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Do not use contextual signatures with too few parameters

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This commit is contained in:
Nathan Shively-Sanders 2016-10-27 22:52:01 -07:00
parent 4e57f700d0
commit 2c09574f18
4 changed files with 35 additions and 27 deletions
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40
src/compiler/checker.ts
View File

@ -10337,6 +10337,10 @@ namespace ts {
if (!type) {
return undefined;
}
// If the contextual signature has fewer parameters than the function expression, do not use it
if (isFunctionExpressionOrArrowFunction(node) && isAritySmaller(type, node)) {
return undefined;
}
if (!(type.flags & TypeFlags.Union)) {
return getNonGenericSignature(type);
}
@ -10371,6 +10375,26 @@ namespace ts {
return result;
}
function isAritySmaller(sourceType: Type, target: FunctionExpression | ArrowFunction) {
if (isFunctionType(sourceType)) {
let targetParameterCount = 0;
for (; targetParameterCount < target.parameters.length; targetParameterCount++) {
const param = target.parameters[targetParameterCount];
if (param.initializer || param.questionToken || param.dotDotDotToken || isJSDocOptionalParameter(param)) {
break;
}
}
if (target.parameters.length && parameterIsThisKeyword(target.parameters[0])) {
targetParameterCount--;
}
const sourceSignatures = getSignaturesOfType(sourceType, SignatureKind.Call);
const sourceLengths = sourceSignatures.map(sig => !sig.hasRestParameter ? sig.parameters.length : Number.MAX_VALUE);
return forEach(sourceLengths, len => len < targetParameterCount);
}
return false;
}
/**
* Detect if the mapper implies an inference context. Specifically, there are 4 possible values
* for a mapper. Let's go through each one of them:
@ -11884,12 +11908,6 @@ namespace ts {
// If the effective argument type is 'undefined', there is no synthetic type
// for the argument. In that case, we should check the argument.
if (argType === undefined) {
// If the parameter and argument are both functions and the parameter has fewer arguments than the argument,
// then this signature is not applicable. Exit early to avoid fixing incorrect
// contextual types to the function expression parameters.
if (!reportErrors && isAritySmaller(paramType, arg)) {
return false;
}
argType = checkExpressionWithContextualType(arg, paramType, excludeArgument && excludeArgument[i] ? identityMapper : undefined);
}
@ -11904,16 +11922,6 @@ namespace ts {
return true;
}
function isAritySmaller(sourceType: Type, target: Expression) {
if (isFunctionExpressionOrArrowFunction(target) && isFunctionType(sourceType)) {
const sourceSignatures = getSignaturesOfType(sourceType, SignatureKind.Call);
const sourceLengths = sourceSignatures.map(sig => !sig.hasRestParameter ? sig.parameters.length : Number.MAX_VALUE);
return forEach(sourceLengths, len => len < target.parameters.length);
}
return false;
}
/**
* Returns the this argument in calls like x.f(...) and x[f](...). Undefined otherwise.
*/

6
tests/baselines/reference/contextualTypingOfTooShortOverloads.types
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@ -7,9 +7,9 @@ var use: Overload;
use((req, res) => {});
>use((req, res) => {}) : void
>use : Overload
>(req, res) => {} : (req: number, res: number) => void
>req : number
>res : number
>(req, res) => {} : (req: any, res: any) => void
>req : any
>res : any
interface Overload {
>Overload : Overload

4
tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments.types
View File

@ -122,8 +122,8 @@ module GenericParameter {
>'' : ""
var r11 = foo6(<T>(x: T, y?: T) => ''); // any => string (+1 overload)
>r11 : any
>foo6(<T>(x: T, y?: T) => '') : any
>r11 : { (x: any): string; (x: any, y?: any): string; }
>foo6(<T>(x: T, y?: T) => '') : { (x: any): string; (x: any, y?: any): string; }
>foo6 : <T>(cb: { (x: T): string; (x: T, y?: T): string; }) => { (x: T): string; (x: T, y?: T): string; }
><T>(x: T, y?: T) => '' : <T>(x: T, y?: T) => string
>T : T

12
tests/baselines/reference/partiallyAnnotatedFunctionInferenceError.errors.txt
View File

@ -1,6 +1,6 @@
tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partiallyAnnotatedFunctionInferenceError.ts(12,11): error TS2345: Argument of type '(t1: D, t2: C, t3: any) => void' is not assignable to parameter of type '(t: C, t1: C) => void'.
tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partiallyAnnotatedFunctionInferenceError.ts(13,11): error TS2345: Argument of type '(t1: C, t2: D, t3: any) => void' is not assignable to parameter of type '(t: C, t1: C) => void'.
tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partiallyAnnotatedFunctionInferenceError.ts(14,11): error TS2345: Argument of type '(t1: C, t2: C, t3: D) => void' is not assignable to parameter of type '(t: C, t1: C) => void'.
tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partiallyAnnotatedFunctionInferenceError.ts(12,11): error TS2345: Argument of type '(t1: D, t2: any, t3: any) => void' is not assignable to parameter of type '(t: any, t1: any) => void'.
tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partiallyAnnotatedFunctionInferenceError.ts(13,11): error TS2345: Argument of type '(t1: any, t2: D, t3: any) => void' is not assignable to parameter of type '(t: any, t1: any) => void'.
tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partiallyAnnotatedFunctionInferenceError.ts(14,11): error TS2345: Argument of type '(t1: any, t2: any, t3: D) => void' is not assignable to parameter of type '(t: any, t1: any) => void'.
==== tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partiallyAnnotatedFunctionInferenceError.ts (3 errors) ====
@ -17,11 +17,11 @@ tests/cases/conformance/types/contextualTypes/partiallyAnnotatedFunction/partial
// more args
testError((t1: D, t2, t3) => {})
~~~~~~~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(t1: D, t2: C, t3: any) => void' is not assignable to parameter of type '(t: C, t1: C) => void'.
!!! error TS2345: Argument of type '(t1: D, t2: any, t3: any) => void' is not assignable to parameter of type '(t: any, t1: any) => void'.
testError((t1, t2: D, t3) => {})
~~~~~~~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(t1: C, t2: D, t3: any) => void' is not assignable to parameter of type '(t: C, t1: C) => void'.
!!! error TS2345: Argument of type '(t1: any, t2: D, t3: any) => void' is not assignable to parameter of type '(t: any, t1: any) => void'.
testError((t1, t2, t3: D) => {})
~~~~~~~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(t1: C, t2: C, t3: D) => void' is not assignable to parameter of type '(t: C, t1: C) => void'.
!!! error TS2345: Argument of type '(t1: any, t2: any, t3: D) => void' is not assignable to parameter of type '(t: any, t1: any) => void'.