Proper treatment of splicing tuples in array literals #36861
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elibarzilay
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Looks basically right and the baselines improve. I agree with @weswigham that isTupleLikeType is preferable.
Fixes microsoft#32465. After this was done, I continued to extend the implementation to handle TupleLike types but it'ss broken since JS doesn't allow splicing TupleLike values into array literals so pulled that out, and instead keeping it for reference below. (It Includes tests, which are broken too.) modified src/compiler/checker.ts @@ -22268,6 +22268,21 @@ namespace ts { else hasNonEndingSpreadElement = true; } } + else if (spreadType && isTupleLikeType(spreadType)) { + let i = 0, tupleEltType: Type | undefined; + while (tupleEltType = getTypeOfPropertyOfType(spreadType, "" + i as __String)) { + elementTypes.push(tupleEltType); + i++; + } + const stringIndexInfo = getIndexInfoOfType(spreadType, IndexKind.String); + const numberIndexInfo = getIndexInfoOfType(spreadType, IndexKind.Number); + if (stringIndexInfo || numberIndexInfo) { + if (stringIndexInfo) elementTypes.push(stringIndexInfo.type); + if (numberIndexInfo) elementTypes.push(numberIndexInfo.type); + if (i === elementCount - 1) hasEndingSpreadElement = true; + else hasNonEndingSpreadElement = true; + } + } else { if (inDestructuringPattern && spreadType) { // Given the following situation: new file tests/cases/compiler/spliceTupleLikesWIntegers.ts @@ -0,0 +1,23 @@ +declare const sb: { [0]: string, [1]: boolean }; + +let k1: [number, string, boolean]; +k1 = [1, ...sb]; + +let k2: [number, string, boolean, number]; +k2 = [1, ...sb, 1]; + +// declare const sb_: [string, ...boolean[]]; + +// let k3: [number, string, ...boolean[]]; +// k3 = [1, ...sb_]; + +// declare const sbb_: [string, boolean, ...boolean[]]; + +// let k4: [number, string, ...boolean[]]; +// k4 = [1, ...sbb_]; + +// let k5: [number, string, boolean, ...boolean[]]; +// k5 = [1, ...sbb_]; + +// let k6: [number, string, boolean, boolean, ...boolean[]]; +// k6 = [1, ...sbb_]; new file tests/cases/compiler/spliceTupleLikesWStrings.ts @@ -0,0 +1,23 @@ +declare const sb: { 0: string, 1: boolean }; + +let k1: [number, string, boolean]; +k1 = [1, ...sb]; + +let k2: [number, string, boolean, number]; +k2 = [1, ...sb, 1]; + +declare const sb_: { 0: string, [s: string]: (boolean|string) }; + +let k3: [number, string, ...(boolean|string)[]]; +k3 = [1, ...sb_]; + +declare const sbb_: { 0: string, 1: boolean, [s: string]: (boolean|string) }; + +let k4: [number, string, boolean, ...(boolean|string)[]]; +k4 = [1, ...sbb_]; + +// let k5: [number, string, boolean, ...(boolean|string)[]]; +// k5 = [1, ...sbb_]; + +// let k6: [number, string, boolean, boolean, ...(boolean|string)[]]; +// k6 = [1, ...sbb_];
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Thank you for the fix. Would it solve this issue as well? const date: Date = new Date();
const num = 42;
// OK
const [a, b]: [Date, number] = [date, num];
const args = [date, num];
// Type '(number | Date)[]' is missing the following properties from type '[Date, number]': 0, 1(2739)
const [c, d]: [Date, number] = args; |
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No, that's caused by the lack of contextual typing in |
i dont know what happend in this case , is this the same problem? |
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@GRJser, no -- this was only about splicing into array literals. There is this PR that fixes some spreads in calls and might be relevant for your example. |
Fixes #32465.