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2 | 2 |
|
3 | 3 | export class CancelError extends Error { |
4 | 4 |
|
5 | | - constructor(message: string) { |
6 | | - super(message); |
7 | | - this.name = 'CancelError'; |
8 | | - } |
9 | | - |
10 | | - public get isCancelled(): boolean { |
11 | | - return true; |
12 | | - } |
| 5 | + constructor(message: string) { |
| 6 | + super(message); |
| 7 | + this.name = 'CancelError'; |
| 8 | + } |
| 9 | + |
| 10 | + public get isCancelled(): boolean { |
| 11 | + return true; |
| 12 | + } |
13 | 13 | } |
14 | 14 |
|
15 | 15 | export interface OnCancel { |
16 | | - readonly isResolved: boolean; |
17 | | - readonly isRejected: boolean; |
18 | | - readonly isCancelled: boolean; |
| 16 | + readonly isResolved: boolean; |
| 17 | + readonly isRejected: boolean; |
| 18 | + readonly isCancelled: boolean; |
19 | 19 |
|
20 | | - (cancelHandler: () => void): void; |
| 20 | + (cancelHandler: () => void): void; |
21 | 21 | } |
22 | 22 |
|
23 | 23 | export class CancelablePromise<T> implements Promise<T> { |
24 | | - readonly [Symbol.toStringTag]: string; |
25 | | - |
26 | | - #isResolved: boolean; |
27 | | - #isRejected: boolean; |
28 | | - #isCancelled: boolean; |
29 | | - readonly #cancelHandlers: (() => void)[]; |
30 | | - readonly #promise: Promise<T>; |
31 | | - #resolve?: (value: T | PromiseLike<T>) => void; |
32 | | - #reject?: (reason?: any) => void; |
33 | | - |
34 | | - constructor( |
35 | | - executor: ( |
36 | | - resolve: (value: T | PromiseLike<T>) => void, |
37 | | - reject: (reason?: any) => void, |
38 | | - onCancel: OnCancel |
39 | | - ) => void |
40 | | - ) { |
41 | | - this.#isResolved = false; |
42 | | - this.#isRejected = false; |
43 | | - this.#isCancelled = false; |
44 | | - this.#cancelHandlers = []; |
45 | | - this.#promise = new Promise<T>((resolve, reject) => { |
46 | | - this.#resolve = resolve; |
47 | | - this.#reject = reject; |
48 | | - |
49 | | - const onResolve = (value: T | PromiseLike<T>): void => { |
50 | | - if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
51 | | - return; |
52 | | - } |
53 | | - this.#isResolved = true; |
54 | | - this.#resolve?.(value); |
55 | | - }; |
56 | | - |
57 | | - const onReject = (reason?: any): void => { |
58 | | - if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
59 | | - return; |
60 | | - } |
61 | | - this.#isRejected = true; |
62 | | - this.#reject?.(reason); |
63 | | - }; |
64 | | - |
65 | | - const onCancel = (cancelHandler: () => void): void => { |
66 | | - if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
67 | | - return; |
68 | | - } |
69 | | - this.#cancelHandlers.push(cancelHandler); |
70 | | - }; |
71 | | - |
72 | | - Object.defineProperty(onCancel, 'isResolved', { |
73 | | - get: (): boolean => this.#isResolved, |
74 | | - }); |
75 | | - |
76 | | - Object.defineProperty(onCancel, 'isRejected', { |
77 | | - get: (): boolean => this.#isRejected, |
78 | | - }); |
79 | | - |
80 | | - Object.defineProperty(onCancel, 'isCancelled', { |
81 | | - get: (): boolean => this.#isCancelled, |
82 | | - }); |
83 | | - |
84 | | - return executor(onResolve, onReject, onCancel as OnCancel); |
85 | | - }); |
86 | | - } |
87 | | - |
88 | | - public then<TResult1 = T, TResult2 = never>( |
89 | | - onFulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | null, |
90 | | - onRejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | null |
91 | | - ): Promise<TResult1 | TResult2> { |
92 | | - return this.#promise.then(onFulfilled, onRejected); |
93 | | - } |
94 | | - |
95 | | - public catch<TResult = never>( |
96 | | - onRejected?: ((reason: any) => TResult | PromiseLike<TResult>) | null |
97 | | - ): Promise<T | TResult> { |
98 | | - return this.#promise.catch(onRejected); |
99 | | - } |
100 | | - |
101 | | - public finally(onFinally?: (() => void) | null): Promise<T> { |
102 | | - return this.#promise.finally(onFinally); |
103 | | - } |
104 | | - |
105 | | - public cancel(): void { |
106 | | - if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
107 | | - return; |
108 | | - } |
109 | | - this.#isCancelled = true; |
110 | | - if (this.#cancelHandlers.length) { |
111 | | - try { |
