linter: Bump language version to 3.9

Change-Id: I4af051894d8aeabbb68ce086b740c212364adb75
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/447380
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: srawlins

pkg/linter/analysis_options.yaml

@@ -60,6 +60,7 @@ linter:
     - unreachable_from_main
     - use_if_null_to_convert_nulls_to_bools
     - use_late_for_private_fields_and_variables
+    - use_null_aware_elements
     - use_setters_to_change_properties
     - use_string_buffers
     - use_to_and_as_if_applicable

pkg/linter/lib/src/extensions.dart

@@ -377,10 +377,9 @@ extension ExpressionExtension on Expression {
     if (enclosingElement is! InterfaceElement) return false;
 
     var superTypes = enclosingElement.allSupertypes;
-    var superMembers =
-        element is MethodElement
-            ? superTypes.map((t) => t.getMethod(elementName))
-            : superTypes.map((t) => t.getGetter(elementName));
+    var superMembers = element is MethodElement
+        ? superTypes.map((t) => t.getMethod(elementName))
+        : superTypes.map((t) => t.getGetter(elementName));
     return superMembers.any((e) => e.hasAwaitNotRequired);
   }
 }

pkg/linter/lib/src/rules/always_put_control_body_on_new_line.dart

@@ -70,8 +70,9 @@ class _Visitor extends SimpleAstVisitor<void> {
     if (node == null || node is Block && node.statements.isEmpty) return;
 
     var unit = node.root as CompilationUnit;
-    var offsetFirstStatement =
-        node is Block ? node.statements.first.offset : node.offset;
+    var offsetFirstStatement = node is Block
+        ? node.statements.first.offset
+        : node.offset;
     var lineInfo = unit.lineInfo;
     if (lineInfo.getLocation(controlEnd).lineNumber ==
         lineInfo.getLocation(offsetFirstStatement).lineNumber) {

pkg/linter/lib/src/rules/analyzer_element_model_tracking.dart

@@ -61,11 +61,10 @@ class _Visitor extends SimpleAstVisitor<void> {
     var element = node.declaredFragment!.element;
     if (element.isElementClass) {
       for (var member in node.members) {
-        var trackingAnnotations =
-            member.metadata
-                .map((node) => node.asTrackingAnnotation)
-                .nonNulls
-                .toList();
+        var trackingAnnotations = member.metadata
+            .map((node) => node.asTrackingAnnotation)
+            .nonNulls
+            .toList();
 
         switch (member) {
           case ConstructorDeclaration():

pkg/linter/lib/src/rules/avoid_redundant_argument_values.dart

@@ -142,8 +142,10 @@ class _Visitor extends SimpleAstVisitor<void> {
         );
       } else {
         // Count which positional argument we're at.
-        var positionalCount =
-            arguments.take(i + 1).where((a) => a is! NamedExpression).length;
+        var positionalCount = arguments
+            .take(i + 1)
+            .where((a) => a is! NamedExpression)
+            .length;
         var positionalIndex = positionalCount - 1;
         if (positionalIndex < parameters.length) {
           if (parameters[positionalIndex].isPositional) {

pkg/linter/lib/src/rules/avoid_renaming_method_parameters.dart

@@ -85,8 +85,9 @@ class _Visitor extends SimpleAstVisitor<void> {
     } else {
       if (!node.isAugmentation) return;
 
-      parentParameters =
-          previousFragment.formalParameters.map((p) => p.element).positional;
+      parentParameters = previousFragment.formalParameters
+          .map((p) => p.element)
+          .positional;
     }
 
     var parameters = nodeParams.parameters.where((p) => !p.isNamed).toList();

pkg/linter/lib/src/rules/avoid_shadowing_type_parameters.dart

@@ -120,10 +120,9 @@ class _Visitor extends SimpleAstVisitor<void> {
       return;
     }
 
-    var ancestorTypeParameterNames =
-        ancestorTypeParameters.typeParameters
-            .map((tp) => tp.name.lexeme)
-            .toSet();
+    var ancestorTypeParameterNames = ancestorTypeParameters.typeParameters
+        .map((tp) => tp.name.lexeme)
+        .toSet();
 
     for (var parameter in typeParameters.typeParameters) {
       var lexeme = parameter.name.lexeme;

pkg/linter/lib/src/rules/avoid_type_to_string.dart

@@ -115,8 +115,9 @@ class _Visitor extends SimpleAstVisitor<void> {
   void _validateArgument(Expression expression) {
     if (expression is PropertyAccess) {
       var expressionType = expression.realTarget.staticType;
-      var targetType =
-          (expressionType is InterfaceType) ? expressionType : thisType;
+      var targetType = (expressionType is InterfaceType)
+          ? expressionType
+          : thisType;
       _reportIfToStringOnCoreTypeClass(targetType, expression.propertyName);
     } else if (expression is PrefixedIdentifier) {
       var prefixType = expression.prefix.staticType;

pkg/linter/lib/src/rules/avoid_unnecessary_containers.dart

@@ -46,8 +46,8 @@ class _Visitor extends SimpleAstVisitor<void> {
     if (parent is NamedExpression && parent.name.label.name == 'child') {
       var args = parent.thisOrAncestorOfType<ArgumentList>();
       if (args?.arguments.length == 1) {
-        var parentCreation =
-            parent.thisOrAncestorOfType<InstanceCreationExpression>();
+        var parentCreation = parent
+            .thisOrAncestorOfType<InstanceCreationExpression>();
         if (parentCreation != null) {
           if (isExactWidgetTypeContainer(parentCreation.staticType)) {
             rule.reportAtNode(parentCreation.constructorName);

pkg/linter/lib/src/rules/avoid_unused_constructor_parameters.dart

@@ -41,15 +41,14 @@ class _ConstructorVisitor extends RecursiveAstVisitor<void> {
   final Set<FormalParameter> unusedParameters;
 
   _ConstructorVisitor(this.element)
-    : unusedParameters =
-          element.parameters.parameters.where((p) {
-            var element = p.declaredFragment?.element;
-            return element != null &&
-                element is! FieldFormalParameterElement &&
-                element is! SuperFormalParameterElement &&
-                !element.metadata.hasDeprecated &&
-                !(element.name ?? '').isJustUnderscores;
-          }).toSet();
+    : unusedParameters = element.parameters.parameters.where((p) {
+        var element = p.declaredFragment?.element;
+        return element != null &&
+            element is! FieldFormalParameterElement &&
+            element is! SuperFormalParameterElement &&
+            !element.metadata.hasDeprecated &&
+            !(element.name ?? '').isJustUnderscores;
+      }).toSet();
 
   @override
   void visitSimpleIdentifier(SimpleIdentifier node) {