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fix: [Symbol.iterator]() lost on union with never
#62661
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ba03419
test: iterable with type reducible to never as union member
nrainhart 20bd02d
fix: exclude union members reducible to 'never' when searching iterator
nrainhart 93fb716
reduce the whole iterable-like type instead of the union members
nrainhart a0a3bb4
refactor: rename reducedType var in getIterationTypesOfIterable to type
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83 changes: 83 additions & 0 deletions
83
tests/baselines/reference/iterableWithNeverAsUnionMember(target=es5).symbols
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,83 @@ | ||
| //// [tests/cases/compiler/iterableWithNeverAsUnionMember.ts] //// | ||
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| === iterableWithNeverAsUnionMember.ts === | ||
| declare const o1: { a: "foo" } & { a: "bar" }; | ||
| >o1 : Symbol(o1, Decl(iterableWithNeverAsUnionMember.ts, 0, 13)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 0, 19)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 0, 34)) | ||
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| const [el1] = o1; // error | ||
| >el1 : Symbol(el1, Decl(iterableWithNeverAsUnionMember.ts, 1, 7)) | ||
| >o1 : Symbol(o1, Decl(iterableWithNeverAsUnionMember.ts, 0, 13)) | ||
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| // https://github.com/microsoft/TypeScript/issues/62462 | ||
| declare var x: number[] | ({ t: "a" } & { t: "b" }); | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 4, 11)) | ||
| >t : Symbol(t, Decl(iterableWithNeverAsUnionMember.ts, 4, 28)) | ||
| >t : Symbol(t, Decl(iterableWithNeverAsUnionMember.ts, 4, 41)) | ||
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| let [el2] = x; // ok | ||
| >el2 : Symbol(el2, Decl(iterableWithNeverAsUnionMember.ts, 5, 5)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 4, 11)) | ||
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| for (const elem of x) { // ok | ||
| >elem : Symbol(elem, Decl(iterableWithNeverAsUnionMember.ts, 7, 10)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 4, 11)) | ||
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| elem.toFixed(); | ||
| >elem.toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --)) | ||
| >elem : Symbol(elem, Decl(iterableWithNeverAsUnionMember.ts, 7, 10)) | ||
| >toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --)) | ||
| } | ||
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| type Shape = | ||
| >Shape : Symbol(Shape, Decl(iterableWithNeverAsUnionMember.ts, 9, 1)) | ||
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| | { kind: "circle"; radius: number } | ||
| >kind : Symbol(kind, Decl(iterableWithNeverAsUnionMember.ts, 12, 5)) | ||
| >radius : Symbol(radius, Decl(iterableWithNeverAsUnionMember.ts, 12, 21)) | ||
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| | { kind: "rectangle"; width: number; height: number }; | ||
| >kind : Symbol(kind, Decl(iterableWithNeverAsUnionMember.ts, 13, 5)) | ||
| >width : Symbol(width, Decl(iterableWithNeverAsUnionMember.ts, 13, 24)) | ||
| >height : Symbol(height, Decl(iterableWithNeverAsUnionMember.ts, 13, 39)) | ||
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| type Circle = Shape & { kind: "circle" }; | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
| >Shape : Symbol(Shape, Decl(iterableWithNeverAsUnionMember.ts, 9, 1)) | ||
| >kind : Symbol(kind, Decl(iterableWithNeverAsUnionMember.ts, 15, 23)) | ||
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| function doStuffWithCircle(arg: Circle | [Circle, (newValue: Circle) => void]) { | ||
| >doStuffWithCircle : Symbol(doStuffWithCircle, Decl(iterableWithNeverAsUnionMember.ts, 15, 41)) | ||
| >arg : Symbol(arg, Decl(iterableWithNeverAsUnionMember.ts, 17, 27)) | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
| >newValue : Symbol(newValue, Decl(iterableWithNeverAsUnionMember.ts, 17, 51)) | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
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| if (Array.isArray(arg)) { | ||
| >Array.isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --)) | ||
| >Array : Symbol(Array, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --)) | ||
| >isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --)) | ||
| >arg : Symbol(arg, Decl(iterableWithNeverAsUnionMember.ts, 17, 27)) | ||
