diff --git a/packages/rollup-plugin-ephemeral/LICENSE b/packages/rollup-plugin-ephemeral/LICENSE
new file mode 100644
index 0000000..257e767
--- /dev/null
+++ b/packages/rollup-plugin-ephemeral/LICENSE
@@ -0,0 +1,15 @@
+ISC License
+
+Copyright (c) 2024 Oleksii Raspopov
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/packages/rollup-plugin-ephemeral/README.md b/packages/rollup-plugin-ephemeral/README.md
new file mode 100644
index 0000000..1004537
--- /dev/null
+++ b/packages/rollup-plugin-ephemeral/README.md
@@ -0,0 +1,3 @@
+# rollup-plugin-ephemeral
+
+Like `@rollup/plugin-virtual` but sometimes you need virtual modules to behave like real files.
diff --git a/packages/rollup-plugin-ephemeral/package.json b/packages/rollup-plugin-ephemeral/package.json
new file mode 100644
index 0000000..fe63d97
--- /dev/null
+++ b/packages/rollup-plugin-ephemeral/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "rollup-plugin-ephemeral",
+  "version": "0.0.1",
+  "type": "module",
+  "main": "./plugin.js",
+  "module": "./plugin.js",
+  "types": "./plugin.d.ts",
+  "keywords": [
+    "rollup-plugin"
+  ],
+  "scripts": {
+    "test": "node --test --experimental-test-coverage"
+  }
+}
diff --git a/packages/rollup-plugin-ephemeral/plugin.d.ts b/packages/rollup-plugin-ephemeral/plugin.d.ts
new file mode 100644
index 0000000..772a2ea
--- /dev/null
+++ b/packages/rollup-plugin-ephemeral/plugin.d.ts
@@ -0,0 +1,4 @@
+import { Plugin } from "rollup";
+
+export function ephemeral(name: string, code: string): Plugin;
+export default ephemeral;
diff --git a/packages/rollup-plugin-ephemeral/plugin.js b/packages/rollup-plugin-ephemeral/plugin.js
new file mode 100644
index 0000000..b9c949e
--- /dev/null
+++ b/packages/rollup-plugin-ephemeral/plugin.js
@@ -0,0 +1,21 @@
+import { resolve, dirname } from "node:path";
+
+export function ephemeral(name, code) {
+	let resolvedId = resolve(name);
+	return {
+		name: `ephemeral_${name}`,
+		resolveId(id, importer) {
+			if (id === name) return name;
+			if (importer != null) {
+				let resolvedImporterId = resolve(dirname(importer), id);
+				if (resolvedImporterId === resolvedId) return resolvedId;
+			}
+			return null;
+		},
+		load(id) {
+			return id === name || id === resolvedId ? code : null;
+		},
+	};
+}
+
+export default ephemeral;
diff --git a/packages/rollup-plugin-ephemeral/test.js b/packages/rollup-plugin-ephemeral/test.js
new file mode 100644
index 0000000..47cac15
--- /dev/null
+++ b/packages/rollup-plugin-ephemeral/test.js
@@ -0,0 +1,43 @@
+import { test } from "node:test";
+import { equal } from "node:assert/strict";
+
+import { resolve } from "node:path";
+
+import { rollup } from "rollup";
+import { ephemeral } from "./plugin.js";
+
+test("generates as modules", async () => {
+	let bundle = await rollup({
+		input: "./index.js",
+		treeshake: false,
+		plugins: [
+			ephemeral(
+				"./index.js",
+				` import { num } from '../branch/index.js';
+					console.log(num); `,
+			),
+			ephemeral("../branch/module.js", "export let num = 13;"),
+			ephemeral(
+				"../branch/index.js",
+				` import { num as base } from './module.js'; 
+					export let num = base * 2;`,
+			),
+		],
+	});
+	let { output } = await bundle.generate({ format: "esm", preserveModules: true });
+	equal(output.length, 3);
+});
+
+test("loads a bare module ID from memory", () => {
+	let plugin = ephemeral("foo", "export default 42");
+	let resolved = plugin.resolveId("foo");
+	equal(resolved, "foo");
+	equal(plugin.load(resolved), "export default 42");
+});
+
+test("loads an absolute path from memory", () => {
+	let plugin = ephemeral("src/foo.js", "export default 42");
+	let resolved = plugin.resolveId("./foo.js", "src/main.js");
+	equal(resolved, resolve("src/foo.js"));
+	equal(plugin.load(resolved), "export default 42");
+});
diff --git a/packages/rollup-plugin-worker-url/plugin.js b/packages/rollup-plugin-worker-url/plugin.js
index 6a98c1b..04e95c5 100644
--- a/packages/rollup-plugin-worker-url/plugin.js
+++ b/packages/rollup-plugin-worker-url/plugin.js
@@ -29,7 +29,7 @@ export function worker() {
 					if (arg.type === "Literal") {
 						// TODO import.meta.url -> id, otherwise the value
 						let { id: fileId } = await this.resolve(arg.value, id);
-						let chunkId = this.emitFile({ type: "chunk", id: fileId });
+						let chunkId = this.emitFile({ type: "chunk", id: fileId, importer: id });
 						ms.overwrite(url.start, url.end, `import.meta.ROLLUP_FILE_URL_${chunkId}`);
 					}
 				}
diff --git a/packages/rollup-plugin-worker-url/test.js b/packages/rollup-plugin-worker-url/test.js
index 445e571..c78f1d4 100644
--- a/packages/rollup-plugin-worker-url/test.js
+++ b/packages/rollup-plugin-worker-url/test.js
@@ -2,7 +2,7 @@ import { test } from "node:test";
 import { equal } from "node:assert/strict";
 
