Move more of KeywordContributor to the new framework

Change-Id: I2b257545a3af7fa2f803e8f954d14cd3679c35c1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/319781
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/services/completion/dart/in_scope_completion_pass.dart

@@ -102,6 +102,11 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
     _forExpression(node);
   }
 
+  @override
+  void visitBooleanLiteral(BooleanLiteral node) {
+    _forExpression(node);
+  }
+
   @override
   void visitClassDeclaration(ClassDeclaration node) {
     if (offset < node.classKeyword.offset) {
@@ -141,11 +146,99 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
     }
   }
 
+  @override
+  void visitConstructorDeclaration(ConstructorDeclaration node) {
+    var separator = node.separator;
+    if (separator != null) {
+      if (offset >= separator.end && offset <= node.body.offset) {
+        collector.completionLocation = 'ConstructorDeclaration_initializer';
+        keywordHelper.addConstructorInitializerKeywords(node);
+      }
+    }
+  }
+
   @override
   void visitDoubleLiteral(DoubleLiteral node) {
     _visitParentIfAtOrBeforeNode(node);
   }
 
+  @override
+  void visitEnumDeclaration(EnumDeclaration node) {
+    if (!featureSet.isEnabled(Feature.enhanced_enums)) {
+      return;
+    }
+    if (offset < node.enumKeyword.offset) {
+      // There are no modifiers for enums.
+      return;
+    }
+    if (offset <= node.enumKeyword.end) {
+      keywordHelper.addKeyword(Keyword.ENUM);
+      return;
+    }
+    if (offset <= node.name.end) {
+      // TODO(brianwilkerson) Suggest a name for the mixin.
+      return;
+    }
+    if (offset <= node.leftBracket.offset) {
+      keywordHelper.addEnumDeclarationKeywords(node);
+      return;
+    }
+    var rightBracket = node.rightBracket;
+    if (!rightBracket.isSynthetic && offset >= rightBracket.end) {
+      return;
+    }
+    var semicolon = node.semicolon;
+    if (semicolon != null && offset >= semicolon.end) {
+      collector.completionLocation = 'EnumDeclaration_member';
+      _forEnumMember();
+    }
+  }
+
+  @override
+  void visitExtensionDeclaration(ExtensionDeclaration node) {
+    if (offset < node.extensionKeyword.offset) {
+      // There are no modifiers for extensions.
+      return;
+    }
+    if (offset <= node.extensionKeyword.end) {
+      keywordHelper.addKeyword(Keyword.EXTENSION);
+      return;
+    }
+    var name = node.name;
+    if (name != null && offset <= name.end) {
+      // TODO(brianwilkerson) We probably need to suggest `on`.
+      // TODO(brianwilkerson) We probably need to suggest `type` when extension
+      //  types are supported.
+      // Don't suggest a name for the extension.
+      return;
+    }
+    if (offset <= node.leftBracket.offset) {
+      if (node.onKeyword.isSynthetic) {
+        keywordHelper.addExtensionDeclarationKeywords(node);
+      } else {
+        collector.completionLocation = 'ExtensionDeclaration_extendedType';
+      }
+      return;
+    }
+    if (offset >= node.leftBracket.end && offset <= node.rightBracket.offset) {
+      collector.completionLocation = 'ExtensionDeclaration_member';
+      _forExtensionMember();
+    }
+  }
+
+  @override
+  void visitFunctionDeclaration(FunctionDeclaration node) {
+    // If the cursor is at the beginning of the declaration, include the
+    // compilation unit keywords. See dartbug.com/41039.
+    var returnType = node.returnType;
+    if ((returnType == null || returnType.beginToken == returnType.endToken) &&
+        offset <= node.name.offset) {
+      collector.completionLocation = 'FunctionDeclaration_returnType';
+      keywordHelper.addKeyword(Keyword.DYNAMIC);
+      keywordHelper.addKeyword(Keyword.VOID);
+    }
+  }
+
   @override
   void visitIntegerLiteral(IntegerLiteral node) {
     _visitParentIfAtOrBeforeNode(node);
@@ -204,6 +297,42 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
     _forPattern();
   }
 
