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Fix type predicates with structurally identical types #12251

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Merged
merged 4 commits into from
Nov 15, 2016
Merged

Fix type predicates with structurally identical types #12251

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6d28595
Add repro test
ahejlsberg Nov 15, 2016
2bcb6e9
Accept baselines
ahejlsberg Nov 15, 2016
d2c0952
Revert type predicates to not have instanceof special casing
ahejlsberg Nov 15, 2016
b6b4361
Accept new baselines
ahejlsberg Nov 15, 2016
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12 changes: 6 additions & 6 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -9721,20 +9721,20 @@ namespace ts {
}

if (targetType) {
return getNarrowedType(type, targetType, assumeTrue);
return getNarrowedType(type, targetType, assumeTrue, isTypeInstanceOf);
}

return type;
}

function getNarrowedType(type: Type, candidate: Type, assumeTrue: boolean) {
function getNarrowedType(type: Type, candidate: Type, assumeTrue: boolean, isRelated: (source: Type, target: Type) => boolean) {
if (!assumeTrue) {
return filterType(type, t => !isTypeInstanceOf(t, candidate));
return filterType(type, t => !isRelated(t, candidate));
}
// If the current type is a union type, remove all constituents that couldn't be instances of
// the candidate type. If one or more constituents remain, return a union of those.
if (type.flags & TypeFlags.Union) {
const assignableType = filterType(type, t => isTypeInstanceOf(t, candidate));
const assignableType = filterType(type, t => isRelated(t, candidate));
if (!(assignableType.flags & TypeFlags.Never)) {
return assignableType;
}
Expand Down Expand Up @@ -9770,7 +9770,7 @@ namespace ts {
const predicateArgument = callExpression.arguments[predicate.parameterIndex];
if (predicateArgument) {
if (isMatchingReference(reference, predicateArgument)) {
return getNarrowedType(type, predicate.type, assumeTrue);
return getNarrowedType(type, predicate.type, assumeTrue, isTypeSubtypeOf);
}
if (containsMatchingReference(reference, predicateArgument)) {
return declaredType;
Expand All @@ -9783,7 +9783,7 @@ namespace ts {
const accessExpression = invokedExpression as ElementAccessExpression | PropertyAccessExpression;
const possibleReference = skipParentheses(accessExpression.expression);
if (isMatchingReference(reference, possibleReference)) {
return getNarrowedType(type, predicate.type, assumeTrue);
return getNarrowedType(type, predicate.type, assumeTrue, isTypeSubtypeOf);
}
if (containsMatchingReference(reference, possibleReference)) {
return declaredType;
Expand Down
12 changes: 6 additions & 6 deletions tests/baselines/reference/controlFlowBinaryOrExpression.symbols
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Expand Up @@ -64,19 +64,19 @@ if (isNodeList(sourceObj)) {
>sourceObj : Symbol(sourceObj, Decl(controlFlowBinaryOrExpression.ts, 23, 3))

sourceObj.length;
>sourceObj.length : Symbol(NodeList.length, Decl(controlFlowBinaryOrExpression.ts, 10, 27))
>sourceObj.length : Symbol(length, Decl(controlFlowBinaryOrExpression.ts, 10, 27), Decl(controlFlowBinaryOrExpression.ts, 14, 33))
>sourceObj : Symbol(sourceObj, Decl(controlFlowBinaryOrExpression.ts, 23, 3))
>length : Symbol(NodeList.length, Decl(controlFlowBinaryOrExpression.ts, 10, 27))
>length : Symbol(length, Decl(controlFlowBinaryOrExpression.ts, 10, 27), Decl(controlFlowBinaryOrExpression.ts, 14, 33))
}

if (isHTMLCollection(sourceObj)) {
>isHTMLCollection : Symbol(isHTMLCollection, Decl(controlFlowBinaryOrExpression.ts, 18, 67))
>sourceObj : Symbol(sourceObj, Decl(controlFlowBinaryOrExpression.ts, 23, 3))

sourceObj.length;
>sourceObj.length : Symbol(HTMLCollection.length, Decl(controlFlowBinaryOrExpression.ts, 14, 33))
>sourceObj.length : Symbol(length, Decl(controlFlowBinaryOrExpression.ts, 10, 27), Decl(controlFlowBinaryOrExpression.ts, 14, 33))
>sourceObj : Symbol(sourceObj, Decl(controlFlowBinaryOrExpression.ts, 23, 3))
>length : Symbol(HTMLCollection.length, Decl(controlFlowBinaryOrExpression.ts, 14, 33))
>length : Symbol(length, Decl(controlFlowBinaryOrExpression.ts, 10, 27), Decl(controlFlowBinaryOrExpression.ts, 14, 33))
}

