Minor fixes based on lgtm.com alerts (#6819)

* Remove a couple of superfluous trailing arguments

* Simplify assignment logic in a couple of places

* Modify some potentially inconsistent setState calls to use the function form

* Fix eslint errors

webapp/components/admin_console/manage_teams_modal/manage_teams_dropdown.jsx

@@ -38,8 +38,8 @@ export default class ManageTeamsDropdown extends React.Component {
     }
 
     toggleDropdown() {
-        this.setState({
-            show: !this.state.show
+        this.setState((prevState) => {
+            return {show: !prevState.show};
         });
     }
 

webapp/components/admin_console/push_settings.jsx

@@ -79,8 +79,6 @@ export default class PushSettings extends AdminSettings {
             agree = true;
         } else if (config.EmailSettings.PushNotificationServer === Constants.MTPNS) {
             pushNotificationServerType = PUSH_NOTIFICATIONS_MTPNS;
-        } else {
-            pushNotificationServerType = PUSH_NOTIFICATIONS_CUSTOM;
         }
 
         let pushNotificationServer = config.EmailSettings.PushNotificationServer;

webapp/components/post_view/post_attachment.jsx

@@ -55,10 +55,11 @@ export default class PostAttachment extends React.PureComponent {
 
     toggleCollapseState(e) {
         e.preventDefault();
-
-        this.setState({
-            text: this.state.collapsed ? this.state.uncollapsedText : this.state.collapsedText,
-            collapsed: !this.state.collapsed
+        this.setState((prevState) => {
+            return {
+                text: prevState.collapsed ? prevState.uncollapsedText : prevState.collapsedText,
+                collapsed: !prevState.collapsed
+            };
         });
     }
 

webapp/components/post_view/post_body_additional_content.jsx

@@ -62,7 +62,9 @@ export default class PostBodyAdditionalContent extends React.PureComponent {
     }
 
     toggleEmbedVisibility() {
-        this.setState({embedVisible: !this.state.embedVisible});
+        this.setState((prevState) => {
+            return {embedVisible: !prevState.embedVisible};
+        });
     }
 
     getSlackAttachment() {

webapp/components/sidebar.jsx

@@ -309,14 +309,13 @@ export default class Sidebar extends React.Component {
                     curIndex = i;
                 }
             }
-            let nextChannel = allChannels[curIndex];
             let nextIndex = curIndex;
             if (e.keyCode === Constants.KeyCodes.DOWN) {
                 nextIndex = curIndex + 1;
             } else if (e.keyCode === Constants.KeyCodes.UP) {
                 nextIndex = curIndex - 1;
             }
-            nextChannel = allChannels[Utils.mod(nextIndex, allChannels.length)];
+            const nextChannel = allChannels[Utils.mod(nextIndex, allChannels.length)];
             ChannelActions.goToChannel(nextChannel);
             this.updateScrollbarOnChannelChange(nextChannel);
             this.isSwitchingChannel = false;
@@ -342,7 +341,6 @@ export default class Sidebar extends React.Component {
                     curIndex = i;
                 }
             }
-            let nextChannel = allChannels[curIndex];
             let nextIndex = curIndex;
             let count = 0;
             let increment = 0;
@@ -359,7 +357,7 @@ export default class Sidebar extends React.Component {
                 unreadCounts = ChannelStore.getUnreadCount(allChannels[nextIndex].id);
             }
             if (unreadCounts.msgs !== 0 || unreadCounts.mentions !== 0) {
-                nextChannel = allChannels[nextIndex];
+                const nextChannel = allChannels[nextIndex];
                 ChannelActions.goToChannel(nextChannel);
                 this.updateScrollbarOnChannelChange(nextChannel);
             }

webapp/components/textbox.jsx

@@ -157,7 +157,9 @@ export default class Textbox extends React.Component {
     showPreview(e) {
         e.preventDefault();
         e.target.blur();
-        this.setState({preview: !this.state.preview});
+        this.setState((prevState) => {
+            return {preview: prevState.preview};
+        });
     }
 
     hidePreview() {

webapp/components/webrtc/components/webrtc_sidebar.jsx

@@ -76,7 +76,9 @@ export default class SidebarRight extends React.Component {
         if (e) {
             e.preventDefault();
         }
-        this.setState({expanded: !this.state.expanded});
+        this.setState((prevState) => {
+            return {expanded: !prevState.expanded};
+        });
     }
 
     onInitializeVideoCall(userId, isCaller) {