Enhancement/custom uni UI lint

.gitignore

@@ -19,3 +19,6 @@ packages/uni_ui/pubspec.lock
 # Key properties
 uni/android/key.properties
 **.jks
+
+# Custom Lint log
+custom_lint.log

packages/uni_lint/README.md

@@ -0,0 +1,7 @@
+# uni_lint
+
+This package contains custom lint rules for uni development. 
+
+Try to keep dependencies to the minimum. This package, ideally,
+should not have any dependencies, except for the analyzer package
+and custom_lint_builder.

packages/uni_lint/lib/uni_lint.dart

@@ -0,0 +1,59 @@
+import 'package:analyzer/error/listener.dart';
+import 'package:custom_lint_builder/custom_lint_builder.dart';
+import 'package:analyzer/dart/ast/ast.dart';
+
+PluginBase createPlugin() => _ExampleLinter();
+
+class _ExampleLinter extends PluginBase {
+  @override
+  List<LintRule> getLintRules(CustomLintConfigs configs) => [
+        StringLiteralsLint(),
+      ];
+}
+
+class StringLiteralsLint extends DartLintRule {
+  StringLiteralsLint() : super(code: _code);
+
+  static const _code = LintCode(
+    name: 'string_literals_lint',
+    problemMessage: 'There is a string literal inside a widget',
+  );
+
+  @override
+  void run(
+    CustomLintResolver resolver,
+    ErrorReporter reporter,
+    CustomLintContext context,
+  ) {
+    context.registry.addVariableDeclaration((node) {
+      if (isInsideWidgetClass(node)) {
+        if (isStringLiteral(node)) {
+          reporter.atNode(node, code);
+        }
+      }
+    });
+  }
+
+  bool isInsideWidgetClass(VariableDeclaration node) {
+    var parent = node.thisOrAncestorOfType<ClassDeclaration>();
+    if (parent == null) return false;
+
+    final extendsClause = parent.extendsClause;
+    if (extendsClause != null) {
+      final superclass = extendsClause.superclass;
+      print(superclass.element?.displayName == "StatelessWidget");
+      return true;
+      // return superclass.runtimeType == StatelessWidget ||
+      //     superclass.runtimeType == StatefulWidget;
+    }
+    return false;
+  }
+
+  bool isStringLiteral(VariableDeclaration node) {
+    final initializer = node.initializer;
+    if (initializer is StringLiteral) {
+      return true;
+    }
+    return false;
+  }
+}