if (isNodeList(sourceObj) || isHTMLCollection(sourceObj)) {
Expand All @@ -86,8 +86,8 @@ if (isNodeList(sourceObj) || isHTMLCollection(sourceObj)) {
>sourceObj : Symbol(sourceObj, Decl(controlFlowBinaryOrExpression.ts, 23, 3))

sourceObj.length;
>sourceObj.length : Symbol(length, Decl(controlFlowBinaryOrExpression.ts, 10, 27), Decl(controlFlowBinaryOrExpression.ts, 14, 33))
>sourceObj.length : Symbol(NodeList.length, Decl(controlFlowBinaryOrExpression.ts, 10, 27))
>sourceObj : Symbol(sourceObj, Decl(controlFlowBinaryOrExpression.ts, 23, 3))
>length : Symbol(length, Decl(controlFlowBinaryOrExpression.ts, 10, 27), Decl(controlFlowBinaryOrExpression.ts, 14, 33))
>length : Symbol(NodeList.length, Decl(controlFlowBinaryOrExpression.ts, 10, 27))
}

8 changes: 4 additions & 4 deletions tests/baselines/reference/controlFlowBinaryOrExpression.types
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Expand Up @@ -80,7 +80,7 @@ if (isNodeList(sourceObj)) {

sourceObj.length;
>sourceObj.length : number
>sourceObj : NodeList
>sourceObj : NodeList | HTMLCollection
>length : number
}

Expand All @@ -91,7 +91,7 @@ if (isHTMLCollection(sourceObj)) {

sourceObj.length;
>sourceObj.length : number
>sourceObj : HTMLCollection
>sourceObj : NodeList | HTMLCollection
>length : number
}

Expand All @@ -102,11 +102,11 @@ if (isNodeList(sourceObj) || isHTMLCollection(sourceObj)) {
>sourceObj : NodeList | HTMLCollection | { a: string; }
>isHTMLCollection(sourceObj) : boolean
>isHTMLCollection : (sourceObj: any) => sourceObj is HTMLCollection
>sourceObj : HTMLCollection | { a: string; }
>sourceObj : { a: string; }

sourceObj.length;
>sourceObj.length : number
>sourceObj : NodeList | HTMLCollection
>sourceObj : NodeList
>length : number
}

76 changes: 76 additions & 0 deletions tests/baselines/reference/instanceofWithStructurallyIdenticalTypes.errors.txt
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@@ -0,0 +1,76 @@
tests/cases/compiler/instanceofWithStructurallyIdenticalTypes.ts(32,18): error TS2339: Property 'item' does not exist on type 'never'.


==== tests/cases/compiler/instanceofWithStructurallyIdenticalTypes.ts (1 errors) ====
// Repro from #7271

class C1 { item: string }
class C2 { item: string[] }
class C3 { item: string }

function foo1(x: C1 | C2 | C3): string {
if (x instanceof C1) {
return x.item;
}
else if (x instanceof C2) {
return x.item[0];
}
else if (x instanceof C3) {
return x.item;
}
return "error";
}

function isC1(c: C1 | C2 | C3): c is C1 { return c instanceof C1 }
function isC2(c: C1 | C2 | C3): c is C2 { return c instanceof C2 }
function isC3(c: C1 | C2 | C3): c is C3 { return c instanceof C3 }

