Merge pull request #909 from pmcelhaney/file-extension-fix

fix #906 -- transpile imports without JS extension properly

.changeset/tough-horses-switch.md

@@ -0,0 +1,5 @@
+---
+"counterfact": patch
+---
+
+fixes an issue where imports without a file extension were not transpiled properly

src/server/convert-js-extensions-to-cjs.ts

@@ -23,7 +23,8 @@ export function convertFileExtensionsToCjs(code: string) {
       ) {
         // Change the module string from "foo.js" to "foo.cjs"
         node.arguments[0].value = node.arguments[0].value.replace(
-          /\.js$/u,
+          // eslint-disable-next-line prefer-named-capture-group, regexp/no-unused-capturing-group, regexp/prefer-named-capture-group
+          /(\.js|\.ts)?$/u,
           ".cjs",
         );
       }

test/server/convert-js-extension-to-cjs.test.ts

@@ -1,11 +1,23 @@
 import { convertFileExtensionsToCjs } from "../../src/server/convert-js-extensions-to-cjs.js";
 
 describe("convertFileExtensionsToCjs", () => {
-  it("converts a local require", () => {
-    expect(convertFileExtensionsToCjs('require("./foo.js");')).toEqual(
-      'require("./foo.cjs");',
-    );
-  });
+  it.each(["./foo.js", "./foo.ts", "./foo"])(
+    "converts %s a local require",
+    (path) => {
+      expect(convertFileExtensionsToCjs(`require("${path}");`)).toEqual(
+        'require("./foo.cjs");',
+      );
+    },
+  );
+
+  it.each(["../foo.js", "../foo.ts", "../foo"])(
+    "converts %s a local require",
+    (path) => {
+      expect(convertFileExtensionsToCjs(`require("${path}");`)).toEqual(
+        'require("../foo.cjs");',
+      );
+    },
+  );
 
   it("does not convert a non-local require", () => {
     expect(convertFileExtensionsToCjs('require("foo/bar.js");')).toEqual(