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| let [value, setValue] = arg; // ok | ||
| >value : Symbol(value, Decl(iterableWithNeverAsUnionMember.ts, 19, 9)) | ||
| >setValue : Symbol(setValue, Decl(iterableWithNeverAsUnionMember.ts, 19, 15)) | ||
| >arg : Symbol(arg, Decl(iterableWithNeverAsUnionMember.ts, 17, 27)) | ||
| } | ||
| } | ||
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| function f1<T extends { a: "foo" } & { a: "bar" }>(x: T) { | ||
| >f1 : Symbol(f1, Decl(iterableWithNeverAsUnionMember.ts, 21, 1)) | ||
| >T : Symbol(T, Decl(iterableWithNeverAsUnionMember.ts, 23, 12)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 23, 23)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 23, 38)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 23, 51)) | ||
| >T : Symbol(T, Decl(iterableWithNeverAsUnionMember.ts, 23, 12)) | ||
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| let [y] = x; // error | ||
| >y : Symbol(y, Decl(iterableWithNeverAsUnionMember.ts, 24, 7)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 23, 51)) | ||
| } | ||
|
|
120 changes: 120 additions & 0 deletions
120
tests/baselines/reference/iterableWithNeverAsUnionMember(target=es5).types
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,120 @@ | ||
| //// [tests/cases/compiler/iterableWithNeverAsUnionMember.ts] //// | ||
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| === iterableWithNeverAsUnionMember.ts === | ||
| declare const o1: { a: "foo" } & { a: "bar" }; | ||
| >o1 : never | ||
| > : ^^^^^ | ||
| >a : "foo" | ||
| > : ^^^^^ | ||
| >a : "bar" | ||
| > : ^^^^^ | ||
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| const [el1] = o1; // error | ||
| >el1 : never | ||
| > : ^^^^^ | ||
| >o1 : never | ||
| > : ^^^^^ | ||
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| // https://github.com/microsoft/TypeScript/issues/62462 | ||
| declare var x: number[] | ({ t: "a" } & { t: "b" }); | ||
| >x : number[] | ||
| > : ^^^^^^^^ | ||
| >t : "a" | ||
| > : ^^^ | ||
| >t : "b" | ||
| > : ^^^ | ||
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| let [el2] = x; // ok | ||
| >el2 : number | ||
| > : ^^^^^^ | ||
| >x : number[] | ||
| > : ^^^^^^^^ | ||
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| for (const elem of x) { // ok | ||
| >elem : number | ||
| > : ^^^^^^ | ||
| >x : number[] | ||
| > : ^^^^^^^^ | ||
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| elem.toFixed(); | ||
| >elem.toFixed() : string | ||
| > : ^^^^^^ | ||
| >elem.toFixed : (fractionDigits?: number) => string | ||
| > : ^ ^^^ ^^^^^ | ||
| >elem : number | ||
| > : ^^^^^^ | ||
| >toFixed : (fractionDigits?: number) => string | ||
| > : ^ ^^^ ^^^^^ | ||
| } | ||
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| type Shape = | ||
| >Shape : Shape | ||
| > : ^^^^^ | ||
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| | { kind: "circle"; radius: number } | ||
| >kind : "circle" | ||
| > : ^^^^^^^^ | ||
| >radius : number | ||
| > : ^^^^^^ | ||
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| | { kind: "rectangle"; width: number; height: number }; | ||
| >kind : "rectangle" | ||
| > : ^^^^^^^^^^^ | ||
| >width : number | ||
| > : ^^^^^^ | ||
| >height : number | ||
| > : ^^^^^^ | ||
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| type Circle = Shape & { kind: "circle" }; | ||
| >Circle : { kind: "circle"; radius: number; } & { kind: "circle"; } | ||
| > : ^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^ | ||
| >kind : "circle" | ||
| > : ^^^^^^^^ | ||
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| function doStuffWithCircle(arg: Circle | [Circle, (newValue: Circle) => void]) { | ||
| >doStuffWithCircle : (arg: Circle | [Circle, (newValue: Circle) => void]) => void | ||
| > : ^ ^^ ^^^^^^^^^ | ||
| >arg : ({ kind: "circle"; radius: number; } & { kind: "circle"; }) | [{ kind: "circle"; radius: number; } & { kind: "circle"; }, (newValue: Circle) => void] | ||
| > : ^^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^ ^^ ^^^^^ ^ | ||
| >newValue : { kind: "circle"; radius: number; } & { kind: "circle"; } | ||
| > : ^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^ | ||
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| if (Array.isArray(arg)) { | ||
| >Array.isArray(arg) : boolean | ||
| > : ^^^^^^^ | ||
| >Array.isArray : (arg: any) => arg is any[] | ||
| > : ^ ^^ ^^^^^ | ||
