adds prependManifest and PrependManifestPlugin

packages/workbox-build/src/index.js

@@ -4,6 +4,7 @@ const generateSW = require('./lib/generate-sw');
 const getFileManifestEntries = require('./lib/get-file-manifest-entries');
 const generateFileManifest = require('./lib/generate-file-manifest');
 const injectManifest = require('./lib/inject-manifest');
+const prependManifest = require('./lib/prepend-manifest');
 
 /**
  * # workbox-build
@@ -88,4 +89,5 @@ module.exports = {
   generateFileManifest,
   getFileManifestEntries,
   injectManifest,
+  prependManifest,
 };

packages/workbox-build/src/lib/errors.js

@@ -61,6 +61,8 @@ module.exports = {
     `an object with string key value pairs.`,
   'invalid-inject-manifest-arg': `The input to 'injectManifest()' must be ` +
     `be an object.`,
+  'invalid-prepend-manifest-arg': `The input to 'prependManifest()' must be ` +
+    `be an object.`,
   'injection-point-not-found': `Unable to find a place to inject the ` +
     `manifest. Please ensure that you have 'workboxSW.precache([])' ` +
     `somewhere in your service worker file.`,

packages/workbox-build/src/lib/generate-file-manifest.js

@@ -2,6 +2,7 @@
 
 const getFileManifestEntries = require('./get-file-manifest-entries');
 const writeFileManifest = require('./utils/write-file-manifest');
+const isValidInput = require('./utils/is-valid-input');
 const errors = require('./errors');
 
 /**
@@ -65,7 +66,7 @@ const errors = require('./errors');
  * @memberof module:workbox-build
  */
 const generateFileManifest = (input) => {
-  if (!input || typeof input !== 'object' || Array.isArray(input)) {
+  if (!isValidInput(input)) {
     return Promise.reject(
       new Error(errors['invalid-generate-file-manifest-arg']));
   }

packages/workbox-build/src/lib/generate-sw.js

@@ -2,6 +2,7 @@
 
 const path = require('path');
 const copyWorkboxSW = require('./utils/copy-workbox-sw');
+const isValidInput = require('./utils/is-valid-input');
 const getFileManifestEntries = require('./get-file-manifest-entries');
 const writeServiceWorker = require('./write-sw');
 const errors = require('./errors');
@@ -99,7 +100,7 @@ const constants = require('./constants');
  * @memberof module:workbox-build
  */
 const generateSW = function(input) {
-  if (!input || typeof input !== 'object' || Array.isArray(input)) {
+  if (!isValidInput(input)) {
     return Promise.reject(new Error(errors['invalid-generate-sw-input']));
   }
 

packages/workbox-build/src/lib/get-file-manifest-entries.js

@@ -5,6 +5,7 @@ const filterFiles = require('./utils/filter-files');
 const getCompositeDetails = require('./utils/get-composite-details');
 const getFileDetails = require('./utils/get-file-details');
 const getStringDetails = require('./utils/get-string-details');
+const isValidInput = require('./utils/is-valid-input');
 const constants = require('./constants');
 
 /**
@@ -55,7 +56,7 @@ const constants = require('./constants');
  * @memberof module:workbox-build
  */
 const getFileManifestEntries = (input) => {
-  if (!input || typeof input !== 'object' || Array.isArray(input)) {
+  if (!isValidInput(input)) {
     return Promise.reject(
       new Error(errors['invalid-get-manifest-entries-input']));
   }

packages/workbox-build/src/lib/inject-manifest.js

@@ -4,6 +4,7 @@ const fs = require('fs');
 const mkdirp = require('mkdirp');
 const path = require('path');
 
+const isValidInput = require('./utils/is-valid-input');
 const getFileManifestEntries = require('./get-file-manifest-entries');
 const errors = require('./errors');
 
@@ -66,7 +67,7 @@ const errors = require('./errors');
  * @memberof module:workbox-build
  */
 const injectManifest = (input) => {
-  if (!input || typeof input !== 'object' || Array.isArray(input)) {
+  if (!isValidInput(input)) {
     return Promise.reject(
       new Error(errors['invalid-inject-manifest-arg']));
   }
@@ -94,7 +95,7 @@ const injectManifest = (input) => {
         if (err) {
           return reject(
             new Error(
-              errors['unable-to-make-injection-directory'] +
+              errors['unable-to-make-sw-directory'] +
               ` '${err.message}'`
             )
           );

