build: payload github status

* Show payload deta on PRs using the Github Statuses API.

tools/gulp/tasks/payload.ts

@@ -2,16 +2,18 @@ import {task} from 'gulp';
 import {join} from 'path';
 import {statSync} from 'fs';
 import {DIST_ROOT} from '../build-config';
-import {spawnSync} from 'child_process';
-import {isTravisMasterBuild} from '../util/travis-ci';
+import {isTravisBuild, isTravisMasterBuild} from '../util/travis-ci';
 import {openFirebaseDashboardApp} from '../util/firebase';
 
+// These imports lack of type definitions.
+const request = require('request');
+
 const bundlesDir = join(DIST_ROOT, 'bundles');
 
 /** Task which runs test against the size of material. */
-task('payload', ['material:clean-build'], () => {
+task('payload', ['material:clean-build'], async () => {
 
-  let results = {
+  const results = {
     timestamp: Date.now(),
     // Material bundles
     material_umd: getBundleSize('material.umd.js'),
@@ -28,9 +30,21 @@ task('payload', ['material:clean-build'], () => {
   // Print the results to the console, so we can read it from the CI.
   console.log('Payload Results:', JSON.stringify(results, null, 2));
 
-  // Publish the results to firebase when it runs on Travis and not as a PR.
-  if (isTravisMasterBuild()) {
-    return publishResults(results);
+  if (isTravisBuild()) {
+    // Open a connection to Firebase. For PRs the connection will be established as a guest.
+    const firebaseApp = openFirebaseDashboardApp(!isTravisMasterBuild());
+    const database = firebaseApp.database();
+    const currentSha = process.env['TRAVIS_PULL_REQUEST_SHA'] || process.env['TRAVIS_COMMIT'];
+
+    // Upload the payload results and calculate the payload diff in parallel. Otherwise the
+    // payload task will take much more time inside of Travis builds.
+    await Promise.all([
+      uploadPayloadResults(database, currentSha, results),
+      calculatePayloadDiff(database, currentSha, results)
+    ]);
+
+    // Disconnect database connection because Firebase otherwise prevents Gulp from exiting.
+    firebaseApp.delete();
   }
 
 });
@@ -45,14 +59,73 @@ function getFilesize(filePath: string) {
   return statSync(filePath).size / 1000;
 }
 
-/** Publishes the given results to the firebase database. */
-function publishResults(results: any) {
-  const latestSha = spawnSync('git', ['rev-parse', 'HEAD']).stdout.toString().trim();
-  const dashboardApp = openFirebaseDashboardApp();
-  const database = dashboardApp.database();
+/**
+ * Calculates the difference between the last and current library payload.
+ * The results will be published as a commit status on Github.
+ */
+async function calculatePayloadDiff(database: any, currentSha: string, currentPayload: any) {
+  const authToken = process.env['FIREBASE_ACCESS_TOKEN'];
+
+  if (!authToken) {
+    console.error('Cannot calculate Payload diff because there is no "FIREBASE_ACCESS_TOKEN" ' +
+      'environment variable set.');
+    return;
+  }
+
+  const previousPayload = await getLastPayloadResults(database);
+
+  // Calculate library sizes by combining the CDK and Material FESM 2015 bundles.
+  const previousSize = previousPayload.cdk_fesm_2015 + previousPayload.material_fesm_2015;
+  const currentSize = currentPayload.cdk_fesm_2015 + currentPayload.material_fesm_2015;
+  const deltaSize = currentSize - previousSize;
+
+  // Update the Github status of the current commit by sending a request to the dashboard
+  // firebase http trigger function.
+  await updateGithubStatus(currentSha, deltaSize, authToken);
+}
+
+/**
+ * Updates the Github status of a given commit by sending a request to a Firebase function of
+ * the dashboard. The function has access to the Github repository and can set status for PRs too.
+ */
+async function updateGithubStatus(commitSha: string, payloadDiff: number, authToken: string) {
+  const options = {
+    url: 'https://us-central1-material2-dashboard.cloudfunctions.net/payloadGithubStatus',
+    headers: {
+      'User-Agent': 'Material2/PayloadTask',
+      'auth-token': authToken,
+      'commit-sha': commitSha,
+      'commit-payload-diff': payloadDiff
+    }
+  };
+
+  return new Promise((resolve, reject) => {
+    request(options, (err: any, response: any, body: string) => {
+      if (err) {
+        reject(`Dashboard Error ${err.toString()}`);
+      } else {
+        console.info('Dashboard Response: ', JSON.parse(body).message);
+        resolve(response.statusCode);
+      }
+    });
+  });
+}
+
+/** Uploads the current payload results to the Dashboard database. */
+async function uploadPayloadResults(database: any, currentSha: string, currentPayload: any) {
+  if (isTravisMasterBuild()) {
+    await database.ref('payloads').child(currentSha).set(currentPayload);
+  }
+}
+
+/** Gets the last payload uploaded from previous Travis builds. */
+async function getLastPayloadResults(database: admin.database.Database) {
+  const snapshot = await database.ref('payloads')
+    .orderByChild('timestamp')
+    .limitToLast(1)
+    .once('value');
 
-  // Write the results to the payloads object with the latest Git SHA as key.
-  return database.ref('payloads').child(latestSha).set(results)
-    .catch((err: any) => console.error(err))
-    .then(() => dashboardApp.delete());
+  // The value of the DataSnapshot is an object with the SHA as a key. Only return the
+  // value of the object because the SHA is not necessary.
+  return snapshot.val()[Object.keys(snapshot.val())[0]];
 }

tools/gulp/util/firebase.ts

@@ -6,18 +6,26 @@ const cloudStorage = require('@google-cloud/storage');
 const screenshotFirebaseConfig = require('../../screenshot-test/functions/config.json');
 
 /** Opens a connection to the Firebase dashboard app. */
-export function openFirebaseDashboardApp() {
+export function openFirebaseDashboardApp(asGuest = false) {
+  const databaseURL = 'https://material2-board.firebaseio.com';
+
+  // In some situations the service account credentials are not available and authorizing as
+  // a guest works fine. For example in Pull Requests the payload task just wants to read data.
+  if (asGuest) {
+    return firebase.initializeApp({ databaseURL });
+  }
+
   // Initialize the Firebase application with firebaseAdmin credentials.
   // Credentials need to be for a Service Account, which can be created in the Firebase console.
   return firebaseAdmin.initializeApp({
+    databaseURL,
     credential: firebaseAdmin.credential.cert({
       project_id: 'material2-board',
       client_email: 'material2-board@appspot.gserviceaccount.com',
       // In Travis CI the private key will be incorrect because the line-breaks are escaped.
       // The line-breaks need to persist in the service account private key.
       private_key: decode(process.env['MATERIAL2_BOARD_FIREBASE_SERVICE_KEY'])
     }),
-    databaseURL: 'https://material2-board.firebaseio.com'
   });
 }
 

tools/gulp/util/travis-ci.ts

@@ -2,3 +2,7 @@
 export function isTravisMasterBuild() {
   return process.env['TRAVIS_PULL_REQUEST'] === 'false';
 }
+
+export function isTravisBuild() {
+  return process.env['TRAVIS'] === 'true';
+}