Merge pull request #3516 from Microsoft/extendsExpressions

Allow expressions in class extends clauses

Author: ahejlsberg

src/compiler/checker.ts

@@ -384,6 +384,11 @@ namespace ts {
         Cannot_find_namespace_0: { code: 2503, category: DiagnosticCategory.Error, key: "Cannot find namespace '{0}'." },
         No_best_common_type_exists_among_yield_expressions: { code: 2504, category: DiagnosticCategory.Error, key: "No best common type exists among yield expressions." },
         A_generator_cannot_have_a_void_type_annotation: { code: 2505, category: DiagnosticCategory.Error, key: "A generator cannot have a 'void' type annotation." },
+        _0_is_referenced_directly_or_indirectly_in_its_own_base_expression: { code: 2506, category: DiagnosticCategory.Error, key: "'{0}' is referenced directly or indirectly in its own base expression." },
+        Type_0_is_not_a_constructor_function_type: { code: 2507, category: DiagnosticCategory.Error, key: "Type '{0}' is not a constructor function type." },
+        No_base_constructor_has_the_specified_number_of_type_arguments: { code: 2508, category: DiagnosticCategory.Error, key: "No base constructor has the specified number of type arguments." },
+        Base_constructor_return_type_0_is_not_a_class_or_interface_type: { code: 2509, category: DiagnosticCategory.Error, key: "Base constructor return type '{0}' is not a class or interface type." },
+        Base_constructors_must_all_have_the_same_return_type: { code: 2510, category: DiagnosticCategory.Error, key: "Base constructors must all have the same return type." },
         Import_declaration_0_is_using_private_name_1: { code: 4000, category: DiagnosticCategory.Error, key: "Import declaration '{0}' is using private name '{1}'." },
         Type_parameter_0_of_exported_class_has_or_is_using_private_name_1: { code: 4002, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported class has or is using private name '{1}'." },
         Type_parameter_0_of_exported_interface_has_or_is_using_private_name_1: { code: 4004, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported interface has or is using private name '{1}'." },

src/compiler/diagnosticInformationMap.generated.ts

@@ -1525,6 +1525,26 @@
         "category": "Error",
         "code": 2505
     },
+    "'{0}' is referenced directly or indirectly in its own base expression.": {
+        "category": "Error",
+        "code": 2506
+    },
+    "Type '{0}' is not a constructor function type.": {
+        "category": "Error",
+        "code": 2507
+    },
+    "No base constructor has the specified number of type arguments.": {
+        "category": "Error",
+        "code": 2508
+    },
+    "Base constructor return type '{0}' is not a class or interface type.": {
+        "category": "Error",
+        "code": 2509
+    },
+    "Base constructors must all have the same return type.": {
+        "category": "Error",
+        "code": 2510
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

src/compiler/diagnosticMessages.json

@@ -1669,10 +1669,8 @@ namespace ts {
         typeParameters: TypeParameter[];           // Type parameters (undefined if non-generic)
         outerTypeParameters: TypeParameter[];      // Outer type parameters (undefined if none)
         localTypeParameters: TypeParameter[];      // Local type parameters (undefined if none)
-    }
-
-    export interface InterfaceTypeWithBaseTypes extends InterfaceType {
-        baseTypes: ObjectType[];
+        resolvedBaseConstructorType?: Type;        // Resolved base constructor type of class
+        resolvedBaseTypes: ObjectType[];           // Resolved base types
     }
 
     export interface InterfaceTypeWithDeclaredMembers extends InterfaceType {

src/compiler/types.ts

@@ -426,7 +426,7 @@ namespace ts {
                 // Specialized signatures can have string literals as their parameters' type names
                 return node.parent.kind === SyntaxKind.Parameter;
             case SyntaxKind.ExpressionWithTypeArguments:
-                return true;
+                return !isExpressionWithTypeArgumentsInClassExtendsClause(node);
 
