refactor: more lint improvements

- set parserOptions.ecmaVersion to latest and env to es2024 in eslint config
- install missing types libraries
- install eslint-plugin-sonar
- enable eslint-plugin-sonar recommended rules and declare jsx-runtime for react in eslint config
- clean up disabled lint rules which don't inflict problems anymore
- disable various lint issues and fix others

3 files changed, 6 insertions, 5 deletions

diff --git a/src/features/appearance/index.ts b/src/features/appearance/index.ts
index da75bf57b..46403275e 100644
--- a/src/features/appearance/index.ts
+++ b/src/features/appearance/index.ts
@@ -146,12 +146,13 @@ function generateServiceRibbonWidthStyle(
 ) {
   const width = Number(widthStr);
   const iconSize = Number(iconSizeStr) - iconSizeBias;
-  let fontSize = 11;
-  let tabItemHeightBias = -5;
-  let sidebarSizeBias = 22;
   const tabItemWidthBias = 3;
   const verticalStyleOffset = 29;
 
+  let fontSize: number;
+  let tabItemHeightBias: number;
+  let sidebarSizeBias: number;
+
   switch (width) {
     case 35: {
       fontSize = 9;
diff --git a/src/features/workspaces/components/WorkspacesDashboard.tsx b/src/features/workspaces/components/WorkspacesDashboard.tsx
index a823132c5..ba06730a0 100644
--- a/src/features/workspaces/components/WorkspacesDashboard.tsx
+++ b/src/features/workspaces/components/WorkspacesDashboard.tsx
@@ -152,6 +152,7 @@ class WorkspacesDashboard extends Component<IProps> {
                   {intl.formatMessage(messages.workspacesRequestFailed)}
                 </Infobox>
               ) : (
+                // eslint-disable-next-line react/jsx-no-useless-fragment
                 <>
                   {workspaces.length === 0 ? (
                     <div className="align-middle settings__empty-state">
diff --git a/src/features/workspaces/containers/EditWorkspaceScreen.tsx b/src/features/workspaces/containers/EditWorkspaceScreen.tsx
index 0b66db0d0..abc747c33 100644
--- a/src/features/workspaces/containers/EditWorkspaceScreen.tsx
+++ b/src/features/workspaces/containers/EditWorkspaceScreen.tsx
@@ -9,11 +9,10 @@ import { workspaceStore } from '../index';
 import { deleteWorkspaceRequest, updateWorkspaceRequest } from '../api';
 
 class EditWorkspaceScreen extends Component<StoresProps> {
-  // @ts-expect-error Not all code paths return a value.
   onDelete = () => {
     const { workspaceBeingEdited } = workspaceStore;
     const { actions } = this.props;
-    if (!workspaceBeingEdited) return null;
+    if (!workspaceBeingEdited) return;
     actions.workspaces.delete({ workspace: workspaceBeingEdited });
   };