Use getPropertiesForObjectExpression in string literal object completions (#42020)

Co-authored-by: Johanne Enama <jenama@users.noreply.github.com>
Co-authored-by: Kevin Wong <kwong0419@users.noreply.github.com>

Co-authored-by: Johanne Enama <jenama@users.noreply.github.com>
Co-authored-by: Kevin Wong <kwong0419@users.noreply.github.com>

src/services/completions.ts

@@ -2676,7 +2676,7 @@ namespace ts.Completions {
         return jsdoc && jsdoc.tags && (rangeContainsPosition(jsdoc, position) ? findLast(jsdoc.tags, tag => tag.pos < position) : undefined);
     }
 
-    function getPropertiesForObjectExpression(contextualType: Type, completionsType: Type | undefined, obj: ObjectLiteralExpression | JsxAttributes, checker: TypeChecker): Symbol[] {
+    export function getPropertiesForObjectExpression(contextualType: Type, completionsType: Type | undefined, obj: ObjectLiteralExpression | JsxAttributes, checker: TypeChecker): Symbol[] {
         const hasCompletionsType = completionsType && completionsType !== contextualType;
         const type = hasCompletionsType && !(completionsType!.flags & TypeFlags.AnyOrUnknown)
             ? checker.getUnionType([contextualType, completionsType!])

src/services/stringCompletions.ts

@@ -163,7 +163,7 @@ namespace ts.Completions.StringCompletions {
                     //      foo({
                     //          '/*completion position*/'
                     //      });
-                    return stringLiteralCompletionsFromProperties(typeChecker.getContextualType(parent.parent));
+                    return stringLiteralCompletionsForObjectLiteral(typeChecker, parent.parent);
                 }
                 return fromContextualType();
 
@@ -254,6 +254,25 @@ namespace ts.Completions.StringCompletions {
         };
     }
 
+    function stringLiteralCompletionsForObjectLiteral(checker: TypeChecker, objectLiteralExpression: ObjectLiteralExpression): StringLiteralCompletionsFromProperties | undefined {
+        const contextualType = checker.getContextualType(objectLiteralExpression);
+        if (!contextualType) return undefined;
+
+        const completionsType = checker.getContextualType(objectLiteralExpression, ContextFlags.Completions);
+        const symbols = getPropertiesForObjectExpression(
+            contextualType,
+            completionsType,
+            objectLiteralExpression,
+            checker
+        );
+
+        return {
+            kind: StringLiteralCompletionKind.Properties,
+            symbols,
+            hasIndexSignature: hasIndexSignature(contextualType)
+        };
+    }
+
     function getStringLiteralTypes(type: Type | undefined, uniques = new Map<string, true>()): readonly StringLiteralType[] {
         if (!type) return emptyArray;
         type = skipConstraint(type);

tests/cases/fourslash/completionsQuotedObjectLiteralUnion.ts

@@ -0,0 +1,18 @@
+/// <reference path="fourslash.ts" />
+
+//// interface A {
+////   "a-prop": string;
+//// }
+//// 
+//// interface B {
+////   "b-prop": string;
+//// }
+//// 
+//// const obj: A | B = {
+////   "/*1*/"
+//// }
+
+verify.completions({
+  marker: "1",
+  exact: ["a-prop", "b-prop"]
+});