66 lines
1.3 KiB
TypeScript
66 lines
1.3 KiB
TypeScript
// @strictNullChecks: true
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function f1(s: string) {
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if (s === "foo") {
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s; // "foo"
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}
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if (s === "foo" || s === "bar") {
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s; // "foo" | "bar"
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}
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}
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function f2(s: string) {
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switch (s) {
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case "foo":
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case "bar":
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s; // "foo" | "bar"
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case "baz":
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s; // "foo" | "bar" | "baz"
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break;
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default:
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s; // string
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}
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}
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function f3(s: string) {
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return s === "foo" || s === "bar" ? s : undefined; // "foo" | "bar" | undefined
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}
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function f4(x: number) {
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if (x === 1 || x === 2) {
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return x; // 1 | 2
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}
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throw new Error();
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}
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function f5(x: number, y: 1 | 2) {
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if (x === 0 || x === y) {
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x; // 0 | 1 | 2
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}
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}
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function f6(x: number, y: 1 | 2) {
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if (y === x || 0 === x) {
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x; // 0 | 1 | 2
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}
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}
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function f7(x: number | "foo" | "bar", y: 1 | 2 | string) {
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if (x === y) {
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x; // "foo" | "bar" | 1 | 2
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}
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}
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function f8(x: number | "foo" | "bar") {
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switch (x) {
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case 1:
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case 2:
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x; // 1 | 2
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break;
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case "foo":
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x; // "foo"
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break;
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default:
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x; // number | "bar"
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}
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} |