diff --git a/src/lib/es2015.core.d.ts b/src/lib/es2015.core.d.ts
index 3b1c76c5afc3c..5c0a6ac3930e9 100644
--- a/src/lib/es2015.core.d.ts
+++ b/src/lib/es2015.core.d.ts
@@ -38,10 +38,10 @@ interface Array<T> {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 }
 
 interface ArrayConstructor {
diff --git a/src/lib/es2020.bigint.d.ts b/src/lib/es2020.bigint.d.ts
index e13da87bc71c7..a39c9056132dc 100644
--- a/src/lib/es2020.bigint.d.ts
+++ b/src/lib/es2020.bigint.d.ts
@@ -147,10 +147,10 @@ interface BigInt64Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /** Yields index, value pairs for every entry in the array. */
     entries(): IterableIterator<[number, bigint]>;
@@ -419,10 +419,10 @@ interface BigUint64Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /** Yields index, value pairs for every entry in the array. */
     entries(): IterableIterator<[number, bigint]>;
diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index a74b3cb4c2111..29d414ffb5d1e 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -1849,10 +1849,10 @@ interface Int8Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -2131,10 +2131,10 @@ interface Uint8Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -2413,10 +2413,10 @@ interface Uint8ClampedArray {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -2694,10 +2694,10 @@ interface Int16Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -2976,10 +2976,10 @@ interface Uint16Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -3258,10 +3258,10 @@ interface Int32Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -3540,10 +3540,10 @@ interface Uint32Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -3821,10 +3821,10 @@ interface Float32Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
@@ -4104,10 +4104,10 @@ interface Float64Array {
      * @param target If target is negative, it is treated as length+target where length is the
      * length of the array.
      * @param start If start is negative, it is treated as length+start. If end is negative, it
-     * is treated as length+end.
+     * is treated as length+end. If start is omitted, `0` is used.
      * @param end If not specified, length of the this object is used as its default value.
      */
-    copyWithin(target: number, start: number, end?: number): this;
+    copyWithin(target: number, start?: number, end?: number): this;
 
     /**
      * Determines whether all the members of an array satisfy the specified test.
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.errors.txt b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.errors.txt
index f12c21d1de942..afaf26aa35ada 100644
--- a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.errors.txt
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts(3,1): error TS2741: Property 'length' is missing in type '{ [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }' but required in type 'number[]'.
+tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts(3,1): error TS2741: Property 'length' is missing in type '{ [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }' but required in type 'number[]'.
 
 
 ==== tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts (1 errors) ====
@@ -6,6 +6,6 @@ tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty.ts(3,1): error T
     declare let src2: { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] };
     tgt2 = src2; // Should error
     ~~~~
-!!! error TS2741: Property 'length' is missing in type '{ [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }' but required in type 'number[]'.
+!!! error TS2741: Property 'length' is missing in type '{ [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }' but required in type 'number[]'.
 !!! related TS2728 /.ts/lib.es5.d.ts:--:--: 'length' is declared here.
     
\ No newline at end of file
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.types b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.types
index 393ef58cbab5b..2cc033d0d6f58 100644
--- a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.types
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty.types
@@ -3,10 +3,10 @@ declare let tgt2: number[];
 >tgt2 : number[]
 
 declare let src2: { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] };
->src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
+>src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
 
 tgt2 = src2; // Should error
->tgt2 = src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
+>tgt2 = src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
 >tgt2 : number[]
->src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
+>src2 : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
 
