diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts index a1340db32c2ed..5b7f4988b3bf2 100644 --- a/src/compiler/checker.ts +++ b/src/compiler/checker.ts @@ -7335,27 +7335,29 @@ namespace ts { } function containsMatchingReference(source: Node, target: Node) { - while (true) { + while (source.kind === SyntaxKind.PropertyAccessExpression) { + source = (source).expression; if (isMatchingReference(source, target)) { return true; } - if (source.kind !== SyntaxKind.PropertyAccessExpression) { - return false; - } - source = (source).expression; } + return false; + } + + function isOrContainsMatchingReference(source: Node, target: Node) { + return isMatchingReference(source, target) || containsMatchingReference(source, target); } - function hasMatchingArgument(callExpression: CallExpression, target: Node) { + function hasMatchingArgument(callExpression: CallExpression, reference: Node) { if (callExpression.arguments) { for (const argument of callExpression.arguments) { - if (isMatchingReference(argument, target)) { + if (isOrContainsMatchingReference(reference, argument)) { return true; } } } if (callExpression.expression.kind === SyntaxKind.PropertyAccessExpression && - isMatchingReference((callExpression.expression).expression, target)) { + isOrContainsMatchingReference(reference, (callExpression.expression).expression)) { return true; } return false; @@ -7618,8 +7620,7 @@ namespace ts { // may be an assignment to a left hand part of the reference. For example, for a // reference 'x.y.z', we may be at an assignment to 'x.y' or 'x'. In that case, // return the declared type. - if (reference.kind === SyntaxKind.PropertyAccessExpression && - containsMatchingReference((reference).expression, node)) { + if (containsMatchingReference(reference, node)) { return declaredType; } // Assignment doesn't affect reference @@ -7682,7 +7683,7 @@ namespace ts { } function narrowTypeByTruthiness(type: Type, expr: Expression, assumeTrue: boolean): Type { - return isMatchingReference(expr, reference) ? getTypeWithFacts(type, assumeTrue ? TypeFacts.Truthy : TypeFacts.Falsy) : type; + return isMatchingReference(reference, expr) ? getTypeWithFacts(type, assumeTrue ? TypeFacts.Truthy : TypeFacts.Falsy) : type; } function narrowTypeByBinaryExpression(type: Type, expr: BinaryExpression, assumeTrue: boolean): Type { @@ -7714,7 +7715,7 @@ namespace ts { if (operator === SyntaxKind.ExclamationEqualsToken || operator === SyntaxKind.ExclamationEqualsEqualsToken) { assumeTrue = !assumeTrue; } - if (!strictNullChecks || !isMatchingReference(expr.left, reference)) { + if (!strictNullChecks || !isMatchingReference(reference, expr.left)) { return type; } const doubleEquals = operator === SyntaxKind.EqualsEqualsToken || operator === SyntaxKind.ExclamationEqualsToken; @@ -7731,7 +7732,12 @@ namespace ts { // and string literal on the right const left = expr.left; const right = expr.right; - if (!isMatchingReference(left.expression, reference)) { + if (!isMatchingReference(reference, left.expression)) { + // For a reference of the form 'x.y', a 'typeof x === ...' type guard resets the + // narrowed type of 'y' to its declared type. + if (containsMatchingReference(reference, left.expression)) { + return declaredType; + } return type; } if (expr.operatorToken.kind === SyntaxKind.ExclamationEqualsToken || @@ -7754,8 +7760,16 @@ namespace ts { } function narrowTypeByInstanceof(type: Type, expr: BinaryExpression, assumeTrue: boolean): Type { - // Check that type is not any, assumed result is true, and we have variable symbol on the left - if (isTypeAny(type) || !isMatchingReference(expr.left, reference)) { + if (!isMatchingReference(reference, expr.left)) { + // For a reference of the form 'x.y', an 'x instanceof T' type guard resets the + // narrowed type of 'y' to its declared type. + if (containsMatchingReference(reference, expr.left)) { + return declaredType; + } + return type; + } + // We never narrow type any in an instanceof guard + if (isTypeAny(type)) { return type; } @@ -7830,18 +7844,26 @@ namespace ts { } if (isIdentifierTypePredicate(predicate)) { const predicateArgument = callExpression.arguments[predicate.parameterIndex]; - if (predicateArgument && isMatchingReference(predicateArgument, reference)) { - return getNarrowedType(type, predicate.type, assumeTrue); + if (predicateArgument) { + if (isMatchingReference(reference, predicateArgument)) { + return