Merge pull request #25507 from ajafff/leftmost-expr-tagged-template

getLeftmostExpression: handle TaggedTemplateExpression

Author: DanielRosenwasser

src/compiler/factory.ts

@@ -4355,6 +4355,11 @@ namespace ts {
                 case SyntaxKind.ConditionalExpression:
                     node = (<ConditionalExpression>node).condition;
                     continue;
+
+                case SyntaxKind.TaggedTemplateExpression:
+                    node = (<TaggedTemplateExpression>node).tag;
+                    continue;
+
                 case SyntaxKind.CallExpression:
                     if (stopAtCallExpressions) {
                         return node;

src/testRunner/unittests/factory.ts

@@ -21,6 +21,7 @@ namespace ts {
                 const func = createFunctionExpression(/*modifiers*/ undefined, /*asteriskToken*/ undefined, "fn", /*typeParameters*/ undefined, /*parameters*/ undefined, /*type*/ undefined, createBlock([]));
                 checkExpression(func);
                 checkExpression(createCall(func, /*typeArguments*/ undefined, /*argumentsArray*/ undefined));
+                checkExpression(createTaggedTemplate(func, createNoSubstitutionTemplateLiteral("")));
 
                 checkExpression(createBinary(createLiteral("a"), SyntaxKind.CommaToken, createLiteral("b")));
                 checkExpression(createCommaList([createLiteral("a"), createLiteral("b")]));