Remove binding pattern normalization

src/compiler/checker.ts

@@ -4306,10 +4306,9 @@ namespace ts {
             if (strictNullChecks && declaration.initializer && !(getFalsyFlags(checkExpressionCached(declaration.initializer)) & TypeFlags.Undefined)) {
                 type = getTypeWithFacts(type, TypeFacts.NEUndefined);
             }
-            type = declaration.initializer ?
+            return declaration.initializer ?
                 getUnionType([type, checkExpressionCached(declaration.initializer)], /*subtypeReduction*/ true) :
                 type;
-            return shouldKeepLiteralType(declaration) ? type : getWidenedLiteralType(type);
         }
 
         function getTypeForDeclarationFromJSDocComment(declaration: Node) {

tests/baselines/reference/arrowFunctionExpressions.types

@@ -103,7 +103,7 @@ var p9 = ({ a: { b = 1 } = { b: 1 } }) => { };
 >p9 : ({ a: { b } }: { a?: { b?: 1; }; }) => void
 >({ a: { b = 1 } = { b: 1 } }) => { } : ({ a: { b } }: { a?: { b?: 1; }; }) => void
 >a : any
->b : number
+>b : 1
 >1 : 1
 >{ b: 1 } : { b?: 1; }
 >b : number

tests/baselines/reference/contextuallyTypedBindingInitializerNegative.types

@@ -94,7 +94,7 @@ interface StringUnion {
 }
 function h({ prop = "baz" }: StringUnion) {}
 >h : ({ prop }: StringUnion) => void
->prop : string
+>prop : "foo" | "bar" | "baz"
 >"baz" : "baz"
 >StringUnion : StringUnion
 

tests/baselines/reference/contextuallyTypedIife.types

@@ -209,15 +209,15 @@
 >19 : 19
 
 (({ u = 22 } = { u: 23 }) => u)();
->(({ u = 22 } = { u: 23 }) => u)() : number
->(({ u = 22 } = { u: 23 }) => u) : ({ u }?: { u?: 23; }) => number
->({ u = 22 } = { u: 23 }) => u : ({ u }?: { u?: 23; }) => number
->u : number
+>(({ u = 22 } = { u: 23 }) => u)() : 22 | 23
+>(({ u = 22 } = { u: 23 }) => u) : ({ u }?: { u?: 23; }) => 22 | 23
+>({ u = 22 } = { u: 23 }) => u : ({ u }?: { u?: 23; }) => 22 | 23
+>u : 22 | 23
 >22 : 22
 >{ u: 23 } : { u?: 23; }
 >u : number
 >23 : 23
->u : number
+>u : 22 | 23
 
 // contextually typed parameters.
 let twelve = (f => f(12))(i => i);

tests/baselines/reference/contextuallyTypedIifeStrict.types

@@ -209,15 +209,15 @@
 >19 : 19
 
 (({ u = 22 } = { u: 23 }) => u)();
->(({ u = 22 } = { u: 23 }) => u)() : number
->(({ u = 22 } = { u: 23 }) => u) : ({ u }?: { u?: 23; }) => number
->({ u = 22 } = { u: 23 }) => u : ({ u }?: { u?: 23; }) => number
->u : number
+>(({ u = 22 } = { u: 23 }) => u)() : 22 | 23
+>(({ u = 22 } = { u: 23 }) => u) : ({ u }?: { u?: 23; }) => 22 | 23
+>({ u = 22 } = { u: 23 }) => u : ({ u }?: { u?: 23; }) => 22 | 23
+>u : 22 | 23
 >22 : 22
 >{ u: 23 } : { u?: 23; }
 >u : number
 >23 : 23
->u : number
+>u : 22 | 23
 
