Merge pull request #705 from hypothesis/replace-inherits-with-classes

Replace "inherits" package with ES 2015 class inheritance

package.json

@@ -57,7 +57,6 @@
     "gulp-sourcemaps": "^1.6.0",
     "gulp-util": "^3.0.7",
     "hammerjs": "^2.0.4",
-    "inherits": "^2.0.1",
     "isparta": "^4.0.0",
     "istanbul": "^0.4.5",
     "jquery": "^3.2.1",

src/sidebar/components/test/sidebar-content-test.js

 'use strict';
 
 var angular = require('angular');
-var inherits = require('inherits');
 var proxyquire = require('proxyquire');
 var EventEmitter = require('tiny-emitter');
 
@@ -9,7 +8,11 @@ var events = require('../../events');
 var noCallThru = require('../../../shared/test/util').noCallThru;
 
 var searchClients;
-function FakeSearchClient(searchFn, opts) {
+
+class FakeSearchClient extends EventEmitter {
+  constructor(searchFn, opts) {
+    super();
+
     assert.ok(searchFn);
     searchClients.push(this);
     this.cancel = sinon.stub();
@@ -26,15 +29,17 @@ function FakeSearchClient(searchFn, opts) {
 
       this.emit('end');
     });
+  }
 }
-inherits(FakeSearchClient, EventEmitter);
 
-function FakeRootThread() {
+class FakeRootThread extends EventEmitter {
+  constructor() {
+    super();
     this.thread = sinon.stub().returns({
       totalChildren: 0,
     });
+  }
 }
-inherits(FakeRootThread, EventEmitter);
 
 describe('sidebar.components.sidebar-content', function () {
   var $rootScope;

src/sidebar/components/test/stream-content-test.js

 'use strict';
 
 var angular = require('angular');
-var inherits = require('inherits');
 var EventEmitter = require('tiny-emitter');
 
-function FakeRootThread() {
+class FakeRootThread extends EventEmitter {
+  constructor() {
+    super();
     this.thread = sinon.stub();
+  }
 }
-inherits(FakeRootThread, EventEmitter);
 
 describe('StreamContentController', function () {
   var $componentController;

src/sidebar/components/test/thread-list-test.js

@@ -3,7 +3,6 @@
 var angular = require('angular');
 
 var EventEmitter = require('tiny-emitter');
-var inherits = require('inherits');
 var immutable = require('seamless-immutable');
 
 var events = require('../../events');
@@ -43,7 +42,9 @@ var threadFixtures = immutable({
 var fakeVirtualThread;
 var fakeSettings = {};
 
-function FakeVirtualThreadList($scope, $window, rootThread, options) {
+class FakeVirtualThreadList extends EventEmitter {
+  constructor($scope, $window, rootThread, options) {
+    super();
 
     fakeVirtualThread = this; // eslint-disable-line consistent-this
 
@@ -64,8 +65,8 @@ function FakeVirtualThreadList($scope, $window, rootThread, options) {
     this.yOffsetOf = function () {
       return 42;
     };
+  }
 }
-inherits(FakeVirtualThreadList, EventEmitter);
 
 describe('threadList', function () {
   var threadListContainers;

src/sidebar/search-client.js

 'use strict';
 
 var EventEmitter = require('tiny-emitter');
-var inherits = require('inherits');
 
 /**
  * Client for the Hypothesis search API.
  *
  * SearchClient handles paging through results, canceling search etc.
- *
+ */
+class SearchClient extends EventEmitter {
+  /**
    * @param {Object} searchFn - Function for querying the search API
    * @param {Object} opts - Search options
- * @constructor
    */
-function SearchClient(searchFn, opts) {
+  constructor(searchFn, opts) {
+    super();
     opts = opts || {};
 
     var DEFAULT_CHUNK_SIZE = 200;
@@ -24,10 +25,9 @@ function SearchClient(searchFn, opts) {
       this._incremental = true;
     }
     this._canceled = false;
-}
-inherits(SearchClient, EventEmitter);
+  }
 
-SearchClient.prototype._getBatch = function (query, offset) {
+  _getBatch(query, offset) {
     var searchQuery = Object.assign({
       limit: this._chunkSize,
       offset: offset,
@@ -75,9 +75,9 @@ SearchClient.prototype._getBatch = function (query, offset) {
       }
       self.emit('end');
     });
-};
+  }
 
-/**
+  /**
    * Perform a search against the Hypothesis API.
    *
    * Emits a 'results' event with an array of annotations as they become
@@ -87,18 +87,19 @@ SearchClient.prototype._getBatch = function (query, offset) {
    * Emits an 'error' event if the search fails.
    * Emits an 'end' event once the search completes.
    */
-SearchClient.prototype.get = function (query) {
+  get(query) {
     this._results = [];
     this._getBatch(query, 0);
-};
+  }
 
-/**
+  /**
    * Cancel the current search and emit the 'end' event.
    * No further events will be emitted after this.
    */
-SearchClient.prototype.cancel = function () {
+  cancel() {
     this._canceled = true;
     this.emit('end');
-};
+  }
+}
 
 module.exports = SearchClient;

src/sidebar/services/test/streamer-test.js

 'use strict';
 
 var EventEmitter = require('tiny-emitter');
-var inherits = require('inherits');
 var proxyquire = require('proxyquire');
 
 var events = require('../../events');
@@ -42,7 +41,10 @@ var fixtures = {
 // the most recently created FakeSocket instance
 var fakeWebSocket = null;
 
