Merge pull request #4503 from Microsoft/fixClassExpClassfication

Fix classification for class expression

Author: yuit

src/compiler/binder.ts

@@ -973,6 +973,10 @@ namespace ts {
             else {
                 let bindingName = node.name ? node.name.text : "__class";
                 bindAnonymousDeclaration(node, SymbolFlags.Class, bindingName);
+                // Add name of class expression into the map for semantic classifier
+                if (node.name) {
+                    classifiableNames[node.name.text] = node.name.text;
+                }
             }
 
             let symbol = node.symbol;
@@ -1062,4 +1066,4 @@ namespace ts {
                 : declareSymbolAndAddToSymbolTable(node, symbolFlags, symbolExcludes);
         }
     }
-}
+}

tests/cases/fourslash/semanticClassificationClassExpression.ts

@@ -0,0 +1,12 @@
+/// <reference path="fourslash.ts"/>
+
+//// var x = class /*0*/C {}
+//// class /*1*/C {}
+//// class /*2*/D extends class /*3*/B{} { }
+var c = classification;
+verify.semanticClassificationsAre(
+    c.className("C", test.marker("0").position),
+    c.className("C", test.marker("1").position),
+    c.className("D", test.marker("2").position),
+    c.className("B", test.marker("3").position)
+);