microsoft · ahejlsberg · Jul 15, 2024 · Jul 4, 2024 · Jul 4, 2024 · Jul 4, 2024
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
@@ -2680,10 +2680,6 @@
         "category": "Error",
         "code": 2524
     },
-    "Initializer provides no value for this binding element and the binding element has no default value.": {
-        "category": "Error",
-        "code": 2525
-    },
     "A 'this' type is available only in a non-static member of a class or interface.": {
         "category": "Error",
         "code": 2526

diff --git a/src/compiler/types.ts b/src/compiler/types.ts
@@ -6693,7 +6693,7 @@ export const enum AccessFlags {
     NoIndexSignatures = 1 << 1,
     Writing = 1 << 2,
     CacheSymbol = 1 << 3,
-    NoTupleBoundsCheck = 1 << 4,
+    AllowMissing = 1 << 4,
     ExpressionPosition = 1 << 5,
     ReportDeprecated = 1 << 6,
     SuppressNoImplicitAnyError = 1 << 7,

diff --git a/tests/baselines/reference/checkDestructuringShorthandAssigment.types b/tests/baselines/reference/checkDestructuringShorthandAssigment.types
@@ -9,24 +9,24 @@ function Test({ b = '' } = {}) {}
 >  : ^^^^^^
 >'' : ""
 >   : ^^
->{} : { b?: string; }
->   : ^^^^^^^^^^^^^^^
+>{} : {}
+>   : ^^
 
 Test(({ b = '5' } = {}));
 >Test(({ b = '5' } = {})) : void
 >                         : ^^^^
 >Test : ({ b }?: { b?: string; }) => void
 >     : ^     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
->({ b = '5' } = {}) : { b?: any; }
->                   : ^^^^^^^^^^^^
->{ b = '5' } = {} : { b?: any; }
->                 : ^^^^^^^^^^^^
+>({ b = '5' } = {}) : {}
+>                   : ^^
+>{ b = '5' } = {} : {}
+>                 : ^^
 >{ b = '5' } : { b?: any; }
 >            : ^^^^^^^^^^^^
 >b : any
 >  : ^^^
 >'5' : "5"
 >    : ^^^
->{} : { b?: any; }
->   : ^^^^^^^^^^^^
+>{} : {}
+>   : ^^
 
diff --git a/tests/baselines/reference/checkDestructuringShorthandAssigment2.errors.txt b/tests/baselines/reference/checkDestructuringShorthandAssigment2.errors.txt
@@ -1,14 +1,11 @@
-checkDestructuringShorthandAssigment2.ts(4,7): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 checkDestructuringShorthandAssigment2.ts(4,27): error TS2353: Object literal may only specify known properties, and '[k]' does not exist in type '{ x: any; }'.
 
 
-==== checkDestructuringShorthandAssigment2.ts (2 errors) ====
+==== checkDestructuringShorthandAssigment2.ts (1 errors) ====
     // GH #38175 -- should not crash while checking
 
     let o: any, k: any;
     let { x } = { x: 1, ...o, [k]: 1 };
-          ~
-!!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
                               ~~~
 !!! error TS2353: Object literal may only specify known properties, and '[k]' does not exist in type '{ x: any; }'.
 
diff --git a/tests/baselines/reference/circularReferenceInReturnType2.types b/tests/baselines/reference/circularReferenceInReturnType2.types
@@ -104,8 +104,8 @@ type Something = { foo: number };
 
 // inference fails here, but ideally should not
 const A = object<Something>()({
->A : ObjectType<Something>
->  : ^^^^^^^^^^^^^^^^^^^^^
+>A : any
+>  : ^^^
 >object<Something>()({  name: "A",  fields: () => ({    a: field({      type: A,      resolve() {        return {          foo: 100,        };      },    }),  }),}) : ObjectType<Something>
 >                                                                                                                                                                    : ^^^^^^^^^^^^^^^^^^^^^
 >object<Something>() : <Fields extends { [Key in keyof Fields]: Field<Something, Key & string>; }>(config: { name: string; fields: Fields | (() => Fields); }) => ObjectType<Something>
@@ -138,14 +138,14 @@ const A = object<Something>()({
 >                                                                                                  : ^^^^^^^^^^^^^^^^^^^^^
 >field : <Source, Type extends ObjectType<any>, Key extends string>(field: FieldFuncArgs<Source, Type>) => Field<Source, Key>
 >      : ^      ^^    ^^^^^^^^^               ^^   ^^^^^^^^^      ^^     ^^                           ^^^^^                  
->{      type: A,      resolve() {        return {          foo: 100,        };      },    } : { type: ObjectType<Something>; resolve(): { foo: number; }; }
->                                                                                           : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{      type: A,      resolve() {        return {          foo: 100,        };      },    } : { type: any; resolve(): { foo: number; }; }
+>                                                                                           : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
       type: A,
->type : ObjectType<Something>
->     : ^^^^^^^^^^^^^^^^^^^^^
->A : ObjectType<Something>
->  : ^^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
+>A : any
+>  : ^^^
 
