diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts index e737cd58bd560..523af078c0196 100644 --- a/src/compiler/checker.ts +++ b/src/compiler/checker.ts @@ -5073,9 +5073,6 @@ namespace ts { } return objectTypeRelatedTo(source, source, target, /*reportErrors*/ false); } - if (source.flags & TypeFlags.TypeParameter && target.flags & TypeFlags.TypeParameter) { - return typeParameterIdenticalTo(source, target); - } if (source.flags & TypeFlags.Union && target.flags & TypeFlags.Union || source.flags & TypeFlags.Intersection && target.flags & TypeFlags.Intersection) { if (result = eachTypeRelatedToSomeType(source, target)) { @@ -5206,17 +5203,6 @@ namespace ts { return result; } - function typeParameterIdenticalTo(source: TypeParameter, target: TypeParameter): Ternary { - // covers case when both type parameters does not have constraint (both equal to noConstraintType) - if (source.constraint === target.constraint) { - return Ternary.True; - } - if (source.constraint === noConstraintType || target.constraint === noConstraintType) { - return Ternary.False; - } - return isIdenticalTo(source.constraint, target.constraint); - } - // Determine if two object types are related by structure. First, check if the result is already available in the global cache. // Second, check if we have already started a comparison of the given two types in which case we assume the result to be true. // Third, check if both types are part of deeply nested chains of generic type instantiations and if so assume the types are @@ -5765,26 +5751,19 @@ namespace ts { if (!(isMatchingSignature(source, target, partialMatch))) { return Ternary.False; } - let result = Ternary.True; - if (source.typeParameters && target.typeParameters) { - if (source.typeParameters.length !== target.typeParameters.length) { - return Ternary.False; - } - for (let i = 0, len = source.typeParameters.length; i < len; ++i) { - const related = compareTypes(source.typeParameters[i], target.typeParameters[i]); - if (!related) { - return Ternary.False; - } - result &= related; - } - } - else if (source.typeParameters || target.typeParameters) { + // Check that the two signatures have the same number of type parameters. We might consider + // also checking that any type parameter constraints match, but that would require instantiating + // the constraints with a common set of type arguments to get relatable entities in places where + // type parameters occur in the constraints. The complexity of doing that doesn't seem worthwhile, + // particularly as we're comparing erased versions of the signatures below. + if ((source.typeParameters ? source.typeParameters.length : 0) !== (target.typeParameters ? target.typeParameters.length : 0)) { return Ternary.False; } // Spec 1.0 Section 3.8.3 & 3.8.4: // M and N (the signatures) are instantiated using type Any as the type argument for all type parameters declared by M and N source = getErasedSignature(source); target = getErasedSignature(target); + let result = Ternary.True; const targetLen = target.parameters.length; for (let i = 0; i < targetLen; i++) { const s = isRestParameterIndex(source, i) ? getRestTypeOfSignature(source) : getTypeOfSymbol(source.parameters[i]); diff --git a/tests/baselines/reference/genericSignatureIdentity.js b/tests/baselines/reference/genericSignatureIdentity.js new file mode 100644 index 0000000000000..9a51a61edbd53 --- /dev/null +++ b/tests/baselines/reference/genericSignatureIdentity.js @@ -0,0 +1,32 @@ +//// [genericSignatureIdentity.ts] +// This test is here to remind us of our current limits of type identity checking. +// Ideally all of the below declarations would be considered different (and thus errors) +// but they aren't because we erase type parameters to type any and don't check that +// constraints are identical. + +var x: { + (x: T): T; +}; + +var x: { + (x: T): T; +}; + +var x: { + (x: T): T; +}; + +var x: { + (x: any): any; +}; + + +//// [genericSignatureIdentity.js] +// This test is here to remind us of our current limits of type identity checking. +// Ideally all of the below declarations would be considered different (and thus errors) +// but they aren't because we erase type parameters to type any and don't check that +// constraints are identical. +var x; +var x; +var x; +var x; diff --git a/tests/baselines/reference/genericSignatureIdentity.symbols b/tests/baselines/reference/genericSignatureIdentity.symbols new file mode 100644 index 0000000000000..afd12ec266a18 --- /dev/null +++ b/tests/baselines/reference/genericSignatureIdentity.symbols @@ -0,0 +1,49 @@ +=== tests/cases/compiler/genericSignatureIdentity.ts === +// This test is here to remind us of our current limits of type identity checking. +// Ideally all of the below declarations would be considered different (and thus errors) +// but they aren't because we erase type parameters to type any and don't check that +// constraints are identical. + +var x: { +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 5, 3), Decl(genericSignatureIdentity.ts, 9, 3), Decl(genericSignatureIdentity.ts, 13, 3), Decl(genericSignatureIdentity.ts, 17, 3)) + + (x: T): T; +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 6, 5)) +>Date : Symbol(Date, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --)) +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 6, 21)) +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 6, 5)) +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 6, 5)) + +}; + +var x: { +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 5, 3), Decl(genericSignatureIdentity.ts, 9, 3), Decl(genericSignatureIdentity.ts, 13, 3), Decl(genericSignatureIdentity.ts, 17, 3)) + + (x: T): T; +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 10, 5)) +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 10, 23)) +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 10, 5)) +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 10, 5)) + +}; + +var x: { +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 5, 3), Decl(genericSignatureIdentity.ts, 9, 3), Decl(genericSignatureIdentity.ts, 13, 3), Decl(genericSignatureIdentity.ts, 17, 3)) + + (x: T): T; +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 14, 5)) +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 14, 8)) +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 14, 5)) +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 14, 5)) + +}; + +var x: { +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 5, 3), Decl(genericSignatureIdentity.ts, 9, 3), Decl(genericSignatureIdentity.ts, 13, 3), Decl(genericSignatureIdentity.ts, 17, 3)) + + (x: any): any; +>T : Symbol(T, Decl(genericSignatureIdentity.ts, 18, 5)) +>x : Symbol(x, Decl(genericSignatureIdentity.ts, 18, 8)) + +}; + diff --git a/tests/baselines/reference/genericSignatureIdentity.types b/tests/baselines/reference/genericSignatureIdentity.types new file mode 100644 index 0000000000000..9385718a36127 --- /dev/null +++ b/tests/baselines/reference/genericSignatureIdentity.types @@ -0,0 +1,49 @@ +=== tests/cases/compiler/genericSignatureIdentity.ts === +// This test is here to remind us of our current limits of type identity checking. +// Ideally all of the below declarations would be considered different (and thus errors) +// but they aren't because we erase type parameters to type any and don't check that +// constraints are identical. + +var x: { +>x : (x: T) => T + + (x: T): T; +>T : T +>Date : Date +>x : T +>T : T +>T : T + +}; + +var x: { +>x : (x: T) => T + + (x: T): T; +>T : T +>x : T +>T : T +>T : T + +}; + +var x: { +>x : (x: T) => T + + (x: T): T; +>T : T +>x : T +>T : T +>T : T + +}; + +var x: { +>x : (x: T) => T + + (x: any): any; +>T : T +>x : any + +}; + diff --git a/tests/baselines/reference/unionTypeParameterInference.js b/tests/baselines/reference/unionTypeParameterInference.js new file mode 100644 index 0000000000000..c96e809cd4dc8 --- /dev/null +++ b/tests/baselines/reference/unionTypeParameterInference.js @@ -0,0 +1,17 @@ +//// [unionTypeParameterInference.ts] +// Regression test for #5861 + +interface Foo { prop: T; } + +declare function lift(value: U | Foo): Foo; + +function unlift(value: U | Foo): U { + return lift(value).prop; +} + + +//// [unionTypeParameterInference.js] +// Regression