getNarrowedType(type, predicate.type, assumeTrue); + } + if (containsMatchingReference(reference, predicateArgument)) { + return declaredType; + } } } else { const invokedExpression = skipParenthesizedNodes(callExpression.expression); if (invokedExpression.kind === SyntaxKind.ElementAccessExpression || invokedExpression.kind === SyntaxKind.PropertyAccessExpression) { const accessExpression = invokedExpression as ElementAccessExpression | PropertyAccessExpression; - const possibleReference= skipParenthesizedNodes(accessExpression.expression); - if (isMatchingReference(possibleReference, reference)) { + const possibleReference = skipParenthesizedNodes(accessExpression.expression); + if (isMatchingReference(reference, possibleReference)) { return getNarrowedType(type, predicate.type, assumeTrue); } + if (containsMatchingReference(reference, possibleReference)) { + return declaredType; + } } } return type; diff --git a/tests/baselines/reference/narrowingOfDottedNames.js b/tests/baselines/reference/narrowingOfDottedNames.js new file mode 100644 index 0000000000000..14cdcd5563190 --- /dev/null +++ b/tests/baselines/reference/narrowingOfDottedNames.js @@ -0,0 +1,80 @@ +//// [narrowingOfDottedNames.ts] +// Repro from #8383 + +class A { + prop: { a: string; }; +} + +class B { + prop: { b: string; } +} + +function isA(x: any): x is A { + return x instanceof A; +} + +function isB(x: any): x is B { + return x instanceof B; +} + +function f1(x: A | B) { + while (true) { + if (x instanceof A) { + x.prop.a; + } + else if (x instanceof B) { + x.prop.b; + } + } +} + +function f2(x: A | B) { + while (true) { + if (isA(x)) { + x.prop.a; + } + else if (isB(x)) { + x.prop.b; + } + } +} + + +//// [narrowingOfDottedNames.js] +// Repro from #8383 +var A = (function () { + function A() { + } + return A; +}()); +var B = (function () { + function B() { + } + return B; +}()); +function isA(x) { + return x instanceof A; +} +function isB(x) { + return x instanceof B; +} +function f1(x) { + while (true) { + if (x instanceof A) { + x.prop.a; + } + else if (x instanceof B) { + x.prop.b; + } + } +} +function f2(x) { + while (true) { + if (isA(x)) { + x.prop.a; + } + else if (isB(x)) { + x.prop.b; + } + } +} diff --git a/tests/baselines/reference/narrowingOfDottedNames.symbols b/tests/baselines/reference/narrowingOfDottedNames.symbols new file mode 100644 index 0000000000000..98f75372a4efd --- /dev/null +++ b/tests/baselines/reference/narrowingOfDottedNames.symbols @@ -0,0 +1,105 @@ +=== tests/cases/compiler/narrowingOfDottedNames.ts === +// Repro from #8383 + +class A { +>A : Symbol(A, Decl(narrowingOfDottedNames.ts, 0, 0)) + + prop: { a: string; }; +>prop : Symbol(A.prop, Decl(narrowingOfDottedNames.ts, 2, 9)) +>a : Symbol(a, Decl(narrowingOfDottedNames.ts, 3, 11)) +} + +class B { +>B : Symbol(B, Decl(narrowingOfDottedNames.ts, 4, 1)) + + prop: { b: string; } +>prop : Symbol(B.prop, Decl(narrowingOfDottedNames.ts, 6, 9)) +>b : Symbol(b, Decl(narrowingOfDottedNames.ts, 7, 11)) +} + +function isA(x: any): x is A { +>isA : Symbol(isA, Decl(narrowingOfDottedNames.ts, 8, 1)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 10, 13)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 10, 13)) +>A : Symbol(A, Decl(narrowingOfDottedNames.ts, 0, 0)) + + return x instanceof A; +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 10, 13)) +>A : Symbol(A, Decl(narrowingOfDottedNames.ts, 0, 0)) +} + +function isB(x: any): x is B { +>isB : Symbol(isB, Decl(narrowingOfDottedNames.ts, 12, 1)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 14, 13)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 14, 13)) +>B : Symbol(B, Decl(narrowingOfDottedNames.ts, 4, 1)) + + return x instanceof B; +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 14, 13)) +>B : Symbol(B, Decl(narrowingOfDottedNames.ts, 4, 1)) +} + +function f1(x: A | B) { +>f1 : Symbol(f1, Decl(narrowingOfDottedNames.ts, 16, 1)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 18, 12)) +>A : Symbol(A, Decl(narrowingOfDottedNames.ts, 0, 0)) +>B : Symbol(B, Decl(narrowingOfDottedNames.ts, 4, 1)) + + while (true) { + if (x instanceof A) { +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 18, 12)) +>A : Symbol(A, Decl(narrowingOfDottedNames.ts, 0, 0)) + + x.prop.a; +>x.prop.a : Symbol(a, Decl(narrowingOfDottedNames.ts, 3, 11)) +>x.prop : Symbol(A.prop, Decl(narrowingOfDottedNames.ts, 2, 9)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 