| >Array : ArrayConstructor | ||
| > : ^^^^^^^^^^^^^^^^ | ||
| >isArray : (arg: any) => arg is any[] | ||
| > : ^ ^^ ^^^^^ | ||
| >arg : ({ kind: "circle"; radius: number; } & { kind: "circle"; }) | [{ kind: "circle"; radius: number; } & { kind: "circle"; }, (newValue: Circle) => void] | ||
| > : ^^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^ ^^ ^^^^^ ^ | ||
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| let [value, setValue] = arg; // ok | ||
| >value : { kind: "circle"; radius: number; } & { kind: "circle"; } | ||
| > : ^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^ | ||
| >setValue : (newValue: Circle) => void | ||
| > : ^ ^^ ^^^^^ | ||
| >arg : [{ kind: "circle"; radius: number; } & { kind: "circle"; }, (newValue: Circle) => void] | ||
| > : ^^^^^^^^^ ^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^ ^^ ^^^^^ ^ | ||
| } | ||
| } | ||
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| function f1<T extends { a: "foo" } & { a: "bar" }>(x: T) { | ||
| >f1 : <T extends { a: "foo"; } & { a: "bar"; }>(x: T) => void | ||
| > : ^ ^^^^^^^^^ ^^ ^^ ^^^^^^^^^ | ||
| >a : "foo" | ||
| > : ^^^^^ | ||
| >a : "bar" | ||
| > : ^^^^^ | ||
| >x : T | ||
| > : ^ | ||
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| let [y] = x; // error | ||
| >y : never | ||
| > : ^^^^^ | ||
| >x : T | ||
| > : ^ | ||
| } | ||
|
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36 changes: 36 additions & 0 deletions
36
tests/baselines/reference/iterableWithNeverAsUnionMember(target=esnext).errors.txt
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,36 @@ | ||
| iterableWithNeverAsUnionMember.ts(2,7): error TS2488: Type 'never' must have a '[Symbol.iterator]()' method that returns an iterator. | ||
| iterableWithNeverAsUnionMember.ts(25,7): error TS2488: Type 'T' must have a '[Symbol.iterator]()' method that returns an iterator. | ||
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| ==== iterableWithNeverAsUnionMember.ts (2 errors) ==== | ||
| declare const o1: { a: "foo" } & { a: "bar" }; | ||
| const [el1] = o1; // error | ||
| ~~~~~ | ||
| !!! error TS2488: Type 'never' must have a '[Symbol.iterator]()' method that returns an iterator. | ||
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| // https://github.com/microsoft/TypeScript/issues/62462 | ||
| declare var x: number[] | ({ t: "a" } & { t: "b" }); | ||
| let [el2] = x; // ok | ||
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| for (const elem of x) { // ok | ||
| elem.toFixed(); | ||
| } | ||
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| type Shape = | ||
| | { kind: "circle"; radius: number } | ||
| | { kind: "rectangle"; width: number; height: number }; | ||
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| type Circle = Shape & { kind: "circle" }; | ||
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| function doStuffWithCircle(arg: Circle | [Circle, (newValue: Circle) => void]) { | ||
| if (Array.isArray(arg)) { | ||
| let [value, setValue] = arg; // ok | ||
| } | ||
| } | ||
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| function f1<T extends { a: "foo" } & { a: "bar" }>(x: T) { | ||
| let [y] = x; // error | ||
| ~~~ | ||
| !!! error TS2488: Type 'T' must have a '[Symbol.iterator]()' method that returns an iterator. | ||
| } | ||
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83 changes: 83 additions & 0 deletions
83
tests/baselines/reference/iterableWithNeverAsUnionMember(target=esnext).symbols
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,83 @@ | ||
| //// [tests/cases/compiler/iterableWithNeverAsUnionMember.ts] //// | ||
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| === iterableWithNeverAsUnionMember.ts === | ||
| declare const o1: { a: "foo" } & { a: "bar" }; | ||
| >o1 : Symbol(o1, Decl(iterableWithNeverAsUnionMember.ts, 0, 13)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 0, 19)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 0, 34)) | ||
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| const [el1] = o1; // error | ||
| >el1 : Symbol(el1, Decl(iterableWithNeverAsUnionMember.ts, 1, 7)) | ||
| >o1 : Symbol(o1, Decl(iterableWithNeverAsUnionMember.ts, 0, 13)) | ||
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| // https://github.com/microsoft/TypeScript/issues/62462 | ||
| declare var x: number[] | ({ t: "a" } & { t: "b" }); | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 4, 11)) | ||
