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Deferred values with pulumi-kubernetes
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| import * as pulumi from "@pulumi/pulumi"; | |
| import assert from "node:assert/strict"; | |
| // Short solution: | |
| type DeferredOutput<T> = pulumi.Output<T> & { | |
| resolve: (value: pulumi.Input<T>) => void, | |
| reject: (reason?: any) => void; | |
| } | |
| export function deferredOutput<T>() { | |
| let _resolve; | |
| let _reject; | |
| let prom = new Promise<pulumi.Input<T>>((resolve, reject) => { | |
| _resolve = resolve; | |
| _reject = reject; | |
| }); | |
| assert(_resolve !== undefined); | |
| assert(_reject !== undefined); | |
| let output = pulumi.output(prom) as DeferredOutput<pulumi.Unwrap<T>>; | |
| output.resolve = _resolve; | |
| output.reject = _reject; | |
| return output; | |
| } | |
| // Full deferred promise: | |
| /** | |
| * Deferred promise | |
| * Allows passing around Promises that do not have an executor. | |
| * This is FREAKING DANGEROUS | |
| * because it creates promises that, by default, never resolve. | |
| */ | |
| export class Deferred<T> extends Promise<T> { | |
| resolve: (value: T | PromiseLike<T>) => void; | |
| reject: (reason?: any) => void; | |
| constructor () { | |
| let _resolve; | |
| let _reject; | |
| super((resolve, reject) => { | |
| _resolve = resolve; | |
| _reject = reject; | |
| }); | |
| assert(_resolve !== undefined); | |
| assert(_reject !== undefined); | |
| this.resolve = _resolve; | |
| this.reject = _reject; | |
| } | |
| static get [Symbol.species] () { | |
| return Promise; | |
| } | |
| get [Symbol.toStringTag] () { | |
| return "DeferredPromise"; | |
| } | |
| } | |
| type MagicDeferred<T> = T extends pulumi.Input<infer U> | |
| ? U extends object ? _MagicDeferredObject<T> : T // eslint-disable-line no-use-before-define | |
| : T extends object ? _MagicDeferredObject<T> : Promise<T> // eslint-disable-line no-use-before-define | |
| type _MagicDeferredObject<T> = { | |
| [P in keyof T] : MagicDeferred<T[P]> | |
| } | |
| /** | |
| * Magic wrapper to quickly make deferred versions of objects. | |
| */ | |
| export function deferred<T> (promise?: Promise<T>): Deferred<T> & MagicDeferred<T> { | |
| if (promise === undefined) { | |
| promise = new Deferred<T>(); | |
| } | |
| // Use Proxy to catch property accesses and defer them | |
| const obj = new Proxy(promise, { | |
| get: (target, property) => { | |
| // Don't defer access to `Promise`'s properties (eg `then`) | |
| if (property in target) { | |
| let value = (target as any)[property]; | |
| if (typeof value === "function") { | |
| value = value.bind(target); | |
| } | |
| return value; | |
| } | |
| // return deferred property access | |
| return deferred(target.then((value: any) => value[property])); | |
| } | |
| }); | |
| return obj as any; | |
| } | |
| // --- | |
| function test(toto: pulumi.Input<string>) { | |
| pulumi.output(toto).apply(resolved => console.log(resolved)); | |
| } | |
| const ghost = deferred<{a: {b: {z: string}}}>(); | |
| test(ghost.a.b.z); | |
| ghost.resolve({a: {b: {z: "Hello World !"}}}) |
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