18, 12)) +>prop : Symbol(A.prop, Decl(narrowingOfDottedNames.ts, 2, 9)) +>a : Symbol(a, Decl(narrowingOfDottedNames.ts, 3, 11)) + } + else if (x instanceof B) { +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 18, 12)) +>B : Symbol(B, Decl(narrowingOfDottedNames.ts, 4, 1)) + + x.prop.b; +>x.prop.b : Symbol(b, Decl(narrowingOfDottedNames.ts, 7, 11)) +>x.prop : Symbol(B.prop, Decl(narrowingOfDottedNames.ts, 6, 9)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 18, 12)) +>prop : Symbol(B.prop, Decl(narrowingOfDottedNames.ts, 6, 9)) +>b : Symbol(b, Decl(narrowingOfDottedNames.ts, 7, 11)) + } + } +} + +function f2(x: A | B) { +>f2 : Symbol(f2, Decl(narrowingOfDottedNames.ts, 27, 1)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 29, 12)) +>A : Symbol(A, Decl(narrowingOfDottedNames.ts, 0, 0)) +>B : Symbol(B, Decl(narrowingOfDottedNames.ts, 4, 1)) + + while (true) { + if (isA(x)) { +>isA : Symbol(isA, Decl(narrowingOfDottedNames.ts, 8, 1)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 29, 12)) + + x.prop.a; +>x.prop.a : Symbol(a, Decl(narrowingOfDottedNames.ts, 3, 11)) +>x.prop : Symbol(A.prop, Decl(narrowingOfDottedNames.ts, 2, 9)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 29, 12)) +>prop : Symbol(A.prop, Decl(narrowingOfDottedNames.ts, 2, 9)) +>a : Symbol(a, Decl(narrowingOfDottedNames.ts, 3, 11)) + } + else if (isB(x)) { +>isB : Symbol(isB, Decl(narrowingOfDottedNames.ts, 12, 1)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 29, 12)) + + x.prop.b; +>x.prop.b : Symbol(b, Decl(narrowingOfDottedNames.ts, 7, 11)) +>x.prop : Symbol(B.prop, Decl(narrowingOfDottedNames.ts, 6, 9)) +>x : Symbol(x, Decl(narrowingOfDottedNames.ts, 29, 12)) +>prop : Symbol(B.prop, Decl(narrowingOfDottedNames.ts, 6, 9)) +>b : Symbol(b, Decl(narrowingOfDottedNames.ts, 7, 11)) + } + } +} + diff --git a/tests/baselines/reference/narrowingOfDottedNames.types b/tests/baselines/reference/narrowingOfDottedNames.types new file mode 100644 index 0000000000000..697e080b661b3 --- /dev/null +++ b/tests/baselines/reference/narrowingOfDottedNames.types @@ -0,0 +1,115 @@ +=== tests/cases/compiler/narrowingOfDottedNames.ts === +// Repro from #8383 + +class A { +>A : A + + prop: { a: string; }; +>prop : { a: string; } +>a : string +} + +class B { +>B : B + + prop: { b: string; } +>prop : { b: string; } +>b : string +} + +function isA(x: any): x is A { +>isA : (x: any) => x is A +>x : any +>x : any +>A : A + + return x instanceof A; +>x instanceof A : boolean +>x : any +>A : typeof A +} + +function isB(x: any): x is B { +>isB : (x: any) => x is B +>x : any +>x : any +>B : B + + return x instanceof B; +>x instanceof B : boolean +>x : any +>B : typeof B +} + +function f1(x: A | B) { +>f1 : (x: A | B) => void +>x : A | B +>A : A +>B : B + + while (true) { +>true : boolean + + if (x instanceof A) { +>x instanceof A : boolean +>x : A | B +>A : typeof A + + x.prop.a; +>x.prop.a : string +>x.prop : { a: string; } +>x : A +>prop : { a: string; } +>a : string + } + else if (x instanceof B) { +>x instanceof B : boolean +>x : B +>B : typeof B + + x.prop.b; +>x.prop.b : string +>x.prop : { b: string; } +>x : B +>prop : { b: string; } +>b : string + } + } +} + +function f2(x: A | B) { +>f2 : (x: A | B) => void +>x : A | B +>A : A +>B : B + + while (true) { +>true : boolean + + if (isA(x)) { +>isA(x) : boolean +>isA : (x: any) => x is A +>x : A | B + + x.prop.a; +>x.prop.a : string +>x.prop : { a: string; } +>x : A +>prop : { a: string; } +>a : string + } + else if (isB(x)) { +>isB(x) : boolean +>isB : (x: any) => x is B +>x : B + + x.prop.b; +>x.prop.b : string +>x.prop : { b: string; } +>x : B +>prop : { b: string; } +>b : string + } + } +} + diff --git a/tests/cases/compiler/narrowingOfDottedNames.ts b/tests/cases/compiler/narrowingOfDottedNames.ts new file mode 100644 index 0000000000000..af417f0830c7b --- /dev/null +++ b/tests/cases/compiler/narrowingOfDottedNames.ts @@ -0,0 +1,39 @@ +// Repro from #8383 + +class A { + prop: { a: string; }; +} + +class B { + prop: { b: string; } +} + +function isA(x: any): x is A { + return x instanceof A; +} + +function isB(x: any): x is B { + return x instanceof B; +} + +function f1(x: A | B) { + while (true) { + if (x instanceof A) { + x.prop.a; + } + else if (x instanceof B) { + x.prop.b; + } + } +} + +function f2(x: A | B) { + while (true) { + if (isA(x)) { + x.prop.a; + } + else if (isB(x)) { + x.prop.b; + } + } +}