 // contextually typed parameters.
 let twelve = (f => f(12))(i => i);

tests/baselines/reference/declarationEmitDestructuring2.types

@@ -1,7 +1,7 @@
 === tests/cases/compiler/declarationEmitDestructuring2.ts ===
 function f({x = 10, y: [a, b, c, d] = [1, 2, 3, 4]} = { x: 10, y: [2, 4, 6, 8] }) { }
 >f : ({ x, y: [a, b, c, d] }?: { x?: 10; y?: [2, 4, 6, 8]; }) => void
->x : number
+>x : 10
 >10 : 10
 >y : any
 >a : number

tests/baselines/reference/declarationEmitDestructuringArrayPattern2.types

@@ -11,9 +11,9 @@ var [x10, [y10, [z10]]] = [1, ["hello", [true]]];
 >true : true
 
 var [x11 = 0, y11 = ""] = [1, "hello"];
->x11 : number
+>x11 : 1 | 0
 >0 : 0
->y11 : string
+>y11 : "hello" | ""
 >"" : ""
 >[1, "hello"] : [1, "hello"]
 >1 : 1

tests/baselines/reference/declarationsAndAssignments.errors.txt

@@ -5,7 +5,10 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(23,25):
 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; }'.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(29,22): 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(58,9): error TS2403: Subsequent variable declarations must have the same type.  Variable 'y' has type 'string | number' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 55:16, but here has type 'string'.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(51,9): error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type '1 | 0' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 49:9, but here has type 'number'.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(52,9): error TS2403: Subsequent variable declarations must have the same type.  Variable 'y' has type '"hello" | ""' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 49:16, but here has type 'string'.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(57,9): error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type '1 | 0' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 55:9, but here has type 'number'.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(58,9): error TS2403: Subsequent variable declarations must have the same type.  Variable 'y' has type 'string | 1' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 55:16, but here has type 'string'.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(62,10): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(62,13): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(62,16): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
@@ -25,7 +28,7 @@ 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 (22 errors) ====
+==== tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts (25 errors) ====
     function f0() {
         var [] = [1, "hello"];
         var [x] = [1, "hello"];
@@ -91,15 +94,21 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,9):
     function f6() {
         var [x = 0, y = ""] = [1, "hello"];
         var x: number;
+            ~
+!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type '1 | 0' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 49:9, but here has type 'number'.
         var y: string;
+            ~
+!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'y' has type '"hello" | ""' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 49:16, but here has type 'string'.
     }
 
     function f7() {
         var [x = 0, y = 1] = [1, "hello"];  // Error, initializer for y must be string
         var x: number;
+            ~
+!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type '1 | 0' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 55:9, but here has type 'number'.
         var y: string;
             ~
-!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'y' has type 'string | number' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 55:16, but here has type 'string'.
+!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'y' has type 'string | 1' at tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts 55:16, but here has type 'string'.
     }
 
     function f8() {

tests/baselines/reference/declarationsAndAssignments.types

@@ -217,38 +217,38 @@ function f6() {
 >f6 : () => void
 
     var [x = 0, y = ""] = [1, "hello"];
->x : number
+>x : 1 | 0
 >0 : 0
->y : string
+>y : "hello" | ""
 >"" : ""
 >[1, "hello"] : [1, "hello"]
 >1 : 1
 >"hello" : "hello"
 
     var x: number;
->x : number
+>x : 1 | 0
 
     var y: string;
->y : string
+>y : "hello" | ""
 }
 
 function f7() {
 >f7 : () => void
 
     var [x = 0, y = 1] = [1, "hello"];  // Error, initializer for y must be string
->x : number
+>x : 1 | 0
 >0 : 0
->y : string | number
+>y : string | 1
 >1 : 1
 >[1, "hello"] : [1, string]
 >1 : 1
 >"hello" : "hello"
 
     var x: number;
->x : number
+>x : 1 | 0
 
     var y: string;
->y : string | number
+>y : string | 1
 }
 
 function f8() {

tests/baselines/reference/destructuringArrayBindingPatternAndAssignment2.types

@@ -43,7 +43,7 @@ function bar(): J {
 >3 : 3
 }
 var [b3 = "string", b4, b5] = bar();  // Error
->b3 : string | Number
+>b3 : Number | "string"
 >"string" : "string"
 >b4 : Number
 >b5 : Number

