Fixes #3359

src/Engines/JavaScript.js

@@ -48,30 +48,37 @@ class JavaScript extends TemplateEngine {
 			return "";
 		};
 
+		let originalModData = mod?.data;
+
+		if (typeof mod === "object" && mod.default && this.eleventyConfig.getIsProjectUsingEsm()) {
+			mod = mod.default;
+		}
+
 		if (typeof mod === "string" || mod instanceof Buffer || mod.then) {
 			return { render: () => mod };
 		} else if (typeof mod === "function") {
-			if (mod.prototype && ("data" in mod.prototype || "render" in mod.prototype)) {
+			if (mod.prototype?.data || mod.prototype?.render) {
 				if (!("render" in mod.prototype)) {
 					mod.prototype.render = noop;
 				}
+
+				if (!("data" in mod.prototype) && !mod.data && originalModData) {
+					mod.prototype.data = originalModData;
+				}
+
 				return new mod();
 			} else {
 				return {
+					...(originalModData ? { data: originalModData } : undefined),
 					render: mod,
 				};
 			}
-		} else if (
-			"data" in mod ||
-			"render" in mod ||
-			("default" in mod && this.eleventyConfig.getIsProjectUsingEsm())
-		) {
-			if (!("render" in mod)) {
-				if ("default" in mod) {
-					mod.render = mod.default;
-				} else {
-					mod.render = noop;
-				}
+		} else if ("data" in mod || "render" in mod) {
+			if (!mod.render) {
+				mod.render = noop;
+			}
+			if (!mod.data && originalModData) {
+				mod.data = originalModData;
 			}
 			return mod;
 		}
@@ -191,7 +198,7 @@ class JavaScript extends TemplateEngine {
 			inst = await this.getInstanceFromInputPath(inputPath);
 		}
 
-		if (inst && "render" in inst) {
+		if (inst?.render) {
 			return function (data = {}) {
 				// TODO does this do anything meaningful for non-classes?
 				// `inst` should have a normalized `render` function from _getInstance

test/TemplateRenderJavaScriptTest.js

@@ -1,6 +1,7 @@
 import test from "ava";
 
 import TemplateRender from "../src/TemplateRender.js";
+import Eleventy from "../src/Eleventy.js";
 import EleventyExtensionMap from "../src/EleventyExtensionMap.js";
 
 import { getTemplateConfigInstance } from "./_testHelpers.js";
@@ -302,8 +303,29 @@ test("Class has page property already and keeps it", async (t) => {
   await fn({ avaTest: t, page: { url: "/hi/" } });
 });
 
-test("Class has default export and another one too, issue #3288", async (t) => {
+test("File has default function export and another one too, issue #3288", async (t) => {
   let tr = await getNewTemplateRender("./test/stubs/default-export-and-others.11ty.js");
   let fn = await tr.getCompiledTemplate();
   t.is(await fn(), "<h1>hello</h1>")
 });
+
+test("File has default class export and another one too, issue #3359", async (t) => {
+  let elev = new Eleventy("./test/stubs/default-class-export-and-others.11ty.js", "");
+  let results = await elev.toJSON();
+
+  t.is(results[0].content, "<div>hello</div>")
+});
+
+test("File has default function export and another one for data too, issue #3359", async (t) => {
+  let elev = new Eleventy("./test/stubs/default-function-export-and-named-data.11ty.js", "");
+  let results = await elev.toJSON();
+
+  t.is(results[0].content, "<h1>Hello World</h1>")
+});
+
+test("File has default function export and another one for data too, issue #3359 (CommonJS)", async (t) => {
+  let elev = new Eleventy("./test/stubs/default-function-export-and-named-data.11ty.cjs", "");
+  let results = await elev.toJSON();
+
+  t.is(results[0].content, "<h1>Hello World</h1>")
+});

test/stubs/default-class-export-and-others.11ty.js

@@ -0,0 +1,10 @@
+export default class IndexPage {
+  render(data) {
+    const name = world();
+    return `<div>hello</div>`;
+  }
+}
+
+export function world() {
+  return "World";
+}

test/stubs/default-export-and-others.11ty.js

@@ -1,3 +1,4 @@
 export const foo = "test";
 
+// render
 export default () => "<h1>hello</h1>";

test/stubs/default-function-export-and-named-data.11ty.cjs

@@ -0,0 +1,5 @@
+// render
+module.exports = (data) => `<h1>${data.name} World</h1>`;
+module.exports.data = function() {
+  return { name: "Hello" }
+};

test/stubs/default-function-export-and-named-data.11ty.js

@@ -0,0 +1,6 @@
+export function data() {
+  return { name: "Hello" }
+};
+
+// render
+export default (data) => `<h1>${data.name} World</h1>`;