Adding some logging for the precache details

.eslintrc.js

@@ -35,5 +35,10 @@ module.exports = {
       'max-len': 0,
       'no-invalid-this': 0,
     },
+  }, {
+    files: ['gulp-tasks/*.js'],
+    rules: {
+      'no-console': 0,
+    },
   }],
 };

packages/workbox-precaching/src/lib/controllers/base-cache-manager.js

@@ -1,5 +1,6 @@
 import {RequestWrapper} from '../../../../workbox-runtime-caching/src/index';
 import WorkboxError from '../../../../../lib/workbox-error';
+import logHelper from '../../../../../lib/log-helper';
 
 /**
  * This class handles the shared logic for caching revisioned and unrevisioned
@@ -111,8 +112,8 @@ class BaseCacheManager {
    * This method will go through each asset added to the cache list and
    * fetch and update the cache for assets which have a new revision hash.
    *
-   * @return {Promise} The promise resolves when all the desired assets are
-   * cached and up -to-date.
+   * @return {Promise<Array<Object>>} The promise resolves when all the
+   * desired assets are cached and up -to-date.
    */
   async install() {
     if (this._entriesToCache.size === 0) {
@@ -136,13 +137,20 @@ class BaseCacheManager {
    *
    * @private
    * @param {BaseCacheEntry} precacheEntry The entry to fetch and cache.
-   * @return {Promise} Returns a promise that resolves once the entry is fetched
-   * and cached.
+   * @return {Promise<Object>} Returns a promise that resolves once the entry
+   * has been fetched and cached or skipped if no update is needed. The
+   * promise resolved with details of the entry and whether it was
+   * updated or not.
    */
   async _cacheEntry(precacheEntry) {
     const isCached = await this._isAlreadyCached(precacheEntry);
+    const precacheDetails = {
+      url: precacheEntry.request.url,
+      revision: precacheEntry.revision,
+      wasUpdated: !isCached,
+    };
     if (isCached) {
-      return;
+      return precacheDetails;
     }
 
     try {
@@ -153,7 +161,8 @@ class BaseCacheManager {
         cleanRedirects: true,
       });
 
-      return this._onEntryCached(precacheEntry);
+      await this._onEntryCached(precacheEntry);
+      return precacheDetails;
     } catch (err) {
       throw new WorkboxError('request-not-cached', {
         url: precacheEntry.request.url,

packages/workbox-precaching/src/lib/controllers/revisioned-cache-manager.js

@@ -223,6 +223,71 @@ class RevisionedCacheManager extends BaseCacheManager {
       return this._close();
     });
   }
+
+  /**
+   * Given an array of objects with a 'url', 'revision' value this
+   * method will create a friendly string to log.
+   * @private
+   * @param {Array<Object>} allCacheDetails
+   * @return {String} A log friendly string.
+   */
+  _createLogFriendlyString(allCacheDetails) {
+    let stringVersion = `\n`;
+    allCacheDetails.forEach((cacheDetails) => {
+      stringVersion += `    URL: '${cacheDetails.url}' Revision: ` +
+        `'${cacheDetails.revision}'\n`;
+    });
+    return stringVersion;
+  }
+
+  /**
+   * This method will go through each asset added to the cache list and
+   * fetch and update the cache for assets which have a new revision hash.
+   *
+   * @return {Promise<Array<Object>>} The promise resolves when all the
+   * desired assets are cached and up -to-date.
+   */
+  install() {
+    return super.install()
+    .then((allCacheDetails) => {
+      const updatedCacheDetails = [];
+      const notUpdatedCacheDetails = [];
+      allCacheDetails.forEach((cacheDetails) => {
+        if (cacheDetails.wasUpdated) {
+          updatedCacheDetails.push({
+            url: cacheDetails.url,
+            revision: cacheDetails.revision,
+          });
+        } else {
+          notUpdatedCacheDetails.push({
+            url: cacheDetails.url,
+            revision: cacheDetails.revision,
+          });
+        }
+      });
+
+      const logData = {};
+      if (updatedCacheDetails.length > 0) {
+        logData['New / Updated Precache URL\'s'] =
+          this._createLogFriendlyString(updatedCacheDetails);
+      }
+
+      if (notUpdatedCacheDetails.length > 0) {
+        logData['Up-to-date Precache URL\'s'] =
+          this._createLogFriendlyString(notUpdatedCacheDetails);
+      }
+
+      logHelper.log({
+        message: `Precache Details: ${updatedCacheDetails.length} requests ` +
+        `were added or updated and ` +
+        `${notUpdatedCacheDetails.length} request are already ` +
+        `cached and up-to-date.`,
+        data: logData,
+      });
+
+      return allCacheDetails;
+    });
+  }
 }
 
 export default RevisionedCacheManager;

packages/workbox-precaching/test/static/skip-and-claim.js

@@ -1,3 +1,5 @@
+workbox.logLevel = self.workbox.LOG_LEVEL.verbose;
+
 self.addEventListener('install', (event) => event.waitUntil(self.skipWaiting()));
 
 self.addEventListener('activate', (event) => event.waitUntil(self.clients.claim()));

packages/workbox-precaching/test/sw/revisioned-caching.js

@@ -1,6 +1,8 @@
 importScripts('/__test/mocha/sw-utils.js');
 importScripts('/__test/bundle/workbox-precaching');
 
+workbox.logLevel = self.workbox.LOG_LEVEL.verbose;
+
 describe('sw/revisioned-caching()', function() {
   let cacheManager;
 
@@ -240,7 +242,20 @@ describe('sw/revisioned-caching()', function() {
       return {url, revision: 'dummy-revision'};
     });
     cacheManager.addToCacheList({revisionedFiles: firstRevisionedFiles});
-    await cacheManager.install();
+
+    const firstCacheDetails = await cacheManager.install();
+    let updatedCount = 0;
+    let notUpdatedCount = 0;
+    firstCacheDetails.forEach((cacheDetails) => {
+      if (cacheDetails.wasUpdated) {
+        updatedCount++;
+      } else {
+        notUpdatedCount++;
+      }
+    });
+    expect(updatedCount).to.equal(3);
+    expect(notUpdatedCount).to.equal(0);
+
     await cacheManager.cleanup();
 
     const firstIdbUrls = await cacheManager._revisionDetailsModel._idbHelper.getAllKeys();
@@ -254,7 +269,20 @@ describe('sw/revisioned-caching()', function() {
       return {url, revision: 'dummy-revision'};
     });
     secondCacheManager.addToCacheList({revisionedFiles: secondRevisionedFiles});
-    await secondCacheManager.install();
+
+    const secondCacheDetails = await secondCacheManager.install();
+    updatedCount = 0;
+    notUpdatedCount = 0;
+    secondCacheDetails.forEach((cacheDetails) => {
+      if (cacheDetails.wasUpdated) {
+        updatedCount++;
+      } else {
+        notUpdatedCount++;
+      }
+    });
+    expect(updatedCount).to.equal(0);
+    expect(notUpdatedCount).to.equal(2);
+
     await secondCacheManager.cleanup();
 
     const secondIdbUrls = await secondCacheManager._revisionDetailsModel._idbHelper.getAllKeys();