112 | | - for (const cancelHandler of this.#cancelHandlers) { |
113 | | - cancelHandler(); |
114 | | - } |
115 | | - } catch (error) { |
116 | | - console.warn('Cancellation threw an error', error); |
117 | | - return; |
118 | | - } |
119 | | - } |
120 | | - this.#cancelHandlers.length = 0; |
121 | | - this.#reject?.(new CancelError('Request aborted')); |
122 | | - } |
123 | | - |
124 | | - public get isCancelled(): boolean { |
125 | | - return this.#isCancelled; |
126 | | - } |
| 24 | + readonly [Symbol.toStringTag]: string; |
| 25 | + |
| 26 | + #isResolved: boolean; |
| 27 | + #isRejected: boolean; |
| 28 | + #isCancelled: boolean; |
| 29 | + readonly #cancelHandlers: (() => void)[]; |
| 30 | + readonly #promise: Promise<T>; |
| 31 | + #resolve?: (value: T | PromiseLike<T>) => void; |
| 32 | + #reject?: (reason?: any) => void; |
| 33 | + |
| 34 | + constructor( |
| 35 | + executor: ( |
| 36 | + resolve: (value: T | PromiseLike<T>) => void, |
| 37 | + reject: (reason?: any) => void, |
| 38 | + onCancel: OnCancel |
| 39 | + ) => void |
| 40 | + ) { |
| 41 | + this.#isResolved = false; |
| 42 | + this.#isRejected = false; |
| 43 | + this.#isCancelled = false; |
| 44 | + this.#cancelHandlers = []; |
| 45 | + this.#promise = new Promise<T>((resolve, reject) => { |
| 46 | + this.#resolve = resolve; |
| 47 | + this.#reject = reject; |
| 48 | + |
| 49 | + const onResolve = (value: T | PromiseLike<T>): void => { |
| 50 | + if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
| 51 | + return; |
| 52 | + } |
| 53 | + this.#isResolved = true; |
| 54 | + this.#resolve?.(value); |
| 55 | + }; |
| 56 | + |
| 57 | + const onReject = (reason?: any): void => { |
| 58 | + if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
| 59 | + return; |
| 60 | + } |
| 61 | + this.#isRejected = true; |
| 62 | + this.#reject?.(reason); |
| 63 | + }; |
| 64 | + |
| 65 | + const onCancel = (cancelHandler: () => void): void => { |
| 66 | + if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
| 67 | + return; |
| 68 | + } |
| 69 | + this.#cancelHandlers.push(cancelHandler); |
| 70 | + }; |
| 71 | + |
| 72 | + Object.defineProperty(onCancel, 'isResolved', { |
| 73 | + get: (): boolean => this.#isResolved, |
| 74 | + }); |
| 75 | + |
| 76 | + Object.defineProperty(onCancel, 'isRejected', { |
| 77 | + get: (): boolean => this.#isRejected, |
| 78 | + }); |
| 79 | + |
| 80 | + Object.defineProperty(onCancel, 'isCancelled', { |
| 81 | + get: (): boolean => this.#isCancelled, |
| 82 | + }); |
| 83 | + |
| 84 | + return executor(onResolve, onReject, onCancel as OnCancel); |
| 85 | + }); |
| 86 | + } |
| 87 | + |
| 88 | + public then<TResult1 = T, TResult2 = never>( |
| 89 | + onFulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | null, |
| 90 | + onRejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | null |
| 91 | + ): Promise<TResult1 | TResult2> { |
| 92 | + return this.#promise.then(onFulfilled, onRejected); |
| 93 | + } |
| 94 | + |
| 95 | + public catch<TResult = never>( |
| 96 | + onRejected?: ((reason: any) => TResult | PromiseLike<TResult>) | null |
| 97 | + ): Promise<T | TResult> { |
| 98 | + return this.#promise.catch(onRejected); |
| 99 | + } |
| 100 | + |
| 101 | + public finally(onFinally?: (() => void) | null): Promise<T> { |
| 102 | + return this.#promise.finally(onFinally); |
| 103 | + } |
| 104 | + |
| 105 | + public cancel(): void { |
| 106 | + if (this.#isResolved || this.#isRejected || this.#isCancelled) { |
| 107 | + return; |
| 108 | + } |
| 109 | + this.#isCancelled = true; |
| 110 | + if (this.#cancelHandlers.length) { |
| 111 | + try { |
| 112 | + for (const cancelHandler of this.#cancelHandlers) { |
| 113 | + cancelHandler(); |
| 114 | + } |
| 115 | + } catch (error) { |
| 116 | + console.warn('Cancellation threw an error', error); |
| 117 | + return; |
| 118 | + } |
| 119 | + } |
| 120 | + this.#cancelHandlers.length = 0; |
| 121 | + this.#reject?.(new CancelError('Request aborted')); |
| 122 | + } |
| 123 | + |
| 124 | + public get isCancelled(): boolean { |
| 125 | + return this.#isCancelled; |
| 126 | + } |
127 | 127 | } |
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