diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts index 778e31b9c5ba7..a81cf64fa1536 100644 --- a/src/compiler/checker.ts +++ b/src/compiler/checker.ts @@ -11252,13 +11252,7 @@ namespace ts { } function checkSpreadExpression(node: SpreadElement, contextualMapper?: TypeMapper): Type { - // It is usually not safe to call checkExpressionCached if we can be contextually typing. - // You can tell that we are contextually typing because of the contextualMapper parameter. - // While it is true that a spread element can have a contextual type, it does not do anything - // with this type. It is neither affected by it, nor does it propagate it to its operand. - // So the fact that contextualMapper is passed is not important, because the operand of a spread - // element is not contextually typed. - const arrayOrIterableType = checkExpressionCached(node.expression, contextualMapper); + const arrayOrIterableType = checkExpression(node.expression, contextualMapper); return checkIteratedTypeOrElementType(arrayOrIterableType, node.expression, /*allowStringInput*/ false); } diff --git a/tests/baselines/reference/selfReferencingSpreadInLoop.errors.txt b/tests/baselines/reference/selfReferencingSpreadInLoop.errors.txt new file mode 100644 index 0000000000000..599c9fbedb079 --- /dev/null +++ b/tests/baselines/reference/selfReferencingSpreadInLoop.errors.txt @@ -0,0 +1,14 @@ +tests/cases/compiler/selfReferencingSpreadInLoop.ts(1,5): error TS7034: Variable 'additional' implicitly has type 'any[]' in some locations where its type cannot be determined. +tests/cases/compiler/selfReferencingSpreadInLoop.ts(3,22): error TS7005: Variable 'additional' implicitly has an 'any[]' type. + + +==== tests/cases/compiler/selfReferencingSpreadInLoop.ts (2 errors) ==== + let additional = []; + ~~~~~~~~~~ +!!! error TS7034: Variable 'additional' implicitly has type 'any[]' in some locations where its type cannot be determined. + for (const subcomponent of [1, 2, 3]) { + additional = [...additional, subcomponent]; + ~~~~~~~~~~ +!!! error TS7005: Variable 'additional' implicitly has an 'any[]' type. + } + \ No newline at end of file diff --git a/tests/baselines/reference/selfReferencingSpreadInLoop.js b/tests/baselines/reference/selfReferencingSpreadInLoop.js new file mode 100644 index 0000000000000..1b8d5ace4f3f5 --- /dev/null +++ b/tests/baselines/reference/selfReferencingSpreadInLoop.js @@ -0,0 +1,13 @@ +//// [selfReferencingSpreadInLoop.ts] +let additional = []; +for (const subcomponent of [1, 2, 3]) { + additional = [...additional, subcomponent]; +} + + +//// [selfReferencingSpreadInLoop.js] +var additional = []; +for (var _i = 0, _a = [1, 2, 3]; _i < _a.length; _i++) { + var subcomponent = _a[_i]; + additional = additional.concat([subcomponent]); +} diff --git a/tests/cases/compiler/selfReferencingSpreadInLoop.ts b/tests/cases/compiler/selfReferencingSpreadInLoop.ts new file mode 100644 index 0000000000000..0900e6cad636b --- /dev/null +++ b/tests/cases/compiler/selfReferencingSpreadInLoop.ts @@ -0,0 +1,5 @@ +// @noImplicitAny: true +let additional = []; +for (const subcomponent of [1, 2, 3]) { + additional = [...additional, subcomponent]; +}