46 lines
1.5 KiB
JavaScript
46 lines
1.5 KiB
JavaScript
/* @flow */
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function testKeysOfObject(str: string, lit: 'hi') {
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(str: $Keys<Object>); // Any string should be fine
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if (str) {
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(str: $Keys<Object>); // No error, truthy string should be fine
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}
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('hi': $Keys<Object>); // String literal should be fine
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(123: $Keys<Object>); // Error: number -> keys of Object
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}
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type StrDict = {[key: string]: mixed};
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function testKeysOfStrDict(str: string, lit: 'hi') {
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(str: $Keys<StrDict>); // Any string should be fine
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if (str) {
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(str: $Keys<StrDict>); // No error, truthy string should be fine
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}
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('hi': $Keys<StrDict>); // String literal should be fine
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(123: $Keys<StrDict>); // Error: number -> keys of StrDict
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}
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type StrLitDict = {[key: 'hi']: mixed};
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function testKeysOfStrLitDict(str: string, lit: 'hi') {
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(str: $Keys<StrLitDict>); // Error: Not all strings are allowed
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if (str) {
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(str: $Keys<StrLitDict>); // Error: Not all truthy strings are allowed
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}
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('hi': $Keys<StrLitDict>); // The right string literal is allowed
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('bye': $Keys<StrLitDict>); // Error: The wrong string literal is not allowed
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(123: $Keys<StrLitDict>); // Error: number -> keys of StrLitDict
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}
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type ObjLit = {hi: mixed};
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function testKeysOfOtherObj(str: string, lit: 'hi') {
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(str: $Keys<ObjLit>); // Error: string -> keys of ObjLit
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if (str) {
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(str: $Keys<ObjLit>); // Error: truthy string -> keys of ObjLit
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}
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('hi': $Keys<ObjLit>); // String literal should be fine
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(123: $Keys<ObjLit>); // Error: number -> keys of ObjLit
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}
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