Don't include literals from enum members in completions (microsoft#45588)

* don't include literals from enum members in completions

* add enum symbol to completions test

* use symbol flags for detecting enum member

* use type flags to check for enum member

* fix test

Author: gabritto

src/services/completions.ts

@@ -1500,7 +1500,10 @@ namespace ts.Completions {
 
         log("getCompletionData: Semantic work: " + (timestamp() - semanticStart));
         const contextualType = previousToken && getContextualType(previousToken, position, sourceFile, typeChecker);
-        const literals = mapDefined(contextualType && (contextualType.isUnion() ? contextualType.types : [contextualType]), t => t.isLiteral() ? t.value : undefined);
+
+        const literals = mapDefined(
+            contextualType && (contextualType.isUnion() ? contextualType.types : [contextualType]),
+            t => t.isLiteral() && !(t.flags & TypeFlags.EnumLiteral) ? t.value : undefined);
 
         const recommendedCompletion = previousToken && contextualType && getRecommendedCompletion(previousToken, contextualType, typeChecker);
         return {

tests/cases/fourslash/completionsEnum.ts

@@ -0,0 +1,36 @@
+/// <reference path="fourslash.ts" />
+
+////enum E {
+////	v
+////}
+////const enum ES {
+////	v = "str",
+////    x = "str2"
+////}
+////const e: E = /*a*/;
+////const es: ES = /*b*/;
+
+
+verify.completions({
+    marker: "a",
+    isNewIdentifierLocation: true,
+    excludes: ["0"],
+    includes: [
+        {
+            name: "E",
+            isRecommended: true,
+            sortText: completion.SortText.LocationPriority,
+        }
+    ],
+}, {
+    marker: "b",
+    isNewIdentifierLocation: true,
+    excludes: [`"str"`, `"str2"`],
+    includes: [
+        {
+            name: "ES",
+            isRecommended: true,
+            sortText: completion.SortText.LocationPriority,
+        }
+    ],
+});