Simple aliases to built-ins (just a key in addExtension) should not…

… use a CustomEngine. Fixes #3339

src/TemplateRender.js

@@ -1,5 +1,6 @@
 import EleventyBaseError from "./Errors/EleventyBaseError.js";
 import EleventyExtensionMap from "./EleventyExtensionMap.js";
+import TemplateEngineManager from "./Engines/TemplateEngineManager.js";
 import CustomEngine from "./Engines/Custom.js";
 
 // import debugUtil from "debug";
@@ -80,7 +81,11 @@ class TemplateRender {
  this.extensionMap.config = this.eleventyConfig;
 
  let extensionEntry = this.extensionMap.getExtensionEntry(name);
- this._engineName = extensionEntry?.aliasKey || extensionEntry?.key;
+ let engineName = extensionEntry?.aliasKey || extensionEntry?.key;
+ if (TemplateEngineManager.isSimpleAlias(extensionEntry)) {
+ engineName = extensionEntry?.key;
+ }
+ this._engineName = engineName;
 
  if (!extensionEntry || !this._engineName) {
  throw new TemplateRenderUnknownEngineError(

test/EleventyTest.js

@@ -1335,6 +1335,24 @@ test("Custom Markdown Render with permalink, Issue #2780", async (t) => {
  t.is(results[0].content.trim(), `<h1>Markdown?</h1>`);
 });
 
+test("Custom Markdown Render with permalink, Issue #2780 #3339", async (t) => {
+ let elev = new Eleventy("./test/stubs-virtual/", undefined, {
+ config: eleventyConfig => {
+ eleventyConfig.addTemplateFormats("markdown");
+ eleventyConfig.addExtension("markdown", {
+ key: "md"
+ });
+
+ eleventyConfig.addTemplate("filename-hi.markdown", `# Markdown?`, { permalink: "/{{ page.fileSlug }}.html" });
+ }
+ });
+
+ let results = await elev.toJSON();
+ t.is(results.length, 1);
+ t.is(results[0].url, `/filename-hi.html`);
+ t.is(results[0].content.trim(), `<h1>Markdown?</h1>`);
+});
+
 test("Test input/output conflicts (input overwrites output), Issue #3327", async (t) => {
  let elev = new Eleventy("./test/stubs-virtual/", "./test/stubs-virtual/", {
  config: eleventyConfig => {