+  @override
+  void visitMixinDeclaration(MixinDeclaration node) {
+    if (offset < node.mixinKeyword.offset) {
+      keywordHelper.addMixinModifiers(node);
+      return;
+    }
+    if (offset <= node.mixinKeyword.end) {
+      keywordHelper.addKeyword(Keyword.MIXIN);
+      return;
+    }
+    if (offset <= node.name.end) {
+      // TODO(brianwilkerson) Suggest a name for the mixin.
+      return;
+    }
+    if (offset <= node.leftBracket.offset) {
+      keywordHelper.addMixinDeclarationKeywords(node);
+      return;
+    }
+    if (offset >= node.leftBracket.end && offset <= node.rightBracket.offset) {
+      collector.completionLocation = 'MixinDeclaration_member';
+      _forMixinMember();
+      var element = node.members.elementBefore(offset);
+      if (element is MethodDeclaration) {
+        var body = element.body;
+        if (body.isEmpty) {
+          keywordHelper.addFunctionBodyModifiers(body);
+        }
+      }
+    }
+  }
+
+  @override
+  void visitNullLiteral(NullLiteral node) {
+    _forExpression(node);
+  }
+
   @override
   void visitParenthesizedPattern(ParenthesizedPattern node) {
     collector.completionLocation = 'ParenthesizedPattern_expression';
@@ -274,6 +403,53 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
     _visitParentIfAtOrBeforeNode(node);
   }
 
+  @override
+  void visitSymbolLiteral(SymbolLiteral node) {
+    _forExpression(node);
+  }
+
+  @override
+  void visitThisExpression(ThisExpression node) {
+    _forExpression(node);
+  }
+
+  @override
+  void visitThrowExpression(ThrowExpression node) {
+    collector.completionLocation = 'ThrowExpression_expression';
+    _forExpression(node);
+  }
+
+  @override
+  void visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
+    var variableDeclarationList = node.variables;
+    var variables = variableDeclarationList.variables;
+    if (variables.isEmpty || offset > variables.first.beginToken.end) {
+      return;
+    }
+    if (node.externalKeyword == null) {
+      keywordHelper.addKeyword(Keyword.EXTERNAL);
+    }
+    if (variableDeclarationList.lateKeyword == null &&
+        featureSet.isEnabled(Feature.non_nullable)) {
+      keywordHelper.addKeyword(Keyword.LATE);
+    }
+    if (!variables.first.isConst) {
+      keywordHelper.addKeyword(Keyword.CONST);
+    }
+    if (!variables.first.isFinal) {
+      keywordHelper.addKeyword(Keyword.FINAL);
+    }
+  }
+
+  @override
+  void visitVariableDeclaration(VariableDeclaration node) {
+    var equals = node.equals;
+    if (equals != null && offset >= equals.end) {
+      collector.completionLocation = 'VariableDeclaration_initializer';
+      _forExpression(node);
+    }
+  }
+
   /// Add the suggestions that are appropriate when the selection is at the
   /// beginning of a class member.
   void _forClassMember() {
@@ -304,6 +480,12 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
     // _addVariablesInScope(node, mustBeConstant: true);
   }
 
+  /// Add the suggestions that are appropriate when the selection is at the
+  /// beginning of an enum member.
+  void _forEnumMember() {
+    keywordHelper.addEnumMemberKeywords();
+  }
+
   /// Add the suggestions that are appropriate when the selection is at the
   /// beginning of an expression. The [node] provides context to determine which
   /// keywords to include.
@@ -314,6 +496,18 @@ class InScopeCompletionPass extends SimpleAstVisitor<void> {
     // _addVariablesInScope(node);
   }
 
+  /// Add the suggestions that are appropriate when the selection is at the
+  /// beginning of an extension member.
+  void _forExtensionMember() {
+    keywordHelper.addExtensionMemberKeywords();
+  }
+
+  /// Add the suggestions that are appropriate when the selection is at the
+  /// beginning of a mixin member.
+  void _forMixinMember() {
+    keywordHelper.addMixinMemberKeywords();
+  }
+
   /// Add the suggestions that are appropriate when the selection is at the
   /// beginning of a pattern.
   void _forPattern() {

pkg/analysis_server/lib/src/services/completion/dart/keyword_contributor.dart

@@ -170,11 +170,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  @override
-  void visitBooleanLiteral(BooleanLiteral node) {
-    _addExpressionKeywords(node);
-  }
-
   @override
   void visitCascadeExpression(CascadeExpression node) {
     _addExpressionKeywords(node);
@@ -251,33 +246,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     _addExpressionKeywords(node);
   }
 
