From ad1b905964490380ec861e57fc969b0f3ed84a15 Mon Sep 17 00:00:00 2001
From: Perryvw <perryvw@users.noreply.github.com>
Date: Fri, 6 Jun 2025 21:57:24 +0200
Subject: [PATCH] Fix tagged template literals when the tag is returned from a
 function call

---
 src/transformation/visitors/call.ts |  2 +-
 test/unit/templateLiterals.spec.ts  | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/transformation/visitors/call.ts b/src/transformation/visitors/call.ts
index 1f9fb521b..d37561910 100644
--- a/src/transformation/visitors/call.ts
+++ b/src/transformation/visitors/call.ts
@@ -159,7 +159,7 @@ export function transformContextualCallExpression(
             );
             return lua.createCallExpression(expression, transformedArguments, node);
         }
-    } else if (ts.isIdentifier(left)) {
+    } else if (ts.isIdentifier(left) || ts.isCallExpression(left)) {
         const callContext = context.isStrict ? ts.factory.createNull() : ts.factory.createIdentifier("_G");
         let expression: lua.Expression;
         [expression, transformedArguments] = transformCallWithArguments(
diff --git a/test/unit/templateLiterals.spec.ts b/test/unit/templateLiterals.spec.ts
index d5dc519a5..318804ee9 100644
--- a/test/unit/templateLiterals.spec.ts
+++ b/test/unit/templateLiterals.spec.ts
@@ -83,3 +83,26 @@ test.each(["string", "'string literal type'", "string & unknown"])(
             .expectToMatchJsResult();
     }
 );
+
+// https://github.com/TypeScriptToLua/TypeScriptToLua/issues/1637
+test("tagged template literal returned from function call (#1637)", () => {
+    util.testModule`
+        function templateFactory() {
+            return (template: TemplateStringsArray) => {
+                return "bar";
+            }
+        }
+        export let result = templateFactory()\`foo\`;
+    `.expectToEqual({ result: "bar" });
+});
+
+test("tagged template literal returned from function call, explicit no context (#1637)", () => {
+    util.testModule`
+        function templateFactory() {
+            return function(this: void, template: TemplateStringsArray) {
+                return "bar";
+            }
+        }
+        export let result = templateFactory()\`foo\`;
+    `.expectToEqual({ result: "bar" });
+});