
testdata/baselines/reference/submoduleAccepted/conformance/subtypingWithNumericIndexer4.errors.txt.diff	Accepts updated conformance error output diff for numeric indexer subtyping (4).
testdata/baselines/reference/submoduleAccepted/conformance/subtypingWithNumericIndexer5.errors.txt.diff	Accepts updated conformance error output diff for numeric indexer subtyping (5).
testdata/baselines/reference/submoduleAccepted/conformance/subtypingWithStringIndexer2.errors.txt.diff	Accepts updated conformance error output diff for string indexer subtyping (2).
testdata/baselines/reference/submoduleAccepted/conformance/subtypingWithStringIndexer3.errors.txt.diff	Accepts updated conformance error output diff for string indexer subtyping (3).
testdata/baselines/reference/submoduleAccepted/conformance/subtypingWithStringIndexer4.errors.txt.diff	Accepts updated conformance error output diff for string indexer subtyping (4).
testdata/baselines/reference/submoduleAccepted/conformance/thisTypeInFunctionsNegative.errors.txt.diff	Accepts updated conformance error output diff for negative this typing in functions.
testdata/baselines/reference/submoduleAccepted/conformance/typeSatisfaction.errors.txt.diff	Accepts updated conformance error output diff for satisfies type satisfaction.
testdata/baselines/reference/submoduleAccepted/conformance/typeSatisfactionWithDefaultExport.errors.txt.diff	Accepts updated conformance error output diff for satisfies + default export.
testdata/baselines/reference/submoduleAccepted/conformance/typeSatisfaction_errorLocations1.errors.txt.diff	Accepts updated conformance error output diff for satisfies error locations.
testdata/baselines/reference/submoduleAccepted/conformance/typedefMultipleTypeParameters.errors.txt.diff	Accepts updated conformance error output diff for typedef multiple type params.
testdata/baselines/reference/submoduleAccepted/conformance/unionTypeCallSignatures6.errors.txt.diff	Accepts updated conformance error output diff for union call signatures case.

Comments suppressed due to low confidence (1)

testdata/submoduleAccepted.txt:117

• These accepted baseline entries don't have corresponding files under testdata/baselines/reference/submoduleAccepted/conformance/. Both usingDeclarations.14.errors.txt.diff and usingDeclarationsWithIteratorObject.errors.txt.diff are listed here but the diff files are missing, which will cause the accepted baseline list to reference non-existent baselines. Add the missing .errors.txt.diff files or remove/correct these entries.

[Copilot]

These accepted baseline entries don't have corresponding files under testdata/baselines/reference/submoduleAccepted/conformance/. Currently instanceofOperatorWithInvalidOperands.es2015.errors.txt.diff is listed here but the diff file is missing, so the submoduleAccepted baseline set will reference a non-existent baseline. Add the missing .errors.txt.diff file(s) or remove/correct this entry.

This issue also appears on line 116 of the same file.

[jakebailey]

     declare var e: Elephant;
     f(g, e); // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
          ~
-!!! error TS2345: Argument of type 'Elephant' is not assignable to parameter of type 'Giraffe'.
-!!! error TS2345:   Property 'y' is missing in type 'Elephant' but required in type 'Giraffe'.
+!!! error TS2741: Property 'y' is missing in type 'Elephant' but required in type 'Giraffe'.
 !!! related TS2728 typeArgumentInferenceWithConstraintAsCommonRoot.ts:2:36: 'y' is declared here.

Not mega thrilled we don't clearly identify which type is the arg and which is the parameter...

[RyanCavanaugh]

Let's raise this in a meeting and accept for now

[jakebailey]

--- old.constraints0.errors.txt
+++ new.constraints0.errors.txt
@@= skipped -0, +0 lines =@@
-constraints0.ts(14,19): error TS2344: Type 'B' does not satisfy the constraint 'A'.
-  Property 'a' is missing in type 'B' but required in type 'A'.
+constraints0.ts(14,19): error TS2741: Property 'a' is missing in type 'B' but required in type 'A'.

This is one of those things I think there was disagreement about. I think it's a bummer to lose the word "constraint" here, but...

[RyanCavanaugh]

Let's raise this in a meeting and accept for now