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.js b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.js
index cf4345099057c..8322df4594407 100644
--- a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.js
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.js
@@ -56,7 +56,7 @@ export declare const thing: {
     };
     findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number;
     fill: (value: number, start?: number, end?: number) => number[];
-    copyWithin: (target: number, start: number, end?: number) => number[];
+    copyWithin: (target: number, start?: number, end?: number) => number[];
     entries: () => IterableIterator<[number, number]>;
     keys: () => IterableIterator<number>;
     values: () => IterableIterator<number>;
@@ -162,7 +162,7 @@ tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.d.ts(24,118): e
         };
         findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number;
         fill: (value: number, start?: number, end?: number) => number[];
-        copyWithin: (target: number, start: number, end?: number) => number[];
+        copyWithin: (target: number, start?: number, end?: number) => number[];
         entries: () => IterableIterator<[number, number]>;
         keys: () => IterableIterator<number>;
         values: () => IterableIterator<number>;
diff --git a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.types b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.types
index 7742d430312c5..388700b19798e 100644
--- a/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.types
+++ b/tests/baselines/reference/mappedTypeWithAsClauseAndLateBoundProperty2.types
@@ -1,7 +1,7 @@
 === tests/cases/compiler/mappedTypeWithAsClauseAndLateBoundProperty2.ts ===
 export const thing = (null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] });
->thing : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
->(null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] }) : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
->null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] } : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
+>thing : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
+>(null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] }) : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
+>null as any as { [K in keyof number[] as Exclude<K, "length">]: (number[])[K] } : { [x: number]: number; toString: () => string; toLocaleString: () => string; pop: () => number; push: (...items: number[]) => number; concat: { (...items: ConcatArray<number>[]): number[]; (...items: (number | ConcatArray<number>)[]): number[]; }; join: (separator?: string) => string; reverse: () => number[]; shift: () => number; slice: (start?: number, end?: number) => number[]; sort: (compareFn?: (a: number, b: number) => number) => number[]; splice: { (start: number, deleteCount?: number): number[]; (start: number, deleteCount: number, ...items: number[]): number[]; }; unshift: (...items: number[]) => number; indexOf: (searchElement: number, fromIndex?: number) => number; lastIndexOf: (searchElement: number, fromIndex?: number) => number; every: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): this is S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): boolean; }; some: (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean; forEach: (callbackfn: (value: number, index: number, array: number[]) => void, thisArg?: any) => void; map: <U>(callbackfn: (value: number, index: number, array: number[]) => U, thisArg?: any) => U[]; filter: { <S extends number>(predicate: (value: number, index: number, array: number[]) => value is S, thisArg?: any): S[]; (predicate: (value: number, index: number, array: number[]) => unknown, thisArg?: any): number[]; }; 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; }; reduceRight: { (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; }; find: { <S extends number>(predicate: (value: number, index: number, obj: number[]) => value is S, thisArg?: any): S; (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any): number; }; findIndex: (predicate: (value: number, index: number, obj: number[]) => unknown, thisArg?: any) => number; fill: (value: number, start?: number, end?: number) => number[]; copyWithin: (target: number, start?: number, end?: number) => number[]; entries: () => IterableIterator<[number, number]>; keys: () => IterableIterator<number>; values: () => IterableIterator<number>; includes: (searchElement: number, fromIndex?: number) => boolean; flatMap: <U, This = undefined>(callback: (this: This, value: number, index: number, array: number[]) => U | readonly U[], thisArg?: This) => U[]; flat: <A, D extends number = 1>(this: A, depth?: D) => FlatArray<A, D>[]; [Symbol.iterator]: () => IterableIterator<number>; readonly [Symbol.unscopables]: { [x: number]: boolean; length?: boolean; toString?: boolean; toLocaleString?: boolean; pop?: boolean; push?: boolean; concat?: boolean; join?: boolean; reverse?: boolean; shift?: boolean; slice?: boolean; sort?: boolean; splice?: boolean; unshift?: boolean; indexOf?: boolean; lastIndexOf?: boolean; every?: boolean; some?: boolean; forEach?: boolean; map?: boolean; filter?: boolean; reduce?: boolean; reduceRight?: boolean; find?: boolean; findIndex?: boolean; fill?: boolean; copyWithin?: boolean; entries?: boolean; keys?: boolean; values?: boolean; includes?: boolean; flatMap?: boolean; flat?: boolean; [Symbol.iterator]?: boolean; readonly [Symbol.unscopables]?: boolean; }; }
 >null as any : any