-  @override
-  void visitConstructorDeclaration(ConstructorDeclaration node) {
-    if (node.initializers.isNotEmpty) {
-      if (entity is ConstructorInitializer) {
-        _addSuggestion(Keyword.ASSERT);
-      }
-      var last = node.initializers.last;
-      if (last == entity) {
-        var previous = node.findPrevious(last.beginToken);
-        if (previous != null && previous.end <= request.offset) {
-          _addSuggestion(Keyword.SUPER);
-          _addSuggestion(Keyword.THIS);
-        }
-      }
-    } else {
-      var separator = node.separator;
-      if (separator != null) {
-        var offset = request.offset;
-        if (separator.end <= offset && offset <= separator.next!.offset) {
-          _addSuggestion(Keyword.ASSERT);
-          _addSuggestion(Keyword.SUPER);
-          _addSuggestion(Keyword.THIS);
-        }
-      }
-    }
-  }
-
   @override
   void visitConstructorReference(ConstructorReference node) {
     _addExpressionKeywords(node);
@@ -301,29 +269,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  @override
-  void visitEnumDeclaration(EnumDeclaration node) {
-    if (!request.featureSet.isEnabled(Feature.enhanced_enums)) {
-      return;
-    }
-
-    if (entity == node.name) {
-      return;
-    }
-
-    var semicolon = node.semicolon;
-    if (request.offset <= node.leftBracket.offset) {
-      if (node.withClause == null) {
-        _addSuggestion(Keyword.WITH);
-      }
-      if (node.implementsClause == null) {
-        _addSuggestion(Keyword.IMPLEMENTS);
-      }
-    } else if (semicolon != null && semicolon.end <= request.offset) {
-      _addEnumBodyKeywords();
-    }
-  }
-
   @override
   void visitExpressionFunctionBody(ExpressionFunctionBody node) {
     if (entity == node.expression) {
@@ -331,21 +276,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  @override
-  void visitExtensionDeclaration(ExtensionDeclaration node) {
-    // Don't suggest extension name
-    if (entity == node.name) {
-      return;
-    }
-    if (entity == node.rightBracket) {
-      _addExtensionBodyKeywords();
-    } else if (entity is ClassMember) {
-      _addExtensionBodyKeywords();
-    } else {
-      _addExtensionDeclarationKeywords(node);
-    }
-  }
-
   @override
   void visitExtensionOverride(ExtensionOverride node) {
     _addExpressionKeywords(node);
@@ -546,16 +476,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  @override
-  void visitFunctionDeclaration(FunctionDeclaration node) {
-    // If the cursor is at the beginning of the declaration, include the
-    // compilation unit keywords.  See dartbug.com/41039.
-    if (entity == node.returnType || entity == node.name) {
-      _addSuggestion(Keyword.DYNAMIC);
-      _addSuggestion(Keyword.VOID);
-    }
-  }
-
   @override
   void visitFunctionExpression(FunctionExpression node) {
     if (entity == node.body) {
@@ -724,29 +644,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  @override
-  void visitMixinDeclaration(MixinDeclaration node) {
-    final entity = this.entity;
-    // Don't suggest mixin name
-    if (entity == node.name) {
-      return;
-    }
-    if (entity == node.rightBracket) {
-      _addClassBodyKeywords();
-    } else if (entity is ClassMember) {
-      _addClassBodyKeywords();
-      var index = node.members.indexOf(entity);
-      var previous = index > 0 ? node.members[index - 1] : null;
-      if (previous is MethodDeclaration && previous.body.isEmpty) {
-        _addSuggestion(Keyword.ASYNC);
-        _addSuggestion2(ASYNC_STAR);
-        _addSuggestion2(SYNC_STAR);
-      }
-    } else if (entity != node.mixinKeyword) {
-      _addMixinDeclarationKeywords(node);
-    }
-  }
-
   @override
   void visitNamedExpression(NamedExpression node) {
     if (entity is SimpleIdentifier && entity == node.expression) {
@@ -754,11 +651,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  @override
-  void visitNullLiteral(NullLiteral node) {
-    _addExpressionKeywords(node);
-  }
-
   @override
   void visitParenthesizedExpression(ParenthesizedExpression node) {
     var expression = node.expression;
@@ -913,44 +805,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  @override
-  void visitSymbolLiteral(SymbolLiteral node) {
-    _addExpressionKeywords(node);
-  }
-
-  @override
-  void visitThisExpression(ThisExpression node) {
-    _addExpressionKeywords(node);
-  }
-
-  @override
-  void visitThrowExpression(ThrowExpression node) {
-    _addExpressionKeywords(node);
-  }
-
-  @override
-  void visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
-    var variableDeclarationList = node.variables;
-    if (entity != variableDeclarationList) return;
-    var variables = variableDeclarationList.variables;
-    if (variables.isEmpty || request.offset > variables.first.beginToken.end) {
-      return;
-    }
-    if (node.externalKeyword == null) {
-      _addSuggestion(Keyword.EXTERNAL);
-    }
-    if (variableDeclarationList.lateKeyword == null &&
-        request.featureSet.isEnabled(Feature.non_nullable)) {
-      _addSuggestion(Keyword.LATE);
-    }
-    if (!variables.first.isConst) {
-      _addSuggestion(Keyword.CONST);
-    }
-    if (!variables.first.isFinal) {
-      _addSuggestion(Keyword.FINAL);
-    }
-  }
-
   @override
   void visitTryStatement(TryStatement node) {
     var obj = entity;
@@ -973,13 +827,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     _addExpressionKeywords(node);
   }
 