packages/workbox-build/src/lib/prepend-manifest.js

@@ -0,0 +1,102 @@
+'use strict';
+
+const fs = require('fs');
+const mkdirp = require('mkdirp');
+const path = require('path');
+
+const isValidInput = require('./utils/is-valid-input');
+const getFileManifestEntries = require('./get-file-manifest-entries');
+const errors = require('./errors');
+
+/**
+ * This method will read an existing service worker file and prepend it with
+ * an array of assets to precache. The array is assigned to
+ * `self.__file_manifest`. This allows the service worker to use the manifest
+ * for other purposes or mutate it before precaching.
+ *
+ * @param {Object} input
+ * @param {String} input.swSrc File path and name of the service worker file
+ * to read and inject the manifest into before writing to `swDest`.
+ * @param {String} input.globDirectory The directory you wish to run the
+ * `globPatterns` against.
+ * @param {Array<String>} input.globPatterns Files matching against any of
+ * these glob patterns will be included in the file manifest.
+ *
+ * Defaults to ['**\/*.{js,css}']
+ * @param {String|Array<String>} [input.globIgnores] Files matching against any
+ * of these glob patterns will be excluded from the file manifest, even if the
+ * file matches against a `globPatterns` pattern. Defaults to ignoring
+ * 'node_modules'.
+ * @param {Object<String,Array|String>} [input.templatedUrls]
+ * If a URL is rendered with templates on the server, its contents may
+ * depend on multiple files. This maps URLs to an array of file names, or to a
+ * string value, that uniquely determines the URL's contents.
+ * @param {String} [input.modifyUrlPrefix] An object of key value pairs
+ * where URL's starting with the key value will be replaced with the
+ * corresponding value.
+ * @param {number} [input.maximumFileSizeToCacheInBytes] This value can be used
+ * to determine the maximum size of files that will be precached.
+ *
+ * Defaults to 2MB.
+ * @param {RegExp} [input.dontCacheBustUrlsMatching] An optional regex that will
+ * return a URL string and exclude the revision details for urls matching this
+ * regex. Useful if you have assets with file revisions in the URL.
+ * @param {Array<ManifestTransform>} [input.manifestTransforms] A list of
+ * manifest transformations, which will be applied sequentially against the
+ * generated manifest. If `modifyUrlPrefix` or `dontCacheBustUrlsMatching` are
+ * also specified, their corresponding transformations will be applied first.
+ * @return {Promise} Resolves once the service worker has been written
+ * with the prepended precache list.
+ *
+ * @example <caption>Prepend a manifest of static assets, which could
+ * then be used with a service worker.</caption>
+ * const swBuild = require('workbox-build');
+ *
+ * swBuild.prependManifest({
+ *   globDirectory: './build/',
+ *   globPatterns: ['**\/*.{html,js,css}'],
+ *   globIgnores: ['admin.html'],
+ *   swSrc: './src/sw.js',
+ *   swDest: './build/sw.js',
+ *   manifestVariable: 'assetManifest',
+ * })
+ * .then(() => {
+ *   console.log('Build Manifest generated.');
+ * });
+ *
+ * @memberof module:workbox-build
+ */
+const prependManifest = (input) => {
+  if (!isValidInput(input)) {
+    return Promise.reject(
+      new Error(errors['invalid-prepend-manifest-arg']));
+  }
+
+  return getFileManifestEntries(input)
+  .then((manifestEntries) => {
+    let swFileContents = fs.readFileSync(input.swSrc, 'utf8');
+
+    const entriesString = JSON.stringify(manifestEntries, null, 2);
+    swFileContents =
+      `self.__file_manifest = ${entriesString};\n${swFileContents}`;
+
+    return new Promise((resolve, reject) => {
+      mkdirp(path.dirname(input.swDest), (err) => {
+        if (err) {
+          return reject(
+            new Error(
+              errors['unable-to-make-sw-directory'] +
+              ` '${err.message}'`
+            )
+          );
+        }
+        resolve();
+      });
+    })
+    .then(() => {
+      fs.writeFileSync(input.swDest, swFileContents);
+    });
+  });
+};
+
+module.exports = prependManifest;

packages/workbox-build/src/lib/utils/is-valid-input.js

@@ -0,0 +1,3 @@
+module.exports = (input) => input
+  && typeof input === 'object'
+  && !Array.isArray(input);