             // Identifiers and qualified names may be type nodes, depending on their context. Climb
             // above them to find the lowest container
@@ -460,7 +460,7 @@ namespace ts {
                 }
                 switch (parent.kind) {
                     case SyntaxKind.ExpressionWithTypeArguments:
-                        return true;
+                        return !isExpressionWithTypeArgumentsInClassExtendsClause(parent);
                     case SyntaxKind.TypeParameter:
                         return node === (<TypeParameterDeclaration>parent).constraint;
                     case SyntaxKind.PropertyDeclaration:
@@ -872,7 +872,6 @@ namespace ts {
                 while (node.parent.kind === SyntaxKind.QualifiedName) {
                     node = node.parent;
                 }
-
                 return node.parent.kind === SyntaxKind.TypeQuery;
             case SyntaxKind.Identifier:
                 if (node.parent.kind === SyntaxKind.TypeQuery) {
@@ -920,6 +919,8 @@ namespace ts {
                         return node === (<ComputedPropertyName>parent).expression;
                     case SyntaxKind.Decorator:
                         return true;
+                    case SyntaxKind.ExpressionWithTypeArguments:
+                        return (<ExpressionWithTypeArguments>parent).expression === node && isExpressionWithTypeArgumentsInClassExtendsClause(parent);
                     default:
                         if (isExpression(parent)) {
                             return true;
@@ -1913,6 +1914,12 @@ namespace ts {
         return token >= SyntaxKind.FirstAssignment && token <= SyntaxKind.LastAssignment;
     }
 
+    export function isExpressionWithTypeArgumentsInClassExtendsClause(node: Node): boolean {
+        return node.kind === SyntaxKind.ExpressionWithTypeArguments &&
+            (<HeritageClause>node.parent).token === SyntaxKind.ExtendsKeyword &&
+            node.parent.parent.kind === SyntaxKind.ClassDeclaration;
+    }
+
     // Returns false if this heritage clause element's expression contains something unsupported
     // (i.e. not a name or dotted name).
     export function isSupportedExpressionWithTypeArguments(node: ExpressionWithTypeArguments): boolean {

src/compiler/utilities.ts

@@ -41,7 +41,10 @@ class TypeWriterWalker {
         var lineAndCharacter = this.currentSourceFile.getLineAndCharacterOfPosition(actualPos);
         var sourceText = ts.getTextOfNodeFromSourceText(this.currentSourceFile.text, node);
 
-        var type = this.checker.getTypeAtLocation(node);
+        // Workaround to ensure we output 'C' instead of 'typeof C' for base class expressions
+        // var type = this.checker.getTypeAtLocation(node);
+        var type = node.parent && ts.isExpressionWithTypeArgumentsInClassExtendsClause(node.parent) && this.checker.getTypeAtLocation(node.parent) || this.checker.getTypeAtLocation(node);
+
         ts.Debug.assert(type !== undefined, "type doesn't exist");
         var symbol = this.checker.getSymbolAtLocation(node);
 

src/harness/typeWriter.ts

@@ -5811,7 +5811,8 @@ namespace ts {
                 node = node.parent;
             }
 
-            return node.parent.kind === SyntaxKind.TypeReference || node.parent.kind === SyntaxKind.ExpressionWithTypeArguments;
+            return node.parent.kind === SyntaxKind.TypeReference ||
+                (node.parent.kind === SyntaxKind.ExpressionWithTypeArguments && !isExpressionWithTypeArgumentsInClassExtendsClause(<ExpressionWithTypeArguments>node.parent));
         }
 
         function isNamespaceReference(node: Node): boolean {

src/services/services.ts

@@ -53,9 +53,9 @@ import Backbone = require("aliasUsage1_backbone");
 
 export class VisualizationModel extends Backbone.Model {
 >VisualizationModel : VisualizationModel
->Backbone.Model : any
+>Backbone.Model : Backbone.Model
 >Backbone : typeof Backbone
->Model : Backbone.Model
+>Model : typeof Backbone.Model
 
     // interesting stuff here
 }

tests/baselines/reference/aliasUsageInAccessorsOfClass.types

@@ -41,9 +41,9 @@ import Backbone = require("aliasUsageInArray_backbone");
 
 export class VisualizationModel extends Backbone.Model {
 >VisualizationModel : VisualizationModel
->Backbone.Model : any
+>Backbone.Model : Backbone.Model
 >Backbone : typeof Backbone
->Model : Backbone.Model
+>Model : typeof Backbone.Model
 
     // interesting stuff here
 }

tests/baselines/reference/aliasUsageInArray.types

@@ -42,9 +42,9 @@ import Backbone = require("aliasUsageInFunctionExpression_backbone");
 
 export class VisualizationModel extends Backbone.Model {
 >VisualizationModel : VisualizationModel
->Backbone.Model : any
+>Backbone.Model : Backbone.Model
 >Backbone : typeof Backbone
->Model : Backbone.Model
+>Model : typeof Backbone.Model
 
     // interesting stuff here
 }