-  @override
-  void visitVariableDeclaration(VariableDeclaration node) {
-    if (entity == node.initializer) {
-      _addExpressionKeywords(node);
-    }
-  }
-
   @override
   void visitVariableDeclarationList(VariableDeclarationList node) {
     var keyword = node.keyword;
@@ -1086,21 +933,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  void _addEnumBodyKeywords() {
-    _addSuggestions([
-      Keyword.CONST,
-      Keyword.DYNAMIC,
-      Keyword.FINAL,
-      Keyword.GET,
-      Keyword.LATE,
-      Keyword.OPERATOR,
-      Keyword.SET,
-      Keyword.STATIC,
-      Keyword.VAR,
-      Keyword.VOID
-    ]);
-  }
-
   void _addExpressionKeywords(AstNode node) {
     _addSuggestions([
       Keyword.FALSE,
@@ -1121,23 +953,6 @@ class _KeywordVisitor extends SimpleAstVisitor<void> {
     }
   }
 
-  void _addExtensionBodyKeywords() {
-    _addSuggestions([
-      Keyword.CONST,
-      Keyword.DYNAMIC,
-      Keyword.FINAL,
-      Keyword.GET,
-      Keyword.OPERATOR,
-      Keyword.SET,
-      Keyword.STATIC,
-      Keyword.VAR,
-      Keyword.VOID
-    ]);
-    if (request.featureSet.isEnabled(Feature.non_nullable)) {
-      _addSuggestion(Keyword.LATE);
-    }
-  }
-
   void _addExtensionDeclarationKeywords(ExtensionDeclaration node) {
     if (node.onKeyword.isSynthetic) {
       _addSuggestion(Keyword.ON);

pkg/analysis_server/lib/src/services/completion/dart/keyword_helper.dart

@@ -164,6 +164,32 @@ class KeywordHelper {
     }
   }
 
+  /// Add the keywords that are appropriate when the selection is in the
+  /// initializer list of the given [node].
+  void addConstructorInitializerKeywords(ConstructorDeclaration node) {
+    addKeyword(Keyword.ASSERT);
+    var suggestSuper = node.parent is! ExtensionTypeDeclaration;
+    var initializers = node.initializers;
+    if (initializers.isNotEmpty) {
+      var last = initializers.lastNonSynthetic;
+      if (offset >= last.end &&
+          last is! SuperConstructorInvocation &&
+          last is! RedirectingConstructorInvocation) {
+        if (suggestSuper) {
+          addKeyword(Keyword.SUPER);
+        }
+        addKeyword(Keyword.THIS);
+      }
+    } else {
+      // if (separator.end <= offset && offset <= separator.next!.offset) {
+      if (suggestSuper) {
+        addKeyword(Keyword.SUPER);
+      }
+      addKeyword(Keyword.THIS);
+      // }
+    }
+  }
+
   /// Add the keywords that are appropriate when the selection is in an enum
   /// declaration between the name of the enum and the body. The [node] is the
   /// enum declaration containing the selection point.
@@ -204,7 +230,12 @@ class KeywordHelper {
       if (node is CollectionElement && node is! Expression) {
         node = node.parent;
       }
-      return node is Expression && !node.inConstantContext;
+      if (node is Expression) {
+        return !node.inConstantContext;
+      } else if (node is VariableDeclaration) {
+        return !node.isConst;
+      }
+      return false;
     }
 
     addKeyword(Keyword.FALSE);
@@ -428,3 +459,13 @@ extension on CollectionElement? {
     return finalElement is IfElement && finalElement.elseKeyword == null;
   }
 }
+
+extension on NodeList<ConstructorInitializer> {
+  ConstructorInitializer get lastNonSynthetic {
+    final last = this.last;
+    if (last.beginToken.isSynthetic && length > 1) {
+      return this[length - 2];
+    }
+    return last;
+  }
+}

pkg/analysis_server/test/services/completion/dart/location/class_body_test.dart

@@ -254,8 +254,7 @@ suggestions
           Keyword.CONST,
           if (context.isClass || context.isMixin) Keyword.COVARIANT,
           Keyword.DYNAMIC,
-          // TODO(scheglov) This does not look right, mixin.
-          if (context.isClass || context.isMixin) Keyword.FACTORY,
+          if (context.isClass) Keyword.FACTORY,
           Keyword.FINAL,
           Keyword.GET,
           Keyword.LATE,
@@ -499,8 +498,7 @@ ${keywords.asKeywordSuggestions}
             Keyword.CONST,
             if (context.isClass || context.isMixin) Keyword.COVARIANT,
             Keyword.DYNAMIC,
-            // TODO(scheglov) This does not look right, mixin.
-            if (context.isClass || context.isMixin) Keyword.FACTORY,
+            if (context.isClass) Keyword.FACTORY,
             Keyword.FINAL,
             Keyword.GET,
             Keyword.LATE,