       resolve() {
 >resolve : () => { foo: number; }

diff --git a/tests/baselines/reference/contextualTypeForInitalizedVariablesFiltersUndefined.types b/tests/baselines/reference/contextualTypeForInitalizedVariablesFiltersUndefined.types
@@ -10,8 +10,8 @@ const fInferred = ({ a = 0 } = {}) => a;
 >  : ^^^^^^
 >0 : 0
 >  : ^
->{} : { a?: number | undefined; }
->   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{} : {}
+>   : ^^
 >a : number
 >  : ^^^^^^
 

diff --git a/tests/baselines/reference/controlFlowDestructuringVariablesInTryCatch.types b/tests/baselines/reference/controlFlowDestructuringVariablesInTryCatch.types
@@ -53,8 +53,8 @@ try {
 >  : ^^^^^^
 >1 : 1
 >  : ^
->{ } : { e?: number | undefined; }
->    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{ } : {}
+>    : ^^
 
 } catch {
     console.error("error");

diff --git a/tests/baselines/reference/declarationsAndAssignments.errors.txt b/tests/baselines/reference/declarationsAndAssignments.errors.txt
@@ -11,8 +11,8 @@ declarationsAndAssignments.ts(63,13): error TS2493: Tuple type '[number]' of len
 declarationsAndAssignments.ts(63,16): error TS2493: Tuple type '[number]' of length '1' has no element at index '2'.
 declarationsAndAssignments.ts(67,9): error TS2461: Type '{}' is not an array type.
 declarationsAndAssignments.ts(68,9): error TS2461: Type '{ 0: number; 1: number; }' is not an array type.
-declarationsAndAssignments.ts(73,11): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
-declarationsAndAssignments.ts(73,14): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+declarationsAndAssignments.ts(73,11): error TS2339: Property 'a' does not exist on type '{}'.
+declarationsAndAssignments.ts(73,14): error TS2339: Property 'b' does not exist on type '{}'.
 declarationsAndAssignments.ts(74,11): error TS2339: Property 'a' does not exist on type 'undefined[]'.
 declarationsAndAssignments.ts(74,14): error TS2339: Property 'b' does not exist on type 'undefined[]'.
 declarationsAndAssignments.ts(106,17): error TS2741: Property 'x' is missing in type '{ y: false; }' but required in type '{ x: any; y?: boolean; }'.
@@ -122,9 +122,9 @@ declarationsAndAssignments.ts(138,9): error TS2322: Type 'number' is not assigna
     function f10() {
         var { a, b } = {};  // Error
               ~
-!!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+!!! error TS2339: Property 'a' does not exist on type '{}'.
                  ~
-!!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+!!! error TS2339: Property 'b' does not exist on type '{}'.
         var { a, b } = [];  // Error
               ~
 !!! error TS2339: Property 'a' does not exist on type 'undefined[]'.

diff --git a/tests/baselines/reference/declarationsAndAssignments.types b/tests/baselines/reference/declarationsAndAssignments.types
@@ -486,8 +486,8 @@ function f10() {
 >  : ^^^
 >b : any
 >  : ^^^
->{} : { a: any; b: any; }
->   : ^^^^^^^^^^^^^^^^^^^
+>{} : {}
+>   : ^^
 
     var { a, b } = [];  // Error
 >a : any

diff --git a/tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.errors.txt b/tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.errors.txt
@@ -1,4 +1,4 @@
-destructuredLateBoundNameHasCorrectTypes.ts(11,21): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+destructuredLateBoundNameHasCorrectTypes.ts(11,8): error TS2339: Property 'prop2' does not exist on type '{ prop: string; }'.
 destructuredLateBoundNameHasCorrectTypes.ts(11,37): error TS2353: Object literal may only specify known properties, and 'prop' does not exist in type '{ prop2: any; }'.
 
