fix(40432): show as keyword in function context (microsoft#40481)

Author: a-tarasyuk

src/harness/fourslashInterfaceImpl.ts

@@ -1370,6 +1370,7 @@ namespace FourSlashInterface {
             "let",
             "package",
             "yield",
+            "as",
             "async",
             "await",
         ].map(keywordEntry);
@@ -1510,6 +1511,7 @@ namespace FourSlashInterface {
             "let",
             "package",
             "yield",
+            "as",
             "async",
             "await",
         ].map(keywordEntry);

src/services/completions.ts

@@ -2585,7 +2585,6 @@ namespace ts.Completions {
                         || kind === SyntaxKind.ModuleKeyword
                         || kind === SyntaxKind.TypeKeyword
                         || kind === SyntaxKind.NamespaceKeyword
-                        || kind === SyntaxKind.AsKeyword
                         || isTypeKeyword(kind) && kind !== SyntaxKind.UndefinedKeyword;
                 case KeywordCompletionFilters.FunctionLikeBodyKeywords:
                     return isFunctionLikeBodyKeyword(kind);
@@ -2660,6 +2659,7 @@ namespace ts.Completions {
     function isFunctionLikeBodyKeyword(kind: SyntaxKind) {
         return kind === SyntaxKind.AsyncKeyword
             || kind === SyntaxKind.AwaitKeyword
+            || kind === SyntaxKind.AsKeyword
             || !isContextualKeyword(kind) && !isClassMemberCompletionKeyword(kind);
     }
 

tests/cases/fourslash/completionAsKeyword.ts

@@ -0,0 +1,11 @@
+/// <reference path="fourslash.ts" />
+
+////const x = this /*1*/
+////function foo() {
+////    const x = this /*2*/
+////}
+
+verify.completions({
+    marker: ["1", "2"],
+    includes: [{ name: "as", sortText: completion.SortText.GlobalsOrKeywords }]
+});