feat: Add Google Chat API quickstart (#845)

Co-authored-by: pierrick <pierrick@google.com>

chat/quickstart/README.md

@@ -0,0 +1,16 @@
+# Google Chat Node.js Quickstart
+
+Complete the steps described in the [quickstart instructions](
+https://developers.google.com/workspace/chat/api/guides/quickstart/nodejs),
+and in about five minutes you'll have a simple Node.js command-line
+application that makes requests to the Google Chat API.
+
+## Install
+
+`npm install`
+
+## Run
+
+After following the quickstart setup instructions, run the sample:
+
+`node .`

chat/quickstart/index.js

@@ -0,0 +1,119 @@
+/**
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// [START chat_quickstart]
+
+const fs = require('fs').promises;
+const path = require('path');
+const process = require('process');
+const {authenticate} = require('@google-cloud/local-auth');
+const {ChatServiceClient} = require('@google-apps/chat');
+const {auth} = require('google-auth-library');
+
+// If modifying these scopes, delete token.json.
+const SCOPES = ['https://www.googleapis.com/auth/chat.spaces.readonly'];
+
+// The file token.json stores the user's access and refresh tokens, and is
+// created automatically when the authorization flow completes for the first
+// time.
+const TOKEN_PATH = path.join(process.cwd(), 'token.json');
+const CREDENTIALS_PATH = path.join(process.cwd(), 'credentials.json');
+
+/**
+ * Reads previously authorized credentials from the save file.
+ *
+ * @return {Promise<OAuth2Client|null>}
+ */
+async function loadSavedCredentialsIfExist() {
+  try {
+    const content = await fs.readFile(TOKEN_PATH);
+    const credentials = JSON.parse(content);
+    return auth.fromJSON(credentials);
+  } catch (err) {
+    console.log(err);
+    return null;
+  }
+}
+
+/**
+ * Serializes credentials to a file compatible with GoogleAuth.fromJSON.
+ *
+ * @param {OAuth2Client} client
+ * @return {Promise<void>}
+ */
+async function saveCredentials(client) {
+  const content = await fs.readFile(CREDENTIALS_PATH);
+  const keys = JSON.parse(content);
+  const key = keys.installed || keys.web;
+  const payload = JSON.stringify({
+    type: 'authorized_user',
+    client_id: key.client_id,
+    client_secret: key.client_secret,
+    refresh_token: client.credentials.refresh_token,
+  });
+  await fs.writeFile(TOKEN_PATH, payload);
+}
+
+/**
+ * Load or request or authorization to call APIs.
+ *
+ * @return {Promise<OAuth2Client>}
+ */
+async function authorize() {
+  let client = await loadSavedCredentialsIfExist();
+  if (client) {
+    return client;
+  }
+  client = await authenticate({
+    scopes: SCOPES,
+    keyfilePath: CREDENTIALS_PATH,
+  });
+  if (client.credentials) {
+    await saveCredentials(client);
+  }
+  return client;
+}
+
+/**
+ * Lists spaces with user credential.
+ * @param {OAuth2Client} authClient An authorized OAuth2 client.
+ */
+async function listSpaces(authClient) {
+  // Create a client
+  const chatClient = new ChatServiceClient({
+    authClient: authClient,
+    scopes: SCOPES,
+  });
+
+  // Initialize request argument(s)
+  const request = {
+    // Filter spaces by space type (SPACE or GROUP_CHAT or DIRECT_MESSAGE)
+    filter: 'space_type = "SPACE"'
+  };
+
+  // Make the request
+  const pageResult = chatClient.listSpacesAsync(request);
+
+  // Handle the response. Iterating over pageResult will yield results and
+  // resolve additional pages automatically.
+  for await (const response of pageResult) {
+    console.log(response);
+  }
+}
+
+authorize().then(listSpaces).catch(console.error);
+
+// [END chat_quickstart]