Stop looking at binding patterns for type argument inference entirely

andrewbranch · andrewbranch · commit c8f63928e181 · 2021-09-03T15:52:47.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -25274,7 +25274,7 @@ namespace ts {
                 if (result) {
                     return result;
                 }
-                if (!(contextFlags! & ContextFlags.SkipBindingPatterns) && isBindingPattern(declaration.name) && declaration.name.elements.length > 0) {
+                if (!(contextFlags! & ContextFlags.SkipBindingPatterns) && isBindingPattern(declaration.name)) {
                     // This is less a contextual type and more an implied shape - in some cases, this may be undesirable
                     return getTypeFromBindingPattern(declaration.name, /*includePatternInType*/ true, /*reportErrors*/ false);
                 }
@@ -28574,7 +28574,7 @@ namespace ts {
             // 'let f: (x: string) => number = wrap(s => s.length)', we infer from the declared type of 'f' to the
             // return type of 'wrap'.
             if (node.kind !== SyntaxKind.Decorator) {
-                const contextualType = getContextualType(node, every(signature.typeParameters, p => !!getDefaultFromTypeParameter(p)) ? ContextFlags.SkipBindingPatterns : ContextFlags.None);
+                const contextualType = getContextualType(node, ContextFlags.SkipBindingPatterns);
                 if (contextualType) {
                     // We clone the inference context to avoid disturbing a resolution in progress for an
                     // outer call expression. Effectively we just want a snapshot of whatever has been
diff --git a/tests/baselines/reference/declarationEmitDestructuring4.errors.txt b/tests/baselines/reference/declarationEmitDestructuring4.errors.txt
@@ -0,0 +1,17 @@
+tests/cases/compiler/declarationEmitDestructuring4.ts(9,22): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+
+
+==== tests/cases/compiler/declarationEmitDestructuring4.ts (1 errors) ====
+    // For an array binding pattern with empty elements,
+    // we will not make any modification and will emit
+    // the similar binding pattern users' have written
+    function baz([]) { }
+    function baz1([] = [1,2,3]) { }
+    function baz2([[]] = [[1,2,3]]) { }
+    
+    function baz3({}) { }
+    function baz4({} = { x: 10 }) { }
+                         ~
+!!! error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+    
+    
diff --git a/tests/baselines/reference/declarationEmitDestructuringObjectLiteralPattern.errors.txt b/tests/baselines/reference/declarationEmitDestructuringObjectLiteralPattern.errors.txt
@@ -1,11 +1,17 @@
+tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts(1,13): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts(1,19): error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts(2,23): error TS2353: Object literal may only specify known properties, and 'y4' does not exist in type '{ x4: any; }'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts(3,16): error TS2353: Object literal may only specify known properties, and 'x5' does not exist in type '{ y5: any; }'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts(5,27): error TS2353: Object literal may only specify known properties, and 'y7' does not exist in type '{ x7: any; }'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts(6,20): error TS2353: Object literal may only specify known properties, and 'x8' does not exist in type '{ y8: any; }'.
 
 
-==== tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts (4 errors) ====
+==== tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern.ts (6 errors) ====
     var { } = { x: 5, y: "hello" };
+                ~
+!!! error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+                      ~
+!!! error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
     var { x4 } = { x4: 5, y4: "hello" };
                           ~~
 !!! error TS2353: Object literal may only specify known properties, and 'y4' does not exist in type '{ x4: any; }'.
diff --git a/tests/baselines/reference/declarationEmitDestructuringObjectLiteralPattern1.errors.txt b/tests/baselines/reference/declarationEmitDestructuringObjectLiteralPattern1.errors.txt
@@ -1,11 +1,17 @@
+tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts(1,13): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts(1,19): error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts(2,23): error TS2353: Object literal may only specify known properties, and 'y4' does not exist in type '{ x4: any; }'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts(3,16): error TS2353: Object literal may only specify known properties, and 'x5' does not exist in type '{ y5: any; }'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts(5,27): error TS2353: Object literal may only specify known properties, and 'y7' does not exist in type '{ x7: any; }'.
 tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts(6,20): error TS2353: Object literal may only specify known properties, and 'x8' does not exist in type '{ y8: any; }'.
 
