File size: 1,735 Bytes
c212805 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 | import { isStorageError } from '../lib/common/errors'
import { DownloadResult } from '../lib/types'
export default class StreamDownloadBuilder implements Promise<DownloadResult<ReadableStream>> {
readonly [Symbol.toStringTag]: string = 'StreamDownloadBuilder'
private promise: Promise<DownloadResult<ReadableStream>> | null = null
constructor(
private downloadFn: () => Promise<Response>,
private shouldThrowOnError: boolean
) {}
then<TResult1 = DownloadResult<ReadableStream>, TResult2 = never>(
onfulfilled?:
| ((value: DownloadResult<ReadableStream>) => TResult1 | PromiseLike<TResult1>)
| null,
onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | null
): Promise<TResult1 | TResult2> {
return this.getPromise().then(onfulfilled, onrejected)
}
catch<TResult = never>(
onrejected?: ((reason: any) => TResult | PromiseLike<TResult>) | null
): Promise<DownloadResult<ReadableStream> | TResult> {
return this.getPromise().catch(onrejected)
}
finally(onfinally?: (() => void) | null): Promise<DownloadResult<ReadableStream>> {
return this.getPromise().finally(onfinally)
}
private getPromise(): Promise<DownloadResult<ReadableStream>> {
if (!this.promise) {
this.promise = this.execute()
}
return this.promise
}
private async execute(): Promise<DownloadResult<ReadableStream>> {
try {
const result = await this.downloadFn()
return {
data: result.body as ReadableStream,
error: null,
}
} catch (error) {
if (this.shouldThrowOnError) {
throw error
}
if (isStorageError(error)) {
return { data: null, error }
}
throw error
}
}
}
|