| >t : Symbol(t, Decl(iterableWithNeverAsUnionMember.ts, 4, 28)) | ||
| >t : Symbol(t, Decl(iterableWithNeverAsUnionMember.ts, 4, 41)) | ||
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| let [el2] = x; // ok | ||
| >el2 : Symbol(el2, Decl(iterableWithNeverAsUnionMember.ts, 5, 5)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 4, 11)) | ||
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| for (const elem of x) { // ok | ||
| >elem : Symbol(elem, Decl(iterableWithNeverAsUnionMember.ts, 7, 10)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 4, 11)) | ||
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| elem.toFixed(); | ||
| >elem.toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --)) | ||
| >elem : Symbol(elem, Decl(iterableWithNeverAsUnionMember.ts, 7, 10)) | ||
| >toFixed : Symbol(Number.toFixed, Decl(lib.es5.d.ts, --, --)) | ||
| } | ||
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| type Shape = | ||
| >Shape : Symbol(Shape, Decl(iterableWithNeverAsUnionMember.ts, 9, 1)) | ||
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| | { kind: "circle"; radius: number } | ||
| >kind : Symbol(kind, Decl(iterableWithNeverAsUnionMember.ts, 12, 5)) | ||
| >radius : Symbol(radius, Decl(iterableWithNeverAsUnionMember.ts, 12, 21)) | ||
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| | { kind: "rectangle"; width: number; height: number }; | ||
| >kind : Symbol(kind, Decl(iterableWithNeverAsUnionMember.ts, 13, 5)) | ||
| >width : Symbol(width, Decl(iterableWithNeverAsUnionMember.ts, 13, 24)) | ||
| >height : Symbol(height, Decl(iterableWithNeverAsUnionMember.ts, 13, 39)) | ||
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| type Circle = Shape & { kind: "circle" }; | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
| >Shape : Symbol(Shape, Decl(iterableWithNeverAsUnionMember.ts, 9, 1)) | ||
| >kind : Symbol(kind, Decl(iterableWithNeverAsUnionMember.ts, 15, 23)) | ||
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| function doStuffWithCircle(arg: Circle | [Circle, (newValue: Circle) => void]) { | ||
| >doStuffWithCircle : Symbol(doStuffWithCircle, Decl(iterableWithNeverAsUnionMember.ts, 15, 41)) | ||
| >arg : Symbol(arg, Decl(iterableWithNeverAsUnionMember.ts, 17, 27)) | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
| >newValue : Symbol(newValue, Decl(iterableWithNeverAsUnionMember.ts, 17, 51)) | ||
| >Circle : Symbol(Circle, Decl(iterableWithNeverAsUnionMember.ts, 13, 57)) | ||
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| if (Array.isArray(arg)) { | ||
| >Array.isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --)) | ||
| >Array : Symbol(Array, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --) ... and 4 more) | ||
| >isArray : Symbol(ArrayConstructor.isArray, Decl(lib.es5.d.ts, --, --)) | ||
| >arg : Symbol(arg, Decl(iterableWithNeverAsUnionMember.ts, 17, 27)) | ||
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| let [value, setValue] = arg; // ok | ||
| >value : Symbol(value, Decl(iterableWithNeverAsUnionMember.ts, 19, 9)) | ||
| >setValue : Symbol(setValue, Decl(iterableWithNeverAsUnionMember.ts, 19, 15)) | ||
| >arg : Symbol(arg, Decl(iterableWithNeverAsUnionMember.ts, 17, 27)) | ||
| } | ||
| } | ||
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| function f1<T extends { a: "foo" } & { a: "bar" }>(x: T) { | ||
| >f1 : Symbol(f1, Decl(iterableWithNeverAsUnionMember.ts, 21, 1)) | ||
| >T : Symbol(T, Decl(iterableWithNeverAsUnionMember.ts, 23, 12)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 23, 23)) | ||
| >a : Symbol(a, Decl(iterableWithNeverAsUnionMember.ts, 23, 38)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 23, 51)) | ||
| >T : Symbol(T, Decl(iterableWithNeverAsUnionMember.ts, 23, 12)) | ||
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| let [y] = x; // error | ||
| >y : Symbol(y, Decl(iterableWithNeverAsUnionMember.ts, 24, 7)) | ||
| >x : Symbol(x, Decl(iterableWithNeverAsUnionMember.ts, 23, 51)) | ||
| } | ||
|
|
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q: what if all union members reduce to never? wouldn't this break a case like this?
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You're right, in that case TS allows the destructuring and types
el2asnever.I went with an alternative solution: reduce the whole iterable-like type instead of the union members:
93fb716(#62661).Added this case to the test as well