Fix lint errors in TimelinePanel

.eslintignore.errorfiles

@@ -10,7 +10,6 @@ src/components/structures/RoomStatusBar.js
 src/components/structures/RoomView.js
 src/components/structures/ScrollPanel.js
 src/components/structures/SearchBox.js
-src/components/structures/TimelinePanel.js
 src/components/structures/UploadBar.js
 src/components/views/avatars/BaseAvatar.js
 src/components/views/avatars/MemberAvatar.js

src/components/structures/TimelinePanel.js

@@ -44,11 +44,10 @@ const READ_RECEIPT_INTERVAL_MS = 500;
 
 const DEBUG = false;
 
+let debuglog = function() {};
 if (DEBUG) {
     // using bind means that we get to keep useful line numbers in the console
-    var debuglog = console.log.bind(console);
+    debuglog = console.log.bind(console);
-} else {
-    var debuglog = function() {};
 }
 
 /*
@@ -56,7 +55,7 @@ if (DEBUG) {
  *
  * Also responsible for handling and sending read receipts.
  */
-var TimelinePanel = React.createClass({
+const TimelinePanel = React.createClass({
     displayName: 'TimelinePanel',
 
     propTypes: {
@@ -445,6 +444,7 @@ var TimelinePanel = React.createClass({
 
             const updatedState = {events: events};
 
+            let callRMUpdated;
             if (this.props.manageReadMarkers) {
                 // when a new event arrives when the user is not watching the
                 // window, but the window is in its auto-scroll mode, make sure the
@@ -456,7 +456,7 @@ var TimelinePanel = React.createClass({
                 //
                 const myUserId = MatrixClientPeg.get().credentials.userId;
                 const sender = ev.sender ? ev.sender.userId : null;
-                var callRMUpdated = false;
+                callRMUpdated = false;
                 if (sender != myUserId && !UserActivity.sharedInstance().userActiveRecently()) {
                     updatedState.readMarkerVisible = true;
                 } else if (lastEv && this.getReadMarkerPosition() === 0) {
@@ -566,7 +566,7 @@ var TimelinePanel = React.createClass({
             UserActivity.sharedInstance().timeWhileActiveRecently(this._readMarkerActivityTimer);
             try {
                 await this._readMarkerActivityTimer.finished();
-            } catch(e) { continue; /* aborted */ }
+            } catch (e) { continue; /* aborted */ }
             // outside of try/catch to not swallow errors
             this.updateReadMarker();
         }
@@ -578,7 +578,7 @@ var TimelinePanel = React.createClass({
             UserActivity.sharedInstance().timeWhileActiveNow(this._readReceiptActivityTimer);
             try {
                 await this._readReceiptActivityTimer.finished();
-            } catch(e) { continue; /* aborted */ }
+            } catch (e) { continue; /* aborted */ }
             // outside of try/catch to not swallow errors
             this.sendReadReceipt();
         }
@@ -732,7 +732,8 @@ var TimelinePanel = React.createClass({
         const events = this._timelineWindow.getEvents();
 
         // first find where the current RM is
-        for (var i = 0; i < events.length; i++) {
+        let i;
+        for (i = 0; i < events.length; i++) {
             if (events[i].getId() == this.state.readMarkerEventId) {
                 break;
             }
@@ -744,7 +745,7 @@ var TimelinePanel = React.createClass({
         // now think about advancing it
         const myUserId = MatrixClientPeg.get().credentials.userId;
         for (i++; i < events.length; i++) {
-            var ev = events[i];
+            const ev = events[i];
             if (!ev.sender || ev.sender.userId != myUserId) {
                 break;
             }
@@ -752,7 +753,7 @@ var TimelinePanel = React.createClass({
         // i is now the first unread message which we didn't send ourselves.
         i--;
 
-        var ev = events[i];
+        const ev = events[i];
         this._setReadMarker(ev.getId(), ev.getTs());
     },
 
@@ -882,7 +883,7 @@ var TimelinePanel = React.createClass({
         return ret;
     },
 
-    /**
+    /*
      * called by the parent component when PageUp/Down/etc is pressed.
      *
      * We pass it down to the scroll panel.
@@ -975,11 +976,10 @@ var TimelinePanel = React.createClass({
         };
 
         const onError = (error) => {
-            this.setState({timelineLoading: false});
+            this.setState({ timelineLoading: false });
             console.error(
                 `Error loading timeline panel at ${eventId}: ${error}`,
             );
-            const msg = error.message ? error.message : JSON.stringify(error);
             const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
 
             let onFinished;
@@ -997,9 +997,18 @@ var TimelinePanel = React.createClass({
                     });
                 };
             }
-            const message = (error.errcode == 'M_FORBIDDEN')
+            let message;
-            	? _t("Tried to load a specific point in this room's timeline, but you do not have permission to view the message in question.")
+            if (error.errcode == 'M_FORBIDDEN') {
-                : _t("Tried to load a specific point in this room's timeline, but was unable to find it.");
+                message = _t(
+                    "Tried to load a specific point in this room's timeline, but you " +
+                    "do not have permission to view the message in question.",
+                );
+            } else {
+                message = _t(
+                    "Tried to load a specific point in this room's timeline, but was " +
+                    "unable to find it.",
+                );
+            }
             Modal.createTrackedDialog('Failed to load timeline position', '', ErrorDialog, {
                 title: _t("Failed to load timeline position"),
                 description: message,
@@ -1104,12 +1113,13 @@ var TimelinePanel = React.createClass({
     },
 
     /**
-     * get the id of the event corresponding to our user's latest read-receipt.
+     * Get the id of the event corresponding to our user's latest read-receipt.
      *
      * @param {Boolean} ignoreSynthesized If true, return only receipts that
      *                                    have been sent by the server, not
      *                                    implicit ones generated by the JS
      *                                    SDK.
+     * @return {String} the event ID
      */
     _getCurrentReadReceipt: function(ignoreSynthesized) {
         const client = MatrixClientPeg.get();