93 lines
2.1 KiB
TypeScript
93 lines
2.1 KiB
TypeScript
//// [weakType.ts]
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interface Settings {
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timeout?: number;
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onError?(): void;
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}
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function getDefaultSettings() {
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return { timeout: 1000 };
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}
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interface CtorOnly {
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new(s: string): { timeout: 1000 }
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}
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function doSomething(settings: Settings) { /* ... */ }
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// forgot to call `getDefaultSettings`
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doSomething(getDefaultSettings);
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doSomething(() => ({ timeout: 1000 }));
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doSomething(null as CtorOnly);
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doSomething(12);
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doSomething('completely wrong');
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doSomething(false);
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// this is an oddly popular way of defining settings
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// this example is from services/textChanges.ts
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type ConfigurableStart = { useStart?: boolean }
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type ConfigurableEnd = { useEnd?: boolean }
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type ConfigurableStartEnd = ConfigurableStart & ConfigurableEnd
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interface InsertOptions {
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prefix?: string
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suffix?: string
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}
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type ChangeOptions = ConfigurableStartEnd & InsertOptions;
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function del(options: ConfigurableStartEnd = {},
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error: { error?: number } = {}) {
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let changes: ChangeOptions[];
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changes.push(options);
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changes.push(error);
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}
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class K {
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constructor(s: string) { }
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}
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// Ctor isn't a weak type because it has a construct signature
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interface Ctor {
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new (s: string): K
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n?: number
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}
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let ctor: Ctor = K
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type Spoiler = { nope?: string }
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type Weak = {
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a?: number
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properties?: {
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b?: number
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}
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}
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declare let unknown: {
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properties: {
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wrong: string
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}
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}
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let weak: Weak & Spoiler = unknown
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//// [weakType.js]
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function getDefaultSettings() {
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return { timeout: 1000 };
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}
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function doSomething(settings) { }
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// forgot to call `getDefaultSettings`
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doSomething(getDefaultSettings);
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doSomething(function () { return ({ timeout: 1000 }); });
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doSomething(null);
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doSomething(12);
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doSomething('completely wrong');
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doSomething(false);
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function del(options, error) {
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if (options === void 0) { options = {}; }
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if (error === void 0) { error = {}; }
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var changes;
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changes.push(options);
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changes.push(error);
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}
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var K = /** @class */ (function () {
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function K(s) {
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}
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return K;
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}());
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var ctor = K;
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var weak = unknown;
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