test for #5861 +function unlift(value) { + return lift(value).prop; +} diff --git a/tests/baselines/reference/unionTypeParameterInference.symbols b/tests/baselines/reference/unionTypeParameterInference.symbols new file mode 100644 index 0000000000000..f2dbaac31ffb5 --- /dev/null +++ b/tests/baselines/reference/unionTypeParameterInference.symbols @@ -0,0 +1,35 @@ +=== tests/cases/compiler/unionTypeParameterInference.ts === +// Regression test for #5861 + +interface Foo { prop: T; } +>Foo : Symbol(Foo, Decl(unionTypeParameterInference.ts, 0, 0)) +>T : Symbol(T, Decl(unionTypeParameterInference.ts, 2, 14)) +>prop : Symbol(prop, Decl(unionTypeParameterInference.ts, 2, 18)) +>T : Symbol(T, Decl(unionTypeParameterInference.ts, 2, 14)) + +declare function lift(value: U | Foo): Foo; +>lift : Symbol(lift, Decl(unionTypeParameterInference.ts, 2, 29)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 4, 22)) +>value : Symbol(value, Decl(unionTypeParameterInference.ts, 4, 25)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 4, 22)) +>Foo : Symbol(Foo, Decl(unionTypeParameterInference.ts, 0, 0)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 4, 22)) +>Foo : Symbol(Foo, Decl(unionTypeParameterInference.ts, 0, 0)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 4, 22)) + +function unlift(value: U | Foo): U { +>unlift : Symbol(unlift, Decl(unionTypeParameterInference.ts, 4, 52)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 6, 16)) +>value : Symbol(value, Decl(unionTypeParameterInference.ts, 6, 19)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 6, 16)) +>Foo : Symbol(Foo, Decl(unionTypeParameterInference.ts, 0, 0)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 6, 16)) +>U : Symbol(U, Decl(unionTypeParameterInference.ts, 6, 16)) + + return lift(value).prop; +>lift(value).prop : Symbol(Foo.prop, Decl(unionTypeParameterInference.ts, 2, 18)) +>lift : Symbol(lift, Decl(unionTypeParameterInference.ts, 2, 29)) +>value : Symbol(value, Decl(unionTypeParameterInference.ts, 6, 19)) +>prop : Symbol(Foo.prop, Decl(unionTypeParameterInference.ts, 2, 18)) +} + diff --git a/tests/baselines/reference/unionTypeParameterInference.types b/tests/baselines/reference/unionTypeParameterInference.types new file mode 100644 index 0000000000000..54eaed90ecc42 --- /dev/null +++ b/tests/baselines/reference/unionTypeParameterInference.types @@ -0,0 +1,36 @@ +=== tests/cases/compiler/unionTypeParameterInference.ts === +// Regression test for #5861 + +interface Foo { prop: T; } +>Foo : Foo +>T : T +>prop : T +>T : T + +declare function lift(value: U | Foo): Foo; +>lift : (value: U | Foo) => Foo +>U : U +>value : U | Foo +>U : U +>Foo : Foo +>U : U +>Foo : Foo +>U : U + +function unlift(value: U | Foo): U { +>unlift : (value: U | Foo) => U +>U : U +>value : U | Foo +>U : U +>Foo : Foo +>U : U +>U : U + + return lift(value).prop; +>lift(value).prop : U +>lift(value) : Foo +>lift : (value: U | Foo) => Foo +>value : U | Foo +>prop : U +} + diff --git a/tests/cases/compiler/genericSignatureIdentity.ts b/tests/cases/compiler/genericSignatureIdentity.ts new file mode 100644 index 0000000000000..c685b8cc57363 --- /dev/null +++ b/tests/cases/compiler/genericSignatureIdentity.ts @@ -0,0 +1,20 @@ +// This test is here to remind us of our current limits of type identity checking. +// Ideally all of the below declarations would be considered different (and thus errors) +// but they aren't because we erase type parameters to type any and don't check that +// constraints are identical. + +var x: { + (x: T): T; +}; + +var x: { + (x: T): T; +}; + +var x: { + (x: T): T; +}; + +var x: { + (x: any): any; +}; diff --git a/tests/cases/compiler/unionTypeParameterInference.ts b/tests/cases/compiler/unionTypeParameterInference.ts new file mode 100644 index 0000000000000..79c4f3cc0e52a --- /dev/null +++ b/tests/cases/compiler/unionTypeParameterInference.ts @@ -0,0 +1,9 @@ +// Regression test for #5861 + +interface Foo { prop: T; } + +declare function lift(value: U | Foo): Foo; + +function unlift(value: U | Foo): U { + return lift(value).prop; +}