packages/workbox-build/test/node/prepend-manifest.js

@@ -0,0 +1,58 @@
+const path = require('path');
+const fs = require('fs');
+const fsExtra = require('fs-extra');
+const expect = require('chai').expect;
+
+const swBuild = require('../../build/index.js');
+
+describe(`Test Prepend Manifest`, function() {
+  let tmpDirectory;
+
+  before(function() {
+    tmpDirectory = fs.mkdtempSync(
+      path.join(__dirname, 'tmp-')
+    );
+  });
+
+  after(function() {
+    fsExtra.removeSync(tmpDirectory);
+  });
+
+  const TEST_INPUT_FILE = 'service-worker.js';
+  const expectedString = `self.__file_manifest = [
+  {
+    "url": "index.css",
+    "revision": "d41d8cd98f00b204e9800998ecf8427e"
+  },
+  {
+    "url": "index.html",
+    "revision": "d41d8cd98f00b204e9800998ecf8427e"
+  }
+];\n`;
+  it(`should be able to read and prepend service worker`, function() {
+    const swDest = path.join(tmpDirectory, `sw.js`);
+    return swBuild.prependManifest({
+      globDirectory: path.join(
+        __dirname,
+        '..',
+        'static',
+        'prepend-samples',
+        'assets',
+      ),
+      globPatterns: ['**/*.{html,css}'],
+      swSrc: path.join(
+        __dirname,
+        '..',
+        'static',
+        'prepend-samples',
+        TEST_INPUT_FILE,
+      ),
+      swDest,
+    })
+    .then(() => {
+      const fileOutput = fs.readFileSync(swDest).toString();
+      const manifestPart = fileOutput.substr(0, expectedString.length);
+      expect(manifestPart).to.equal(expectedString);
+    });
+  });
+});

packages/workbox-build/test/static/prepend-samples/service-worker.js

@@ -0,0 +1,2 @@
+const workboxSW = new WorkboxSW();
+workboxSW.precache([self.__file_manifest]);

packages/workbox-webpack-plugin/src/index.js

@@ -1,6 +1,7 @@
 const GenerateFileManifestPlugin = require('./lib/generate-file-manifest');
 const GenerateSWPlugin = require('./lib/generate-sw');
 const InjectManifestPlugin = require('./lib/inject-manifest');
+const PrependManifestPlugin = require('./lib/prepend-manifest');
 
 /**
  * Use one of the plugins to integrate a webpack project with
@@ -35,4 +36,5 @@ module.exports = {
   GenerateSWPlugin,
   GenerateFileManifestPlugin,
   InjectManifestPlugin,
+  PrependManifestPlugin,
 };

packages/workbox-webpack-plugin/src/lib/prepend-manifest.js

@@ -0,0 +1,70 @@
+const swBuild = require('workbox-build');
+const path = require('path');
+const BasePlugin = require('./base-plugin');
+const errors = require('./errors');
+
+/**
+ * An instance of this plugin prepends a file with the manifest assigned to
+ * `self.__file_manifest`. The manifest is generated using
+ * [workbox-build:getFileManifestEntries]{@link
+ * module:workbox-build.getFileManifestEntries}.
+ *
+ * @memberof module:workbox-webpack-plugin
+ */
+class PrependManifestPlugin extends BasePlugin {
+  /**
+   * Create a new instance of `PrependManifestPlugin`.
+   *
+   * @param {Object} [config] All the options as passed to
+   * [workbox-build:getFileManifestEntries]{@link
+   * module:workbox-build.injectManifest}. See
+   * [workbox-build:getFileManifestEntries]{@link
+   * module:workbox-build.injectManifest} for all possible options.
+   * @param {String} [config.swSrc] When invalid, compilation throws an error.
+   * @param {String} [config.swDest] Defaults to `%{outputPath}/sw.js`.
+   */
+  constructor(config) {
+    super(config);
+  }
+  /**
+   * @private
+   * @param {Object} compilation The [compilation](https://github.com/webpack/docs/wiki/how-to-write-a-plugin#accessing-the-compilation),
+   * passed from Webpack to this plugin.
+   * @throws Throws an error if `swSrc` option is invalid.
+   * @return {Object} The configuration for a given compilation.
+   */
+  getConfig(compilation) {
+    const config = super.getConfig(compilation);
+
+    if (!config.swSrc) {
+      throw new Error(errors['invalid-sw-src']);
+    }
+
+    if (!config.swDest) {
+      config.swDest = path.join(compilation.options.output.path, 'sw.js');
+    }
+
+    return config;
+  }
+  /**
+   * This method uses [workbox-build:injectManifest]{
+   * @link module:workbox-build.injectManifest} to generate a manifest file.
+   *
+   * @private
+   * @param {Object} compilation The [compilation](https://github.com/webpack/docs/wiki/how-to-write-a-plugin#accessing-the-compilation),
+   * @param {Function} [callback] function that must be invoked when handler
+   * finishes running.
+   */
+  handleAfterEmit(compilation, callback) {
+    try {
+      const config = this.getConfig(compilation, callback);
+      swBuild.prependManifest(config)
+        .then(() => callback())
+        .catch((e) => callback(e));
+    } catch (e) {
+      callback(e);
+    }
+  }
+}
+
+module.exports = PrependManifestPlugin;