Skip to content

Extend isTupleLikeType to also check if .length is a number literal type #52617

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 4 additions & 1 deletion src/compiler/checker.ts
Original file line number Diff line number Diff line change
Expand Up @@ -23272,7 +23272,10 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
}

function isTupleLikeType(type: Type): boolean {
return isTupleType(type) || !!getPropertyOfType(type, "0" as __String);
let lengthType;
return isTupleType(type) ||
!!getPropertyOfType(type, "0" as __String) ||
isArrayLikeType(type) && !!(lengthType = getTypeOfPropertyOfType(type, "length" as __String)) && everyType(lengthType, t => !!(t.flags & TypeFlags.NumberLiteral));
}

function isArrayOrTupleLikeType(type: Type): boolean {
Expand Down
13 changes: 12 additions & 1 deletion tests/baselines/reference/contextualTypeWithTuple.errors.txt
Original file line number Diff line number Diff line change
Expand Up @@ -68,4 +68,15 @@ contextualTypeWithTuple.ts(25,1): error TS2322: Type '[number, string | number]'
!!! error TS2322: Type '[number, string | number]' is not assignable to type '[number, string]'.
!!! error TS2322: Type at position 1 in source is not compatible with type at position 1 in target.
!!! error TS2322: Type 'string | number' is not assignable to type 'string'.
!!! error TS2322: Type 'number' is not assignable to type 'string'.
!!! error TS2322: Type 'number' is not assignable to type 'string'.

// repro from #29311
type test1 = [...number[]]
type fixed1 = test1 & { length: 2 }
let var1: fixed1 = [0, 0]

// #52551
type EmptyTuple = []
interface MyEmptyTuple extends EmptyTuple { extraInfo?: any; }
const withExtra: MyEmptyTuple = []

15 changes: 14 additions & 1 deletion tests/baselines/reference/contextualTypeWithTuple.js
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,18 @@ var strStrTuple: [string, string] = ["foo", "bar", 5];
unionTuple = unionTuple1;
unionTuple = unionTuple2;
unionTuple2 = unionTuple;
numStrTuple = unionTuple3;
numStrTuple = unionTuple3;

// repro from #29311
type test1 = [...number[]]
type fixed1 = test1 & { length: 2 }
let var1: fixed1 = [0, 0]

// #52551
type EmptyTuple = []
interface MyEmptyTuple extends EmptyTuple { extraInfo?: any; }
const withExtra: MyEmptyTuple = []


//// [contextualTypeWithTuple.js]
// no error
Expand Down Expand Up @@ -58,3 +69,5 @@ unionTuple = unionTuple1;
unionTuple = unionTuple2;
unionTuple2 = unionTuple;
numStrTuple = unionTuple3;
var var1 = [0, 0];
var withExtra = [];
26 changes: 26 additions & 0 deletions tests/baselines/reference/contextualTypeWithTuple.symbols
Original file line number Diff line number Diff line change
Expand Up @@ -82,3 +82,29 @@ numStrTuple = unionTuple3;
>numStrTuple : Symbol(numStrTuple, Decl(contextualTypeWithTuple.ts, 1, 3))
>unionTuple3 : Symbol(unionTuple3, Decl(contextualTypeWithTuple.ts, 11, 3))

// repro from #29311
type test1 = [...number[]]
>test1 : Symbol(test1, Decl(contextualTypeWithTuple.ts, 24, 26))

type fixed1 = test1 & { length: 2 }
>fixed1 : Symbol(fixed1, Decl(contextualTypeWithTuple.ts, 27, 26))
>test1 : Symbol(test1, Decl(contextualTypeWithTuple.ts, 24, 26))
>length : Symbol(length, Decl(contextualTypeWithTuple.ts, 28, 23))

let var1: fixed1 = [0, 0]
>var1 : Symbol(var1, Decl(contextualTypeWithTuple.ts, 29, 3))
>fixed1 : Symbol(fixed1, Decl(contextualTypeWithTuple.ts, 27, 26))

// #52551
type EmptyTuple = []
>EmptyTuple : Symbol(EmptyTuple, Decl(contextualTypeWithTuple.ts, 29, 25))

interface MyEmptyTuple extends EmptyTuple { extraInfo?: any; }
>MyEmptyTuple : Symbol(MyEmptyTuple, Decl(contextualTypeWithTuple.ts, 32, 20))
>EmptyTuple : Symbol(EmptyTuple, Decl(contextualTypeWithTuple.ts, 29, 25))
>extraInfo : Symbol(MyEmptyTuple.extraInfo, Decl(contextualTypeWithTuple.ts, 33, 43))

const withExtra: MyEmptyTuple = []
>withExtra : Symbol(withExtra, Decl(contextualTypeWithTuple.ts, 34, 5))
>MyEmptyTuple : Symbol(MyEmptyTuple, Decl(contextualTypeWithTuple.ts, 32, 20))

25 changes: 25 additions & 0 deletions tests/baselines/reference/contextualTypeWithTuple.types
Original file line number Diff line number Diff line change
Expand Up @@ -128,3 +128,28 @@ numStrTuple = unionTuple3;
>numStrTuple : [number, string]
>unionTuple3 : [number, string | number]

// repro from #29311
type test1 = [...number[]]
>test1 : number[]

type fixed1 = test1 & { length: 2 }
>fixed1 : test1 & { length: 2; }
>length : 2

let var1: fixed1 = [0, 0]
>var1 : fixed1
>[0, 0] : [number, number]
>0 : 0
>0 : 0

// #52551
type EmptyTuple = []
>EmptyTuple : []

interface MyEmptyTuple extends EmptyTuple { extraInfo?: any; }
>extraInfo : any

const withExtra: MyEmptyTuple = []
>withExtra : MyEmptyTuple
>[] : []

12 changes: 11 additions & 1 deletion tests/cases/conformance/types/tuple/contextualTypeWithTuple.ts
Original file line number Diff line number Diff line change
Expand Up @@ -22,4 +22,14 @@ var strStrTuple: [string, string] = ["foo", "bar", 5];
unionTuple = unionTuple1;
unionTuple = unionTuple2;
unionTuple2 = unionTuple;
numStrTuple = unionTuple3;
numStrTuple = unionTuple3;

// repro from #29311
type test1 = [...number[]]
type fixed1 = test1 & { length: 2 }
let var1: fixed1 = [0, 0]

// #52551
type EmptyTuple = []
interface MyEmptyTuple extends EmptyTuple { extraInfo?: any; }
const withExtra: MyEmptyTuple = []