[ADD] service account authentication from input object

Author: Niurmiguel

LICENSE

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+
+MIT License
+
+Copyright (c) 2021 Pavel Fedyukovich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# googleads-node-lib

lib/auth/googleSACredential.ts

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+import { JSONClient } from 'google-auth-library/build/src/auth/googleauth';
+import { GoogleAuth, JWTInput, RefreshOptions } from 'google-auth-library';
+import { SCOPES } from '@common/constants';
+
+type ScopeOptions = keyof typeof SCOPES;
+
+export class googleSACredential {
+  private _json: string | JWTInput;
+  private _scopes: ScopeOptions[];
+  private _options: RefreshOptions | undefined;
+  protected auth: JSONClient;
+
+  constructor(
+    json: string | JWTInput,
+    scopes: ScopeOptions[],
+    options?: RefreshOptions,
+  ) {
+    if (!json) {
+      throw new Error("'json' must be set when using service account flow.");
+    }
+
+    if (!scopes)
+      throw new Error("'scopes' must be set when using service account flow.");
+
+    this._json = json;
+    this._scopes = scopes;
+    this._options = options;
+
+    this.build();
+  }
+
+  private async build() {
+    const scopes = SCOPES as Record<string, string>;
+
+    let json = this._json as JWTInput;
+
+    if (typeof this._json === 'string') {
+      json = JSON.parse(this._json);
+    }
+
+    this.auth = new GoogleAuth({
+      scopes: this._scopes.map((scope) => scopes[scope]),
+    }).fromJSON(json, this._options);
+  }
+
+  async getToken() {
+    return await (
+      await this.auth.getAccessToken()
+    ).token;
+  }
+}

lib/auth/index.ts

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+export { googleSACredential } from './googleSACredential';

lib/common/constants/index.ts

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+export const SCOPES = {
+  adwords: 'https://www.googleapis.com/auth/adwords',
+  ad_manager: 'https://www.googleapis.com/auth/dfp',
+};

lib/index.ts

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+export { googleSACredential } from './auth';