 
-==== tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts (4 errors) ====
+==== tests/cases/compiler/declarationEmitDestructuringObjectLiteralPattern1.ts (6 errors) ====
     var { } = { x: 5, y: "hello" };
+                ~
+!!! error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+                      ~
+!!! error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
     var { x4 } = { x4: 5, y4: "hello" };
                           ~~
 !!! error TS2353: Object literal may only specify known properties, and 'y4' does not exist in type '{ x4: any; }'.
diff --git a/tests/baselines/reference/declarationsAndAssignments.errors.txt b/tests/baselines/reference/declarationsAndAssignments.errors.txt
@@ -1,4 +1,6 @@
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(5,16): error TS2493: Tuple type '[number, string]' of length '2' has no element at index '2'.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(22,17): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(22,23): error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(23,25): error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{ x: any; }'.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(24,19): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{ y: any; }'.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(28,28): error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{ x: any; }'.
@@ -20,7 +22,7 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,6):
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,9): error TS2322: Type 'number' is not assignable to type 'string'.
 
 
-==== tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts (20 errors) ====
+==== tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts (22 errors) ====
     function f0() {
         var [] = [1, "hello"];
         var [x] = [1, "hello"];
@@ -45,6 +47,10 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,9):
     
     function f2() {
         var { } = { x: 5, y: "hello" };       // Error, no x and y in target
+                    ~
+!!! error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+                          ~
+!!! error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
         var { x } = { x: 5, y: "hello" };     // Error, no y in target
                             ~
 !!! error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{ x: any; }'.
diff --git a/tests/baselines/reference/destructuringTuple.errors.txt b/tests/baselines/reference/destructuringTuple.errors.txt
@@ -1,18 +1,11 @@
-tests/cases/compiler/destructuringTuple.ts(11,7): error TS2461: Type 'number' is not an array type.
-tests/cases/compiler/destructuringTuple.ts(11,48): error TS2769: No overload matches this call.
-  Overload 1 of 3, '(callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number', gave the following error.
-    Type 'never[]' is not assignable to type 'number'.
-  Overload 2 of 3, '(callbackfn: (previousValue: [], currentValue: number, currentIndex: number, array: number[]) => [], initialValue: []): []', gave the following error.
-    Type 'never[]' is not assignable to type '[]'.
-      Target allows only 0 element(s) but source may have more.
 tests/cases/compiler/destructuringTuple.ts(11,60): error TS2769: No overload matches this call.
   Overload 1 of 2, '(...items: ConcatArray<never>[]): never[]', gave the following error.
     Argument of type 'number' is not assignable to parameter of type 'ConcatArray<never>'.
   Overload 2 of 2, '(...items: ConcatArray<never>[]): never[]', gave the following error.
     Argument of type 'number' is not assignable to parameter of type 'ConcatArray<never>'.
 
 
-==== tests/cases/compiler/destructuringTuple.ts (3 errors) ====
+==== tests/cases/compiler/destructuringTuple.ts (1 errors) ====
     declare var tuple: [boolean, number, ...string[]];
     
     const [a, b, c, ...rest] = tuple;
@@ -24,17 +17,6 @@ tests/cases/compiler/destructuringTuple.ts(11,60): error TS2769: No overload mat
     // Repros from #32140
     
     const [oops1] = [1, 2, 3].reduce((accu, el) => accu.concat(el), []);
-          ~~~~~~~
-!!! error TS2461: Type 'number' is not an array type.
-                                                   ~~~~~~~~~~~~~~~
-!!! error TS2769: No overload matches this call.
-!!! error TS2769:   Overload 1 of 3, '(callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number', gave the following error.
-!!! error TS2769:     Type 'never[]' is not assignable to type 'number'.
-!!! error TS2769:   Overload 2 of 3, '(callbackfn: (previousValue: [], currentValue: number, currentIndex: number, array: number[]) => [], initialValue: []): []', gave the following error.
-!!! error TS2769:     Type 'never[]' is not assignable to type '[]'.
-!!! error TS2769:       Target allows only 0 element(s) but source may have more.
-!!! related TS6502 /.ts/lib.es5.d.ts:1412:24: The expected type comes from the return type of this signature.
-!!! related TS6502 /.ts/lib.es5.d.ts:1418:27: The expected type comes from the return type of this signature.
                                                                ~~
 !!! error TS2769: No overload matches this call.
 !!! error TS2769:   Overload 1 of 2, '(...items: ConcatArray<never>[]): never[]', gave the following error.
diff --git a/tests/baselines/reference/destructuringTuple.types b/tests/baselines/reference/destructuringTuple.types
@@ -23,20 +23,20 @@ declare var receiver: typeof tuple;
 // Repros from #32140
 
 const [oops1] = [1, 2, 3].reduce((accu, el) => accu.concat(el), []);
->oops1 : any
->[1, 2, 3].reduce((accu, el) => accu.concat(el), []) : number
+>oops1 : never
+>[1, 2, 3].reduce((accu, el) => accu.concat(el), []) : never[]
 >[1, 2, 3].reduce : { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }
 >[1, 2, 3] : number[]
 >1 : 1
 >2 : 2
 >3 : 3
 >reduce : { (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number): number; (callbackfn: (previousValue: number, currentValue: number, currentIndex: number, array: number[]) => number, initialValue: number): number; <U>(callbackfn: (previousValue: U, currentValue: number, currentIndex: number, array: number[]) => U, initialValue: U): U; }
->(accu, el) => accu.concat(el) : (accu: [], el: number) => never[]
->accu : []
+>(accu, el) => accu.concat(el) : (accu: never[], el: number) => never[]
+>accu : never[]
 >el : number
 >accu.concat(el) : never[]
 >accu.concat : { (...items: ConcatArray<never>[]): never[]; (...items: ConcatArray<never>[]): never[]; }
->accu : []
+>accu : never[]
 >concat : { (...items: ConcatArray<never>[]): never[]; (...items: ConcatArray<never>[]): never[]; }
 >el : number
 >[] : never[]
diff --git a/tests/baselines/reference/emptyObjectBindingPatternParameter04.errors.txt b/tests/baselines/reference/emptyObjectBindingPatternParameter04.errors.txt
@@ -0,0 +1,15 @@
+tests/cases/conformance/es6/destructuring/emptyObjectBindingPatternParameter04.ts(1,18): error TS2353: Object literal may only specify known properties, and 'a' does not exist in type '{}'.
+tests/cases/conformance/es6/destructuring/emptyObjectBindingPatternParameter04.ts(1,24): error TS2353: Object literal may only specify known properties, and 'b' does not exist in type '{}'.
+tests/cases/conformance/es6/destructuring/emptyObjectBindingPatternParameter04.ts(1,32): error TS2353: Object literal may only specify known properties, and 'c' does not exist in type '{}'.
+
+
+==== tests/cases/conformance/es6/destructuring/emptyObjectBindingPatternParameter04.ts (3 errors) ====
+    function f({} = {a: 1, b: "2", c: true}) {
+                     ~
+!!! error TS2353: Object literal may only specify known properties, and 'a' does not exist in type '{}'.
+                           ~
+!!! error TS2353: Object literal may only specify known properties, and 'b' does not exist in type '{}'.
+                                   ~
+!!! error TS2353: Object literal may only specify known properties, and 'c' does not exist in type '{}'.
+        var x, y, z;
+    }
diff --git a/tests/baselines/reference/missingAndExcessProperties.errors.txt b/tests/baselines/reference/missingAndExcessProperties.errors.txt
@@ -10,6 +10,8 @@ tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(12,8): e
 tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(12,11): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(13,18): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(14,8): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(20,17): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(20,23): error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
 tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(21,25): error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{ x: any; }'.
 tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(22,19): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{ y: any; }'.
 tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(29,14): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
@@ -18,7 +20,7 @@ tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(30,22):
 tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(31,16): error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{ y: number; }'.
 
 
-==== tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts (18 errors) ====
+==== tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts (20 errors) ====
     // Missing properties
     function f1() {
         var { x, y } = {};
@@ -67,6 +69,10 @@ tests/cases/conformance/es6/destructuring/missingAndExcessProperties.ts(31,16):
     // Excess properties
     function f3() {
         var { } = { x: 0, y: 0 };
+                    ~
+!!! error TS2353: Object literal may only specify known properties, and 'x' does not exist in type '{}'.
+                          ~
+!!! error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{}'.
         var { x } = { x: 0, y: 0 };
                             ~
 !!! error TS2353: Object literal may only specify known properties, and 'y' does not exist in type '{ x: any; }'.