tests/baselines/reference/destructuringVariableDeclaration1ES5.types

@@ -46,7 +46,7 @@ var temp = { t1: true, t2: "false" };
 >"false" : "false"
 
 var [b2 = 3, b3 = true, b4 = temp] = [3, false, { t1: false, t2: "hello" }];
->b2 : number
+>b2 : 3
 >3 : 3
 >b3 : boolean
 >true : true
@@ -62,9 +62,9 @@ var [b2 = 3, b3 = true, b4 = temp] = [3, false, { t1: false, t2: "hello" }];
 >"hello" : "hello"
 
 var [b5 = 3, b6 = true, b7 = temp] = [undefined, undefined, undefined];
->b5 : number
+>b5 : 3
 >3 : 3
->b6 : boolean
+>b6 : true
 >true : true
 >b7 : { t1: boolean; t2: string; }
 >temp : { t1: boolean; t2: string; }

tests/baselines/reference/destructuringVariableDeclaration1ES5iterable.types

@@ -46,7 +46,7 @@ var temp = { t1: true, t2: "false" };
 >"false" : "false"
 
 var [b2 = 3, b3 = true, b4 = temp] = [3, false, { t1: false, t2: "hello" }];
->b2 : number
+>b2 : 3
 >3 : 3
 >b3 : boolean
 >true : true
@@ -62,9 +62,9 @@ var [b2 = 3, b3 = true, b4 = temp] = [3, false, { t1: false, t2: "hello" }];
 >"hello" : "hello"
 
 var [b5 = 3, b6 = true, b7 = temp] = [undefined, undefined, undefined];
->b5 : number
+>b5 : 3
 >3 : 3
->b6 : boolean
+>b6 : true
 >true : true
 >b7 : { t1: boolean; t2: string; }
 >temp : { t1: boolean; t2: string; }

tests/baselines/reference/destructuringVariableDeclaration1ES6.types

@@ -46,7 +46,7 @@ var temp = { t1: true, t2: "false" };
 >"false" : "false"
 
 var [b2 = 3, b3 = true, b4 = temp] = [3, false, { t1: false, t2: "hello" }];
->b2 : number
+>b2 : 3
 >3 : 3
 >b3 : boolean
 >true : true
@@ -62,9 +62,9 @@ var [b2 = 3, b3 = true, b4 = temp] = [3, false, { t1: false, t2: "hello" }];
 >"hello" : "hello"
 
 var [b5 = 3, b6 = true, b7 = temp] = [undefined, undefined, undefined];
->b5 : number
+>b5 : 3
 >3 : 3
->b6 : boolean
+>b6 : true
 >true : true
 >b7 : { t1: boolean; t2: string; }
 >temp : { t1: boolean; t2: string; }

tests/baselines/reference/destructuringVariableDeclaration2.types

@@ -34,7 +34,7 @@ var temp = { t1: true, t2: "false" };
 >"false" : "false"
 
 var [b0 = 3, b1 = true, b2 = temp] = [3, false, { t1: false, t2: 5}];  // Error
->b0 : number
+>b0 : 3
 >3 : 3
 >b1 : boolean
 >true : true

tests/baselines/reference/emitArrowFunctionES6.types

@@ -90,7 +90,7 @@ var p9 = ({ a: { b = 1 } = { b: 1 } }) => { };
 >p9 : ({ a: { b } }: { a?: { b?: 1; }; }) => void
 >({ a: { b = 1 } = { b: 1 } }) => { } : ({ a: { b } }: { a?: { b?: 1; }; }) => void
 >a : any
->b : number
+>b : 1
 >1 : 1
 >{ b: 1 } : { b?: 1; }
 >b : number

