fix microsoft#18225, fix error message on abstract class instance (microsoft#18368)

HerringtonDarkholme · mhegazy · commit 29d5e4daddc3 · 2017-09-11T11:21:35.000-07:00
* fix microsoft#18225, fix error message on abstract class instance abstract class check should be inside constructor call * add new test and accept baseline
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -16128,16 +16128,6 @@ namespace ts {
                 return resolveErrorCall(node);
             }
 
-            // If the expression is a class of abstract type, then it cannot be instantiated.
-            // Note, only class declarations can be declared abstract.
-            // In the case of a merged class-module or class-interface declaration,
-            // only the class declaration node will have the Abstract flag set.
-            const valueDecl = expressionType.symbol && getClassLikeDeclarationOfSymbol(expressionType.symbol);
-            if (valueDecl && hasModifier(valueDecl, ModifierFlags.Abstract)) {
-                error(node, Diagnostics.Cannot_create_an_instance_of_the_abstract_class_0, declarationNameToString(getNameOfDeclaration(valueDecl)));
-                return resolveErrorCall(node);
-            }
-
             // TS 1.0 spec: 4.11
             // If expressionType is of type Any, Args can be any argument
             // list and the result of the operation is of type Any.
@@ -16157,6 +16147,16 @@ namespace ts {
                 if (!isConstructorAccessible(node, constructSignatures[0])) {
                     return resolveErrorCall(node);
                 }
+                // If the expression is a class of abstract type, then it cannot be instantiated.
+                // Note, only class declarations can be declared abstract.
+                // In the case of a merged class-module or class-interface declaration,
+                // only the class declaration node will have the Abstract flag set.
+                const valueDecl = expressionType.symbol && getClassLikeDeclarationOfSymbol(expressionType.symbol);
+                if (valueDecl && hasModifier(valueDecl, ModifierFlags.Abstract)) {
+                    error(node, Diagnostics.Cannot_create_an_instance_of_the_abstract_class_0, declarationNameToString(getNameOfDeclaration(valueDecl)));
+                    return resolveErrorCall(node);
+                }
+
                 return resolveCall(node, constructSignatures, candidatesOutArray);
             }
 
diff --git a/tests/baselines/reference/newAbstractInstance.errors.txt b/tests/baselines/reference/newAbstractInstance.errors.txt
@@ -0,0 +1,10 @@
+tests/cases/compiler/newAbstractInstance.ts(3,1): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
+
+
+==== tests/cases/compiler/newAbstractInstance.ts (1 errors) ====
+    abstract class B { }
+    declare const b: B;
+    new b();
+    ~~~~~~~
+!!! error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
+    
diff --git a/tests/baselines/reference/newAbstractInstance.js b/tests/baselines/reference/newAbstractInstance.js
@@ -0,0 +1,13 @@
+//// [newAbstractInstance.ts]
+abstract class B { }
+declare const b: B;
+new b();
+
+
+//// [newAbstractInstance.js]
+var B = /** @class */ (function () {
+    function B() {
+    }
+    return B;
+}());
+new b();
diff --git a/tests/cases/compiler/newAbstractInstance.ts b/tests/cases/compiler/newAbstractInstance.ts
@@ -0,0 +1,3 @@
+abstract class B { }
+declare const b: B;
+new b();

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+abstract class B { }`
	`2`	`+declare const b: B;`
	`3`	`+new b();`