Fixed string completions that require escaping (#55118)

src/services/stringCompletions.ts

@@ -32,6 +32,7 @@ import {
     endsWith,
     ensureTrailingDirectorySeparator,
     equateStringsCaseSensitive,
+    escapeString,
     Extension,
     fileExtensionIsOneOf,
     filter,
@@ -63,6 +64,7 @@ import {
     getSupportedExtensions,
     getSupportedExtensionsWithJsonIfResolveJsonModule,
     getTextOfJsxAttributeName,
+    getTextOfNode,
     getTokenAtPosition,
     hasIndexSignature,
     hasProperty,
@@ -262,8 +264,13 @@ function convertStringLiteralCompletions(
             return { isGlobalCompletion: false, isMemberCompletion: true, isNewIdentifierLocation: completion.hasIndexSignature, optionalReplacementSpan, entries };
         }
         case StringLiteralCompletionKind.Types: {
+            const quoteChar = contextToken.kind === SyntaxKind.NoSubstitutionTemplateLiteral
+                ? CharacterCodes.backtick
+                : startsWith(getTextOfNode(contextToken), "'")
+                ? CharacterCodes.singleQuote
+                : CharacterCodes.doubleQuote;
             const entries = completion.types.map(type => ({
-                name: type.value,
+                name: escapeString(type.value, quoteChar),
                 kindModifiers: ScriptElementKindModifier.none,
                 kind: ScriptElementKind.string,
                 sortText: SortText.LocationPriority,