Fix a number of minor code quality issues

Most of these are complaints from my IDE. Discovered by going through nearly every file looking for React warnings.

src/async-components/views/dialogs/EncryptedEventDialog.js

@@ -79,7 +79,7 @@ export default createReactClass({
     },
 
     onDeviceVerificationChanged: function(userId, device) {
-        if (userId == this.props.event.getSender()) {
+        if (userId === this.props.event.getSender()) {
             this.refreshDevice().then((dev) => {
                 this.setState({ device: dev });
             });

src/async-components/views/dialogs/eventindex/ManageEventIndexDialog.js

@@ -30,7 +30,7 @@ import EventIndexPeg from "../../../../indexing/EventIndexPeg";
 export default class ManageEventIndexDialog extends React.Component {
     static propTypes = {
         onFinished: PropTypes.func.isRequired,
-    }
+    };
 
     constructor(props) {
         super(props);
@@ -126,16 +126,12 @@ export default class ManageEventIndexDialog extends React.Component {
             import("./DisableEventIndexDialog"),
             null, null, /* priority = */ false, /* static = */ true,
         );
-    }
-
-    _onDone = () => {
-        this.props.onFinished(true);
-    }
+    };
 
     _onCrawlerSleepTimeChange = (e) => {
         this.setState({crawlerSleepTime: e.target.value});
         SettingsStore.setValue("crawlerSleepTime", null, SettingLevel.DEVICE, e.target.value);
-    }
+    };
 
     render() {
         let crawlerState;

src/components/structures/GroupView.js

@@ -433,7 +433,6 @@ export default createReactClass({
         this._matrixClient = MatrixClientPeg.get();
         this._matrixClient.on("Group.myMembership", this._onGroupMyMembership);
 
-        this._changeAvatarComponent = null;
         this._initGroupStore(this.props.groupId, true);
 
         this._dispatcherRef = dis.register(this._onAction);

src/components/structures/auth/SoftLogout.js

@@ -54,7 +54,7 @@ export default class SoftLogout extends React.Component {
 
         this.state = {
             loginView: LOGIN_VIEW.LOADING,
-            keyBackupNeeded: true, // assume we do while we figure it out (see componentWillMount)
+            keyBackupNeeded: true, // assume we do while we figure it out (see componentDidMount)
 
             busy: false,
             password: "",

src/components/views/dialogs/RoomSettingsDialog.js

@@ -41,7 +41,7 @@ export default class RoomSettingsDialog extends React.Component {
     }
 
     componentWillUnmount() {
-        dis.unregister(this._dispatcherRef);
+        if (this._dispatcherRef) dis.unregister(this._dispatcherRef);
     }
 
     _onAction = (payload) => {

src/components/views/elements/AppTile.js

@@ -161,7 +161,7 @@ export default class AppTile extends React.Component {
 
     componentWillUnmount() {
         // Widget action listeners
-        dis.unregister(this.dispatcherRef);
+        if (this.dispatcherRef) dis.unregister(this.dispatcherRef);
 
         // if it's not remaining on screen, get rid of the PersistedElement container
         if (!ActiveWidgetStore.getWidgetPersistence(this.props.id)) {

src/components/views/elements/LanguageDropdown.js

@@ -24,8 +24,8 @@ import SettingsStore from "../../../settings/SettingsStore";
 import { _t } from "../../../languageHandler";
 
 function languageMatchesSearchQuery(query, language) {
-    if (language.label.toUpperCase().indexOf(query.toUpperCase()) == 0) return true;
-    if (language.value.toUpperCase() == query.toUpperCase()) return true;
+    if (language.label.toUpperCase().includes(query.toUpperCase())) return true;
+    if (language.value.toUpperCase() === query.toUpperCase()) return true;
     return false;
 }
 

src/components/views/elements/Pill.js

@@ -158,7 +158,7 @@ const Pill = createReactClass({
     componentWillMount() {
         this._unmounted = false;
         this._matrixClient = MatrixClientPeg.get();
-        this.componentWillReceiveProps(this.props);
+        this.componentWillReceiveProps(this.props); // HACK: We shouldn't be calling lifecycle functions ourselves.
     },
 
     componentWillUnmount() {

src/components/views/rooms/AppsDrawer.js

@@ -71,7 +71,7 @@ export default createReactClass({
             MatrixClientPeg.get().removeListener('RoomState.events', this.onRoomStateEvents);
         }
         WidgetEchoStore.removeListener('update', this._updateApps);
-        dis.unregister(this.dispatcherRef);
+        if (this.dispatcherRef) dis.unregister(this.dispatcherRef);
     },
 
     componentWillReceiveProps(newProps) {

src/components/views/rooms/RoomRecoveryReminder.js

@@ -61,7 +61,6 @@ export default class RoomRecoveryReminder extends React.PureComponent {
                 loading: false,
                 error: e,
             });
-            return;
         }
     }
 

test/components/views/rooms/RoomSettings-test.js

@@ -134,7 +134,7 @@ describe.skip('RoomSettings', () => {
         });
     });
 
-    // XXX: Can't test this because we `getRoomDirectoryVisibility` in `componentWillMount`
+    // XXX: Can't test this because we `getRoomDirectoryVisibility` in `componentDidMount`
     xit('should set room directory publicity when set to true', (done) => {
         const isRoomPublished = true;
         roomSettings.setState({