Created
November 25, 2019 20:27
-
-
Save EndyKaufman/e5004e3b6584b46b0701cea9e649d978 to your computer and use it in GitHub Desktop.
callback-to-observable.ts
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import { Inject, Injectable } from '@nestjs/common'; | |
import { from, Observable } from 'rxjs'; | |
/** | |
* Костыль который превращает функции сервиса с калбак аргументом в обзервабл, | |
* для поддержки типизации в тестах | |
* | |
* @param service сервис созданный через загрузку прото файла (GRPC.loadPackageDefinition) | |
*/ | |
// tslint:disable-next-line: typedef | |
export function callbackToObservable<T = Observable<any>>(service: T, showErrors = true) { | |
return new Proxy( | |
{}, | |
{ | |
// tslint:disable-next-line: typedef | |
get(target, name) { | |
// tslint:disable-next-line: typedef | |
return function() { | |
if (arguments.length === 0) { | |
return from( | |
new Promise((resolve, reject) => { | |
try { | |
service[name](callback(name, reject, resolve, showErrors)); | |
} catch (error) { | |
callback(name, reject, resolve, showErrors)(error, null); | |
} | |
}) | |
); | |
} | |
if (arguments.length === 1) { | |
return from( | |
new Promise((resolve, reject) => { | |
try { | |
service[name](arguments[0], callback(name, reject, resolve, showErrors)); | |
} catch (error) { | |
callback(name, reject, resolve, showErrors)(error, null); | |
} | |
}) | |
); | |
} | |
if (arguments.length === 2) { | |
return from( | |
new Promise((resolve, reject) => { | |
try { | |
service[name](arguments[0], arguments[1], callback(name, reject, resolve, showErrors)); | |
} catch (error) { | |
callback(name, reject, resolve, showErrors)(error, null); | |
} | |
}) | |
); | |
} | |
if (arguments.length === 3) { | |
return from( | |
new Promise((resolve, reject) => { | |
try { | |
service[name](arguments[0], arguments[1], arguments[2], callback(name, reject, resolve, showErrors)); | |
} catch (error) { | |
callback(name, reject, resolve, showErrors)(error, null); | |
} | |
}) | |
); | |
} | |
if (arguments.length === 4) { | |
return from( | |
new Promise((resolve, reject) => { | |
try { | |
service[name](arguments[0], arguments[1], arguments[2], arguments[3], callback(name, reject, resolve, showErrors)); | |
} catch (error) { | |
callback(name, reject, resolve, showErrors)(error, null); | |
} | |
}) | |
); | |
} | |
// эта штука не работает, пришлось вызывать явно - выше ифы | |
return from( | |
new Promise((resolve, reject) => { | |
try { | |
service[name].apply(null, [...Array.from(arguments), callback(name, reject, resolve, showErrors)]); | |
} catch (error) { | |
callback(name, reject, resolve, showErrors)(error, null); | |
} | |
}) | |
); | |
}; | |
} | |
} | |
) as T; | |
function callback(name: string | number | symbol, reject: (reason?: any) => void, resolve: (value?: unknown) => void, showCallbackErrors: boolean): any { | |
return (err, res) => { | |
setTimeout(() => { | |
if (err) { | |
if (showCallbackErrors) { | |
console.error(`Error in run method "${String(name)}"`); | |
} | |
reject(err); | |
} else { | |
resolve(res); | |
} | |
}, 1000); | |
}; | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment