Roll attribute selector

Closes #1771

PiperOrigin-RevId: 242039436

Author: MichaelRFairhurst

angular_analyzer_plugin/lib/src/selector/attribute_selector.dart

@@ -0,0 +1,42 @@
+import 'package:angular_analyzer_plugin/src/selector/attribute_selector_base.dart';
+import 'package:angular_analyzer_plugin/src/selector/element_view.dart';
+import 'package:angular_analyzer_plugin/src/selector/html_tag_for_selector.dart';
+import 'package:angular_analyzer_plugin/src/selector/selector.dart';
+import 'package:angular_analyzer_plugin/src/selector/match.dart';
+import 'package:angular_analyzer_plugin/src/selector/name.dart';
+
+/// The [Selector] that matches elements that have an attribute with the
+/// given name, and (optionally) with the given value;
+class AttributeSelector extends AttributeSelectorBase {
+  @override
+  final SelectorName nameElement;
+  final String value;
+
+  AttributeSelector(this.nameElement, this.value);
+
+  @override
+  List<SelectorName> getAttributes(ElementView element) =>
+      match(element, null) == SelectorMatch.NonTagMatch ? [] : [nameElement];
+
+  @override
+  bool matchValue(String attributeValue) =>
+      value == null || attributeValue == value;
+
+  @override
+  List<HtmlTagForSelector> refineTagSuggestions(
+      List<HtmlTagForSelector> context) {
+    for (final tag in context) {
+      tag.setAttribute(nameElement.string, value: value);
+    }
+    return context;
+  }
+
+  @override
+  String toString() {
+    final name = nameElement.string;
+    if (value != null) {
+      return '[$name=$value]';
+    }
+    return '[$name]';
+  }
+}