Implement useOAuth

lib/GoogleSpreadsheet.js

@@ -20,8 +20,42 @@ const AUTH_MODES = {
   JWT: 'JWT',
   API_KEY: 'API_KEY',
   RAW_ACCESS_TOKEN: 'RAW_ACCESS_TOKEN',
+  OAUTH: 'OAUTH'
 };
 
+const ONE_MINUTE = 60000;
+
+const serializeParams = (params) => {
+  let options = "";
+  _.keys(params).forEach((key) => {
+    const isParamTypeObject = typeof params[key] === "object";
+    const isParamTypeArray = isParamTypeObject && params[key].length >= 0;
+    if (!isParamTypeObject)
+      options += `${key}=${encodeURIComponent(params[key])}&`;
+    if (isParamTypeObject && isParamTypeArray) {
+      _.each(params[key], (val) => {
+        options += `${key}=${encodeURIComponent(val)}&`;
+      });
+    }
+  });
+  return options ? options.slice(0, -1) : options;
+};
+
+const refreshToken = async ({ clientId, clientSecret, refreshToken }) => {
+  const url = "https://oauth2.googleapis.com/token";
+  const data = {
+    refresh_token: refreshToken,
+    client_id: clientId,
+    client_secret: clientSecret,
+    grant_type: "refresh_token",
+  };
+  const res = await Axios.post(url, serializeParams(data), {
+    headers: { "Content-Type": "application/x-www-form-urlencoded" },
+  });
+  return res.data;
+};
+
+
 class GoogleSpreadsheet {
   constructor(sheetId) {
     this.spreadsheetId = sheetId;
@@ -88,6 +122,12 @@ class GoogleSpreadsheet {
     this.accessToken = token;
   }
 
+  async useOAuthToken(creds, onRefreshTokens) {
+    this.authMode = AUTH_MODES.OAUTH;
+    this.oAuthCredentials = creds;
+    this.oAuthRefreshCallback = onRefreshTokens;
+  }
+
   // creds should be an object obtained by loading the json file google gives you
   // impersonateAs is an email of any user in the G Suite domain
   // (only works if service account has domain-wide delegation enabled)
@@ -133,6 +173,26 @@ class GoogleSpreadsheet {
       if (!this.apiKey) throw new Error('Please set API key');
       config.params = config.params || {};
       config.params.key = this.apiKey;
+    } else if (this.authMode === AUTH_MODES.OAUTH) {
+      const isExpired = !this.oAuthCredentials.expiresAt || this.oAuthCredentials.expiresAt < Date.now() - ONE_MINUTE * 2
+      if (isExpired) {
+        // refresh the token
+        const nextTokens = await refreshToken({
+          clientId: this.oAuthCredentials.clientId,
+          clientSecret: this.oAuthCredentials.clientSecret,
+          refreshToken: this.oAuthCredentials.refreshToken
+        })
+        this.oAuthCredentials.accessToken = nextTokens.access_token;
+        this.oAuthCredentials.refreshToken = nextTokens.refresh_token;
+        this.oAuthCredentials.expiresAt = Date.now() + nextTokens.expires_in * 1000;
+        await this.oAuthRefreshCallback({
+          accessToken: this.oAuthCredentials.accessToken,
+          refreshToken: this.oAuthCredentials.refreshToken,
+          expiresAt: this.oAuthCredentials.expiresAt
+        })
+      }
+
+      config.headers.Authorization = `Bearer ${this.oAuthCredentials.accessToken}`;
     } else {
       throw new Error('You must initialize some kind of auth before making any requests');
     }