Fix tagged template literals when the tag is returned from a function call (#1639)

Perryvw · web-flow · commit 9795e996495a · 2025-06-08T16:22:44.000+02:00
diff --git 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
@@ -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" });
+});

Original file line number	Diff line number	Diff line change
`@@ -159,7 +159,7 @@ export function transformContextualCallExpression(`
`159`	`159`	`);`
`160`	`160`	`return lua.createCallExpression(expression, transformedArguments, node);`
`161`	`161`	`}`
`162`		`- } else if (ts.isIdentifier(left)) {`
	`162`	`+ } else if (ts.isIdentifier(left) \|\| ts.isCallExpression(left)) {`
`163`	`163`	`const callContext = context.isStrict ? ts.factory.createNull() : ts.factory.createIdentifier("_G");`
`164`	`164`	`let expression: lua.Expression;`
`165`	`165`	`[expression, transformedArguments] = transformCallWithArguments(`