Fix bug: FunctionDeclaration may have missing name (#20618)

src/services/refactors/extractSymbol.ts

@@ -658,11 +658,10 @@ namespace ts.refactor.extractSymbol {
             case SyntaxKind.Constructor:
                 return "constructor";
             case SyntaxKind.FunctionExpression:
-                return scope.name
-                    ? `function expression '${scope.name.text}'`
-                    : "anonymous function expression";
             case SyntaxKind.FunctionDeclaration:
-                return `function '${scope.name.text}'`;
+                return scope.name
+                    ? `function '${scope.name.text}'`
+                    : "anonymous function";
             case SyntaxKind.ArrowFunction:
                 return "arrow function";
             case SyntaxKind.MethodDeclaration:

tests/cases/fourslash/extract-method-in-anonymous-function-declaration.ts

@@ -0,0 +1,20 @@
+/// <reference path='fourslash.ts' />
+
+////export default function() {
+////    /*start*/0/*end*/
+////}
+
+goTo.select('start', 'end')
+edit.applyRefactor({
+    refactorName: "Extract Symbol",
+    actionName: "function_scope_0",
+    actionDescription: "Extract to inner function in anonymous function",
+    newContent:
+`export default function() {
+    /*RENAME*/newFunction();
+
+    function newFunction() {
+        0;
+    }
+}`
+});