function foo2(x: C1 | C2 | C3): string {
if (isC1(x)) {
return x.item;
}
else if (isC2(x)) {
return x.item[0];
}
else if (isC3(x)) {
return x.item;
~~~~
!!! error TS2339: Property 'item' does not exist on type 'never'.
}
return "error";
}

// More tests

class A { a: string }
class A1 extends A { }
class A2 { a: string }
class B extends A { b: string }

function goo(x: A) {
if (x instanceof A) {
x; // A
}
else {
x; // never
}
if (x instanceof A1) {
x; // A1
}
else {
x; // A
}
if (x instanceof A2) {
x; // A2
}
else {
x; // A
}
if (x instanceof B) {
x; // B
}
else {
x; // A
}
}

46 changes: 46 additions & 0 deletions tests/baselines/reference/typePredicateStructuralMatch.js
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@@ -0,0 +1,46 @@
//// [typePredicateStructuralMatch.ts]
// Repro from #12235

getResults1([]);
getResults1({data: []});

getResults2([]);
getResults2({data: []});

type Result = { value: string };
type Results = Result[];

function isResponseInData<T>(value: T | { data: T}): value is { data: T } {
return value.hasOwnProperty('data');
}

function getResults1(value: Results | { data: Results }): Results {
return isResponseInData(value) ? value.data : value;
}

function isPlainResponse<T>(value: T | { data: T}): value is T {
return !value.hasOwnProperty('data');
}

function getResults2(value: Results | { data: Results }): Results {
return isPlainResponse(value) ? value : value.data;
}

//// [typePredicateStructuralMatch.js]
// Repro from #12235
getResults1([]);
getResults1({ data: [] });
getResults2([]);
getResults2({ data: [] });
function isResponseInData(value) {
return value.hasOwnProperty('data');
}
function getResults1(value) {
return isResponseInData(value) ? value.data : value;
}
function isPlainResponse(value) {
return !value.hasOwnProperty('data');
}
function getResults2(value) {
return isPlainResponse(value) ? value : value.data;
}
91 changes: 91 additions & 0 deletions tests/baselines/reference/typePredicateStructuralMatch.symbols
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@@ -0,0 +1,91 @@
=== tests/cases/compiler/typePredicateStructuralMatch.ts ===
// Repro from #12235

getResults1([]);
>getResults1 : Symbol(getResults1, Decl(typePredicateStructuralMatch.ts, 13, 1))

getResults1({data: []});
>getResults1 : Symbol(getResults1, Decl(typePredicateStructuralMatch.ts, 13, 1))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 3, 13))

getResults2([]);
>getResults2 : Symbol(getResults2, Decl(typePredicateStructuralMatch.ts, 21, 1))

getResults2({data: []});
>getResults2 : Symbol(getResults2, Decl(typePredicateStructuralMatch.ts, 21, 1))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 6, 13))

type Result = { value: string };
>Result : Symbol(Result, Decl(typePredicateStructuralMatch.ts, 6, 24))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 8, 15))

type Results = Result[];
>Results : Symbol(Results, Decl(typePredicateStructuralMatch.ts, 8, 32))
>Result : Symbol(Result, Decl(typePredicateStructuralMatch.ts, 6, 24))

function isResponseInData<T>(value: T | { data: T}): value is { data: T } {
>isResponseInData : Symbol(isResponseInData, Decl(typePredicateStructuralMatch.ts, 9, 24))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 11, 26))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 11, 29))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 11, 26))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 11, 41))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 11, 26))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 11, 29))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 11, 63))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 11, 26))

return value.hasOwnProperty('data');
>value.hasOwnProperty : Symbol(Object.hasOwnProperty, Decl(lib.d.ts, --, --))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 11, 29))
>hasOwnProperty : Symbol(Object.hasOwnProperty, Decl(lib.d.ts, --, --))
}

function getResults1(value: Results | { data: Results }): Results {
>getResults1 : Symbol(getResults1, Decl(typePredicateStructuralMatch.ts, 13, 1))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 15, 21))
>Results : Symbol(Results, Decl(typePredicateStructuralMatch.ts, 8, 32))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 15, 39))
>Results : Symbol(Results, Decl(typePredicateStructuralMatch.ts, 8, 32))
>Results : Symbol(Results, Decl(typePredicateStructuralMatch.ts, 8, 32))

return isResponseInData(value) ? value.data : value;
>isResponseInData : Symbol(isResponseInData, Decl(typePredicateStructuralMatch.ts, 9, 24))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 15, 21))
>value.data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 15, 39))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 15, 21))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 15, 39))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 15, 21))
}

function isPlainResponse<T>(value: T | { data: T}): value is T {
>isPlainResponse : Symbol(isPlainResponse, Decl(typePredicateStructuralMatch.ts, 17, 1))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 19, 25))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 19, 28))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 19, 25))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 19, 40))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 19, 25))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 19, 28))
>T : Symbol(T, Decl(typePredicateStructuralMatch.ts, 19, 25))

return !value.hasOwnProperty('data');
>value.hasOwnProperty : Symbol(Object.hasOwnProperty, Decl(lib.d.ts, --, --))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 19, 28))
>hasOwnProperty : Symbol(Object.hasOwnProperty, Decl(lib.d.ts, --, --))
}

function getResults2(value: Results | { data: Results }): Results {
>getResults2 : Symbol(getResults2, Decl(typePredicateStructuralMatch.ts, 21, 1))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 23, 21))
>Results : Symbol(Results, Decl(typePredicateStructuralMatch.ts, 8, 32))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 23, 39))
>Results : Symbol(Results, Decl(typePredicateStructuralMatch.ts, 8, 32))
>Results : Symbol(Results, Decl(typePredicateStructuralMatch.ts, 8, 32))

return isPlainResponse(value) ? value : value.data;
>isPlainResponse : Symbol(isPlainResponse, Decl(typePredicateStructuralMatch.ts, 17, 1))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 23, 21))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 23, 21))
>value.data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 23, 39))
>value : Symbol(value, Decl(typePredicateStructuralMatch.ts, 23, 21))
>data : Symbol(data, Decl(typePredicateStructuralMatch.ts, 23, 39))
}
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