Avoid a few non-null assertions

Author: parlough

dwds/debug_extension/web/background.dart

@@ -45,8 +45,8 @@ void _registerListeners() {
   chrome.windows.onFocusChanged.addListener(
     allowInterop((_) async {
       final currentTab = await activeTab;
-      if (currentTab?.id != null) {
-        await _updateIcon(currentTab!.id);
+      if (currentTab?.id case final tabId?) {
+        await _updateIcon(tabId);
       }
     }),
   );

dwds/debug_extension/web/debug_session.dart

@@ -349,11 +349,12 @@ Future<bool> _connectToDwds({
   required int dartAppTabId,
   required DebugInfo debugInfo,
 }) async {
-  if (debugInfo.extensionUrl == null) {
+  final extensionUrl = debugInfo.extensionUrl;
+  if (extensionUrl == null) {
     debugWarn('Can\'t connect to DWDS without an extension URL.');
     return false;
   }
-  final uri = Uri.parse(debugInfo.extensionUrl!);
+  final uri = Uri.parse(extensionUrl);
   // Start the client connection with DWDS:
   final client = uri.isScheme('ws') || uri.isScheme('wss')
       ? WebSocketClient(WebSocketChannel.connect(uri))

dwds/debug_extension/web/popup.dart

@@ -131,10 +131,11 @@ Future<void> _launchDevTools(Event _) async {
 }
 
 void _copyAppId(Event _) {
-  if (_appId == null) return;
+  final appId = _appId;
+  if (appId == null) return;
   final clipboard = window.navigator.clipboard;
   if (clipboard == null) return;
-  clipboard.writeText(_appId!);
+  clipboard.writeText(appId);
   _updateElementVisibility(_copiedSuccessId, visible: true);
 }
 

dwds/debug_extension/web/utils.dart

@@ -115,32 +115,18 @@ void setExtensionPopup(PopupDetails details) {
   }
 }
 
-bool? _isDevMode;
-
-bool get isDevMode {
-  if (_isDevMode != null) {
-    return _isDevMode!;
-  }
+final bool isDevMode = () {
   final extensionManifest = chrome.runtime.getManifest();
   final extensionName = getProperty<String?>(extensionManifest, 'name') ?? '';
-  final isDevMode = extensionName.contains('DEV');
-  _isDevMode = isDevMode;
-  return isDevMode;
-}
+  return extensionName.contains('DEV');
+}();
 
-bool? _isMV3;
-
-bool get isMV3 {
-  if (_isMV3 != null) {
-    return _isMV3!;
-  }
+final bool isMV3 = () {
   final extensionManifest = chrome.runtime.getManifest();
   final manifestVersion =
       getProperty(extensionManifest, 'manifest_version') ?? 2;
-  final isMV3 = manifestVersion == 3;
-  _isMV3 = isMV3;
-  return isMV3;
-}
+  return manifestVersion == 3;
+}();
 
 String addQueryParameters(
   String uri, {