tests/baselines/reference/for-of43.types

@@ -13,7 +13,7 @@ for (var {x: a = "", y: b = true} of array) {
 >a : string
 >"" : ""
 >y : any
->b : number | boolean
+>b : number | true
 >true : true
 >array : { x: string; y: number; }[]
 

tests/baselines/reference/literalTypes2.types

@@ -497,9 +497,9 @@ function f6() {
     let { x1 = true, x2 = 0, x3 = "foo" } = { x1: false, x2: 1, x3: "bar" };
 >x1 : boolean
 >true : true
->x2 : number
+>x2 : 1 | 0
 >0 : 0
->x3 : string
+>x3 : "foo" | "bar"
 >"foo" : "foo"
 >{ x1: false, x2: 1, x3: "bar" } : { x1?: false; x2?: 1; x3?: "bar"; }
 >x1 : boolean

tests/baselines/reference/literalTypesAndTypeAssertions.types

@@ -29,7 +29,7 @@ let x2 = 1;
 >1 : 1
 
 let { a = "foo" } = { a: "foo" };
->a : string
+>a : "foo"
 >"foo" : "foo"
 >{ a: "foo" } : { a?: "foo"; }
 >a : string
@@ -44,7 +44,7 @@ let { b = "foo" as "foo" } = { b: "bar" };
 >"bar" : "bar"
 
 let { c = "foo" } = { c: "bar" as "bar" };
->c : string
+>c : "foo" | "bar"
 >"foo" : "foo"
 >{ c: "bar" as "bar" } : { c?: "bar"; }
 >c : "bar"

tests/baselines/reference/noImplicitAnyDestructuringVarDeclaration2.types

@@ -9,11 +9,11 @@ let [a, b, c] = [1, 2, 3]; // no error
 >3 : 3
 
 let [a1 = 10, b1 = 10, c1 = 10] = [1, 2, 3]; // no error
->a1 : number
+>a1 : 1 | 10
 >10 : 10
->b1 : number
+>b1 : 2 | 10
 >10 : 10
->c1 : number
+>c1 : 3 | 10
 >10 : 10
 >[1, 2, 3] : [1, 2, 3]
 >1 : 1
@@ -76,11 +76,11 @@ let {x, y, z} = { x: 1, y: 2, z: 3 }; // no error
 >3 : 3
 
 let {x1 = 10, y1 = 10, z1 = 10} = { x1: 1, y1: 2, z1: 3 }; // no error
->x1 : number
+>x1 : 1 | 10
 >10 : 10
->y1 : number
+>y1 : 2 | 10
 >10 : 10
->z1 : number
+>z1 : 3 | 10
 >10 : 10
 >{ x1: 1, y1: 2, z1: 3 } : { x1?: 1; y1?: 2; z1?: 3; }
 >x1 : number

tests/baselines/reference/shadowingViaLocalValueOrBindingElement.errors.txt

@@ -1,11 +1,13 @@
 tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(4,13): error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
+tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(5,15): error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type 'number' at tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts 3:12, but here has type '0'.
 tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(5,15): error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
+tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(6,18): error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type 'number' at tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts 3:12, but here has type '0'.
 tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(6,18): error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
 tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(7,15): error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
 tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(8,18): error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
 
 
-==== tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts (5 errors) ====
+==== tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts (7 errors) ====
     if (true) {
         let x;
         if (true) {
@@ -14,9 +16,13 @@ tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts(8,18): error TS24
 !!! error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
             var { x = 0 } = { x: 0 }; // Error
                   ~
+!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type 'number' at tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts 3:12, but here has type '0'.
+                  ~
 !!! error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
             var { x: x = 0 } = { x: 0 }; // Error
                      ~
+!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'x' has type 'number' at tests/cases/compiler/shadowingViaLocalValueOrBindingElement.ts 3:12, but here has type '0'.
+                     ~
 !!! error TS2481: Cannot initialize outer scoped variable 'x' in the same scope as block scoped declaration 'x'.
             var { x } = { x: 0 }; // Error
                   ~