diff --git a/tests/cases/conformance/types/union/discriminatedUnionTypes2.ts b/tests/cases/conformance/types/union/discriminatedUnionTypes2.ts new file mode 100644 index 0000000000..789bc263c7 --- /dev/null +++ b/tests/cases/conformance/types/union/discriminatedUnionTypes2.ts @@ -0,0 +1,74 @@ +// @strict: true + +function f10(x : { kind: false, a: string } | { kind: true, b: string } | { kind: string, c: string }) { + if (x.kind === false) { + x.a; + } + else if (x.kind === true) { + x.b; + } + else { + x.c; + } +} + +function f11(x : { kind: false, a: string } | { kind: true, b: string } | { kind: string, c: string }) { + switch (x.kind) { + case false: + x.a; + break; + case true: + x.b; + break; + default: + x.c; + } +} + +function f13(x: { a: null; b: string } | { a: string, c: number }) { + x = { a: null, b: "foo", c: 4}; // Error +} + +function f14(x: { a: 0; b: string } | { a: T, c: number }) { + if (x.a === 0) { + x.b; // Error + } +} + +type Result = { error?: undefined, value: T } | { error: Error }; + +function f15(x: Result) { + if (!x.error) { + x.value; + } + else { + x.error.message; + } +} + +f15({ value: 10 }); +f15({ error: new Error("boom") }); + +// Repro from #24193 + +interface WithError { + error: Error + data: null +} + +interface WithoutError { + error: null + data: Data +} + +type DataCarrier = WithError | WithoutError + +function f20(carrier: DataCarrier) { + if (carrier.error === null) { + const error: null = carrier.error + const data: Data = carrier.data + } else { + const error: Error = carrier.error + const data: null = carrier.data + } +}