From 29d5e4daddc3a97ec81b338b6a3a5ae1892288fe Mon Sep 17 00:00:00 2001
From: Herrington Darkholme <HerringtonDarkholme@users.noreply.github.com>
Date: Tue, 12 Sep 2017 02:21:35 +0800
Subject: [PATCH] fix #18225, fix error message on abstract class instance
 (#18368)

* fix #18225, fix error message on abstract class instance

abstract class check should be inside constructor call

* add new test and accept baseline
---
 src/compiler/checker.ts                       | 20 +++++++++----------
 .../reference/newAbstractInstance.errors.txt  | 10 ++++++++++
 .../reference/newAbstractInstance.js          | 13 ++++++++++++
 tests/cases/compiler/newAbstractInstance.ts   |  3 +++
 4 files changed, 36 insertions(+), 10 deletions(-)
 create mode 100644 tests/baselines/reference/newAbstractInstance.errors.txt
 create mode 100644 tests/baselines/reference/newAbstractInstance.js
 create mode 100644 tests/cases/compiler/newAbstractInstance.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index ff5d1c661e8..66ae64e199b 100644
--- 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
new file mode 100644
index 00000000000..13a5aff9df3
--- /dev/null
+++ 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.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/newAbstractInstance.js b/tests/baselines/reference/newAbstractInstance.js
new file mode 100644
index 00000000000..4a84b42cc20
--- /dev/null
+++ 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
new file mode 100644
index 00000000000..f686aafa005
--- /dev/null
+++ b/tests/cases/compiler/newAbstractInstance.ts
@@ -0,0 +1,3 @@
+abstract class B { }
+declare const b: B;
+new b();