-function FakeSocket(url) {
+class FakeSocket extends EventEmitter {
+  constructor(url) {
+    super();
+
     fakeWebSocket = this; // eslint-disable-line consistent-this
 
     this.url = url;
@@ -62,8 +64,8 @@ function FakeSocket(url) {
     this.close = function () {
       this.didClose = true;
     };
+  }
 }
-inherits(FakeSocket, EventEmitter);
 
 describe('Streamer', function () {
   var fakeAnnotationMapper;

src/sidebar/virtual-thread-list.js

@@ -2,7 +2,6 @@
 
 var EventEmitter = require('tiny-emitter');
 var debounce = require('lodash.debounce');
-var inherits = require('inherits');
 
 /**
  * @typedef Options
@@ -26,13 +25,17 @@ var inherits = require('inherits');
  * applications this also helps significantly with UI responsiveness by limiting
  * the number of watchers (functions created by template expressions or
  * '$scope.$watch' calls) that have to be run on every '$scope.$digest()' cycle.
- *
+ */
+class VirtualThreadList extends EventEmitter {
+  /*
    * @param {Window} container - The Window displaying the list of annotation threads.
    * @param {Thread} rootThread - The initial Thread object for the top-level
    *        threads.
    * @param {Options} options
    */
-function VirtualThreadList($scope, window_, rootThread, options) {
+  constructor($scope, window_, rootThread, options) {
+    super();
+
     var self = this;
 
     this._rootThread = rootThread;
@@ -56,35 +59,34 @@ function VirtualThreadList($scope, window_, rootThread, options) {
       this.scrollRoot.removeEventListener('scroll', debouncedUpdate);
       this.window.removeEventListener('resize', debouncedUpdate);
     };
-}
-inherits(VirtualThreadList, EventEmitter);
+  }
 
-/**
+  /**
    * Detach event listeners and clear any pending timeouts.
    *
    * This should be invoked when the UI view presenting the virtual thread list
    * is torn down.
    */
-VirtualThreadList.prototype.detach = function () {
+  detach() {
     this._detach();
-};
+  }
 
-/**
+  /**
    * Sets the root thread containing all conversations matching the current
    * filters.
    *
    * This should be called with the current Thread object whenever the set of
    * matching annotations changes.
    */
-VirtualThreadList.prototype.setRootThread = function (thread) {
+  setRootThread(thread) {
     if (thread === this._rootThread) {
       return;
     }
     this._rootThread = thread;
     this._updateVisibleThreads();
-};
+  }
 
-/**
+  /**
    * Sets the actual height for a thread.
    *
    * When calculating the amount of space required for offscreen threads,
@@ -94,22 +96,22 @@ VirtualThreadList.prototype.setRootThread = function (thread) {
    * @param {string} id - The annotation ID or $tag
    * @param {number} height - The height of the annotation thread.
    */
-VirtualThreadList.prototype.setThreadHeight = function (id, height) {
+  setThreadHeight(id, height) {
     if (isNaN(height) || height <= 0) {
       throw new Error('Invalid thread height %d', height);
     }
     this._heights[id] = height;
-};
+  }
 
-VirtualThreadList.prototype._height = function (id) {
+  _height(id) {
     // Default guess of the height required for a threads that have not been
     // measured
     var DEFAULT_HEIGHT = 200;
     return this._heights[id] || DEFAULT_HEIGHT;
-};
+  }
 
-/** Return the vertical offset of an annotation card from the top of the list. */
-VirtualThreadList.prototype.yOffsetOf = function (id) {
+  /** Return the vertical offset of an annotation card from the top of the list. */
+  yOffsetOf(id) {
     var self = this;
     var allThreads = this._rootThread.children;
     var matchIndex = allThreads.findIndex(function (thread) {
@@ -121,15 +123,15 @@ VirtualThreadList.prototype.yOffsetOf = function (id) {
     return allThreads.slice(0, matchIndex).reduce(function (offset, thread) {
       return offset + self._height(thread.id);
     }, 0);
-};
+  }
 
-/**
+  /**
    * Recalculates the set of visible threads and estimates of the amount of space
    * required for offscreen threads above and below the viewport.
    *
    * Emits a `changed` event with the recalculated set of visible threads.
    */
-VirtualThreadList.prototype._updateVisibleThreads = function () {
+  _updateVisibleThreads() {
     // Space above the viewport in pixels which should be considered 'on-screen'
     // when calculating the set of visible threads
     var MARGIN_ABOVE = 800;
@@ -198,6 +200,7 @@ VirtualThreadList.prototype._updateVisibleThreads = function () {
       visibleThreads: visibleThreads,
       invisibleThreads: invisibleThreads,
     });
-};
+  }
+}
 
 module.exports = VirtualThreadList;

src/sidebar/websocket.js

@@ -2,7 +2,6 @@
 
 var retry = require('retry');
 var EventEmitter = require('tiny-emitter');
-var inherits = require('inherits');
 
 // see https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent
 var CLOSE_NORMAL = 1000;
@@ -19,7 +18,10 @@ var RECONNECT_MIN_DELAY = 1000;
  * - Uses the standard EventEmitter API for reporting open, close, error
  *   and message events.
  */
-function Socket(url) {
+class Socket extends EventEmitter {
+  constructor(url) {
+    super();
+
     var self = this;
 
     // queue of JSON objects which have not yet been submitted
@@ -125,8 +127,7 @@ function Socket(url) {
     };
 
     connect();
+  }
 }
 
-inherits(Socket, EventEmitter);
-
 module.exports = Socket;