 
@@ -14,8 +14,8 @@ destructuredLateBoundNameHasCorrectTypes.ts(11,37): error TS2353: Object literal
     const notPresent = "prop2";
 
     let { [notPresent]: computed2 } = { prop: "b" };
-                        ~~~~~~~~~
-!!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+           ~~~~~~~~~~
+!!! error TS2339: Property 'prop2' does not exist on type '{ prop: string; }'.
                                         ~~~~
 !!! error TS2353: Object literal may only specify known properties, and 'prop' does not exist in type '{ prop2: any; }'.
 
diff --git a/tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.types b/tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.types
@@ -54,8 +54,8 @@ let { [notPresent]: computed2 } = { prop: "b" };
 >           : ^^^^^^^
 >computed2 : any
 >          : ^^^
->{ prop: "b" } : { prop: string; prop2: any; }
->              : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{ prop: "b" } : { prop: string; }
+>              : ^^^^^^^^^^^^^^^^^
 >prop : string
 >     : ^^^^^^
 >"b" : "b"

diff --git a/tests/baselines/reference/destructuringArrayBindingPatternAndAssignment3.types b/tests/baselines/reference/destructuringArrayBindingPatternAndAssignment3.types
@@ -30,20 +30,20 @@ const [c, d = c, e = e] = [1]; // error for e = e
 >  : ^
 
 const [f, g = f, h = i, i = f] = [1]; // error for h = i
->f : any
->  : ^^^
->g : any
->  : ^^^
->f : any
->  : ^^^
->h : any
->  : ^^^
->i : any
->  : ^^^
->i : any
->  : ^^^
->f : any
->  : ^^^
+>f : number
+>  : ^^^^^^
+>g : number
+>  : ^^^^^^
+>f : number
+>  : ^^^^^^
+>h : number
+>  : ^^^^^^
+>i : number
+>  : ^^^^^^
+>i : number
+>  : ^^^^^^
+>f : number
+>  : ^^^^^^
 >[1] : [number]
 >    : ^^^^^^^^
 >1 : 1

diff --git a/tests/baselines/reference/destructuringFromUnionSpread.errors.txt b/tests/baselines/reference/destructuringFromUnionSpread.errors.txt
@@ -1,4 +1,4 @@
-destructuringFromUnionSpread.ts(5,9): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+destructuringFromUnionSpread.ts(5,9): error TS2339: Property 'a' does not exist on type '{ a: string; } | { b: number; }'.
 
 
 ==== destructuringFromUnionSpread.ts (1 errors) ====
@@ -8,5 +8,5 @@ destructuringFromUnionSpread.ts(5,9): error TS2525: Initializer provides no valu
     declare const x: A | B;
     const { a } = { ...x } // error
             ~
-!!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+!!! error TS2339: Property 'a' does not exist on type '{ a: string; } | { b: number; }'.
 
diff --git a/tests/baselines/reference/destructuringFromUnionSpread.types b/tests/baselines/reference/destructuringFromUnionSpread.types
@@ -16,8 +16,8 @@ declare const x: A | B;
 const { a } = { ...x } // error
 >a : any
 >  : ^^^
->{ ...x } : { a: any; } | { a: any; b: number; }
->         : ^^^^^^^^^^^^^^^^^^^^^^^^^^^      ^^^
+>{ ...x } : { a: string; } | { b: number; }
+>         : ^^^^^      ^^^^^^^^^^^      ^^^
 >x : A | B
 >  : ^^^^^
 
diff --git a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.errors.txt b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.errors.txt
@@ -2,14 +2,13 @@ destructuringObjectBindingPatternAndAssignment3.ts(2,7): error TS1005: ',' expec
 destructuringObjectBindingPatternAndAssignment3.ts(3,5): error TS2322: Type '{ i: number; }' is not assignable to type 'string | number'.
 destructuringObjectBindingPatternAndAssignment3.ts(3,6): error TS2339: Property 'i' does not exist on type 'string | number'.
 destructuringObjectBindingPatternAndAssignment3.ts(4,6): error TS2339: Property 'i1' does not exist on type 'string | number | {}'.
-destructuringObjectBindingPatternAndAssignment3.ts(5,12): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 destructuringObjectBindingPatternAndAssignment3.ts(5,21): error TS2353: Object literal may only specify known properties, and 'f212' does not exist in type '{ f21: any; }'.
 destructuringObjectBindingPatternAndAssignment3.ts(6,7): error TS1005: ':' expected.
 destructuringObjectBindingPatternAndAssignment3.ts(6,15): error TS1005: ':' expected.
 destructuringObjectBindingPatternAndAssignment3.ts(7,12): error TS1005: ':' expected.
 
 
-==== destructuringObjectBindingPatternAndAssignment3.ts (9 errors) ====
+==== destructuringObjectBindingPatternAndAssignment3.ts (8 errors) ====
     // Error
     var {h?} = { h?: 1 };
           ~
@@ -23,8 +22,6 @@ destructuringObjectBindingPatternAndAssignment3.ts(7,12): error TS1005: ':' expe
          ~~
 !!! error TS2339: Property 'i1' does not exist on type 'string | number | {}'.
     var { f2: {f21} = { f212: "string" } }: any = undefined;
-               ~~~
-!!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
                         ~~~~
 !!! error TS2353: Object literal may only specify known properties, and 'f212' does not exist in type '{ f21: any; }'.
     var {1} = { 1 };

