Handle class declarations without names in Extract Symbol

Fixes microsoft#21816

Author: amcasey

src/harness/unittests/extractFunctions.ts

@@ -546,6 +546,13 @@ var q = /*b*/ //c
     /*g*/ + /*h*/ //i
     /*j*/ 2|] /*k*/ //l
     /*m*/; /*n*/ //o`);
+
+    testExtractFunction("extractFunction_NamelessClass", `
+export default class {
+    M() {
+        [#|1 + 1|];
+    }
+}`);
     });
 
     function testExtractFunction(caption: string, text: string, includeLib?: boolean) {

src/services/refactors/extractSymbol.ts

@@ -687,7 +687,7 @@ namespace ts.refactor.extractSymbol {
     }
     function getDescriptionForClassLikeDeclaration(scope: ClassLikeDeclaration): string {
         return scope.kind === SyntaxKind.ClassDeclaration
-            ? `class '${scope.name.text}'`
+            ? scope.name ? `class '${scope.name.text}'` : "anonymous class declaration"
             : scope.name ? `class expression '${scope.name.text}'` : "anonymous class expression";
     }
     function getDescriptionForModuleLikeDeclaration(scope: SourceFile | ModuleBlock): string | SpecialScope {

tests/baselines/reference/extractFunction/extractFunction_NamelessClass.js

@@ -0,0 +1,29 @@
+// ==ORIGINAL==
+
+export default class {
+    M() {
+        /*[#|*/1 + 1/*|]*/;
+    }
+}
+// ==SCOPE::Extract to method in anonymous class declaration==
+
+export default class {
+    M() {
+        this./*RENAME*/newMethod();
+    }
+
+    newMethod() {
+        1 + 1;
+    }
+}
+// ==SCOPE::Extract to function in module scope==
+
+export default class {
+    M() {
+        /*RENAME*/newFunction();
+    }
+}
+
+function newFunction() {
+    1 + 1;
+}

tests/baselines/reference/extractFunction/extractFunction_NamelessClass.ts

@@ -0,0 +1,29 @@
+// ==ORIGINAL==
+
+export default class {
+    M() {
+        /*[#|*/1 + 1/*|]*/;
+    }
+}
+// ==SCOPE::Extract to method in anonymous class declaration==
+
+export default class {
+    M() {
+        this./*RENAME*/newMethod();
+    }
+
+    private newMethod() {
+        1 + 1;
+    }
+}
+// ==SCOPE::Extract to function in module scope==
+
+export default class {
+    M() {
+        /*RENAME*/newFunction();
+    }
+}
+
+function newFunction() {
+    1 + 1;
+}