mirror of
https://github.com/swc-project/swc.git
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107 lines
1.5 KiB
TypeScript
107 lines
1.5 KiB
TypeScript
// @strictNullChecks: true
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type A = {
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type: 'A';
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name: string;
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}
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type B = {
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type: 'B';
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}
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function funcTwo(arg: A | B | undefined) {
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if (arg?.type === 'B') {
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arg; // `B`
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return;
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}
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arg;
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arg?.name;
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}
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function funcThree(arg: A | B | null) {
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if (arg?.type === 'B') {
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arg; // `B`
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return;
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}
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arg;
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arg?.name;
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}
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type U = { kind: undefined, u: 'u' }
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type N = { kind: null, n: 'n' }
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type X = { kind: 'X', x: 'x' }
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function f1(x: X | U | undefined) {
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if (x?.kind === undefined) {
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x; // U | undefined
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}
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else {
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x; // X
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}
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}
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function f2(x: X | N | undefined) {
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if (x?.kind === undefined) {
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x; // undefined
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}
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else {
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x; // X | N
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}
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}
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function f3(x: X | U | null) {
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if (x?.kind === undefined) {
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x; // U | null
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}
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else {
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x; // X
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}
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}
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function f4(x: X | N | null) {
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if (x?.kind === undefined) {
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x; // null
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}
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else {
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x; // X | N
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}
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}
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function f5(x: X | U | undefined) {
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if (x?.kind === null) {
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x; // never
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}
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else {
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x; // X | U | undefined
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}
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}
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function f6(x: X | N | undefined) {
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if (x?.kind === null) {
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x; // N
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}
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else {
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x; // X | undefined
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}
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}
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function f7(x: X | U | null) {
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if (x?.kind === null) {
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x; // never
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}
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else {
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x; // X | U | null
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}
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}
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function f8(x: X | N | null) {
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if (x?.kind === null) {
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x; // N
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}
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else {
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x; // X | null
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}
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}
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