From 4579245f36d9c3deccb097da9d5545f9c5c1ab26 Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Sat, 27 Aug 2022 01:43:19 +0300
Subject: [PATCH] fix(50427): allow convert function expressions (#50430)

---
 .../codefixes/convertFunctionToEs6Class.ts     |  6 +++---
 .../fourslash/convertFunctionToEs6Class14.ts   | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 3 deletions(-)
 create mode 100644 tests/cases/fourslash/convertFunctionToEs6Class14.ts

diff --git a/src/services/codefixes/convertFunctionToEs6Class.ts b/src/services/codefixes/convertFunctionToEs6Class.ts
index 6704410afd279..7cc67e1049c8b 100644
--- a/src/services/codefixes/convertFunctionToEs6Class.ts
+++ b/src/services/codefixes/convertFunctionToEs6Class.ts
@@ -22,8 +22,8 @@ namespace ts.codefix {
         }
 
         const ctorDeclaration = ctorSymbol.valueDeclaration;
-        if (isFunctionDeclaration(ctorDeclaration)) {
-            changes.replaceNode(sourceFile, ctorDeclaration, createClassFromFunctionDeclaration(ctorDeclaration));
+        if (isFunctionDeclaration(ctorDeclaration) || isFunctionExpression(ctorDeclaration)) {
+            changes.replaceNode(sourceFile, ctorDeclaration, createClassFromFunction(ctorDeclaration));
         }
         else if (isVariableDeclaration(ctorDeclaration)) {
             const classDeclaration = createClassFromVariableDeclaration(ctorDeclaration);
@@ -233,7 +233,7 @@ namespace ts.codefix {
             return cls;
         }
 
-        function createClassFromFunctionDeclaration(node: FunctionDeclaration): ClassDeclaration {
+        function createClassFromFunction(node: FunctionDeclaration | FunctionExpression): ClassDeclaration {
             const memberElements = createClassElementsFromSymbol(ctorSymbol);
             if (node.body) {
                 memberElements.unshift(factory.createConstructorDeclaration(/*modifiers*/ undefined, node.parameters, node.body));
diff --git a/tests/cases/fourslash/convertFunctionToEs6Class14.ts b/tests/cases/fourslash/convertFunctionToEs6Class14.ts
new file mode 100644
index 0000000000000..22535833abfa5
--- /dev/null
+++ b/tests/cases/fourslash/convertFunctionToEs6Class14.ts
@@ -0,0 +1,18 @@
+/// <reference path="fourslash.ts" />
+
+// @allowNonTsExtensions: true
+// @filename: foo.js
+////const NS = {};
+////NS.Foo = function () {};
+////NS.Foo.prototype.m = function () {};
+
+verify.codeFix({
+    description: "Convert function to an ES2015 class",
+    newFileContent:
+`const NS = {};
+NS.Foo = class {
+    constructor() { }
+    m() { }
+};
+`
+});