diff --git a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.types b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment3.types
@@ -37,8 +37,8 @@ var { f2: {f21} = { f212: "string" } }: any = undefined;
 >   : ^^^
 >f21 : any
 >    : ^^^
->{ f212: "string" } : { f212: string; f21: any; }
->                   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{ f212: "string" } : { f212: string; }
+>                   : ^^^^^^^^^^^^^^^^^
 >f212 : string
 >     : ^^^^^^
 >"string" : "string"

diff --git a/...selines/reference/destructuringObjectBindingPatternAndAssignment9SiblingInitializer.types b/...selines/reference/destructuringObjectBindingPatternAndAssignment9SiblingInitializer.types
@@ -13,8 +13,8 @@ function f1() {
 >   : ^^^^^^
 >a1 : number
 >   : ^^^^^^
->{ a1: 1 } : { a1: number; b1?: number; }
->          : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{ a1: 1 } : { a1: number; }
+>          : ^^^^^^^^^^^^^^^
 >a1 : number
 >   : ^^^^^^
 >1 : 1
@@ -31,8 +31,8 @@ function f1() {
 >  : ^
 >a2 : number
 >   : ^^^^^^
->{ a2: 1 } : { a2: number; b2?: number; }
->          : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{ a2: 1 } : { a2: number; }
+>          : ^^^^^^^^^^^^^^^
 >a2 : number
 >   : ^^^^^^
 >1 : 1
@@ -51,8 +51,8 @@ function f2() {
 >   : ^^^^^^
 >a1 : string
 >   : ^^^^^^
->{ a1: 'hi' } : { a1: string; b1?: string; }
->             : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{ a1: 'hi' } : { a1: string; }
+>             : ^^^^^^^^^^^^^^^
 >a1 : string
 >   : ^^^^^^
 >'hi' : "hi"
@@ -69,8 +69,8 @@ function f2() {
 >   : ^^^^^^
 >'!' : "!"
 >    : ^^^
->{ a2: 'hi' } : { a2: string; b2?: string; }
->             : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{ a2: 'hi' } : { a2: string; }
+>             : ^^^^^^^^^^^^^^^
 >a2 : string
 >   : ^^^^^^
 >'hi' : "hi"

diff --git a/tests/baselines/reference/destructuringSpread.errors.txt b/tests/baselines/reference/destructuringSpread.errors.txt
@@ -1,4 +1,4 @@
-destructuringSpread.ts(16,21): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+destructuringSpread.ts(16,21): error TS2339: Property 'g' does not exist on type '{ f: number; e: number; d: number; c: number; }'.
 
 
 ==== destructuringSpread.ts (1 errors) ====
@@ -19,7 +19,7 @@ destructuringSpread.ts(16,21): error TS2525: Initializer provides no value for t
 
     const { c, d, e, f, g } = {
                         ~
-!!! error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
+!!! error TS2339: Property 'g' does not exist on type '{ f: number; e: number; d: number; c: number; }'.
       ...{
         ...{
           ...{

diff --git a/tests/baselines/reference/destructuringSpread.types b/tests/baselines/reference/destructuringSpread.types
@@ -78,8 +78,8 @@ const { c, d, e, f, g } = {
 >  : ^^^^^^
 >g : any
 >  : ^^^
->{  ...{    ...{      ...{        c: 0,      },      d: 0    },    e: 0  },  f: 0} : { f: number; g: any; e: number; d: number; c: number; }
->                                                                                  : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>{  ...{    ...{      ...{        c: 0,      },      d: 0    },    e: 0  },  f: 0} : { f: number; e: number; d: number; c: number; }
+>                                                                                  : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
   ...{
 >{    ...{      ...{        c: 0,      },      d: 0    },    e: 0  } : { e: number; d: number; c: number; }