 import { rollup } from "rollup";
-import { ephemeral } from "../rollwright/ephemeral.js";
+import { ephemeral } from "../rollup-plugin-ephemeral/plugin.js";
 import worker from "./plugin.js";
 
 test("simple worker import", async () => {
diff --git a/packages/rollwright/ephemeral.js b/packages/rollwright/ephemeral.js
deleted file mode 100644
index d2bcf2e..0000000
--- a/packages/rollwright/ephemeral.js
+++ /dev/null
@@ -1,21 +0,0 @@
-import { basename } from "node:path";
-
-/**
- * @param {string} filename
- * @param {string} code
- * @returns {import("rollup").Plugin}
- */
-export function ephemeral(filename, code) {
-	let name = basename(filename);
-	return {
-		name: "ephemeral_" + name,
-		resolveId(id, importer) {
-			if (id === name) return id;
-			if (importer === name) return this.resolve(id, filename);
-			return null;
-		},
-		load(id) {
-			return id === name ? code : null;
-		},
-	};
-}
diff --git a/packages/rollwright/fixture.js b/packages/rollwright/fixture.js
index 70fcb1f..0fc360e 100644
--- a/packages/rollwright/fixture.js
+++ b/packages/rollwright/fixture.js
@@ -1,9 +1,9 @@
-import { resolve, relative, dirname, basename } from "node:path";
+import { resolve, dirname, basename } from "node:path";
 
 import { test as base } from "@playwright/test";
 
 import { rollup } from "rollup";
-import { ephemeral } from "./ephemeral.js";
+import { ephemeral } from "../rollup-plugin-ephemeral/plugin.js";
 import { createCoverageCollector } from "./coverage-collector.js";
 import { nodeResolve } from "@rollup/plugin-node-resolve";
 
@@ -49,11 +49,9 @@ async function execute({ page, rlcache, plugins, template, extensions, coverage
 
 	let server = new Hono();
 	let connect = null;
-	let pageContent = template.html ?? template;
-	server.get("/", (ctx) => ctx.html(pageContent));
+	server.get("/", (ctx) => ctx.html(template.html ?? template));
 
-	let root = template.root ?? relative(process.cwd(), dirname(testInfo.file));
-	let statics = serveStatic({ root });
+	let statics = serveStatic({ root: template.root ?? resolve(dirname(testInfo.file)) });
 	server.notFound(async (ctx) => {
 		let response = await statics(ctx, () => Promise.resolve(null));
 		return response != null ? response : ctx.body(null, 404);
@@ -68,10 +66,10 @@ async function execute({ page, rlcache, plugins, template, extensions, coverage
 	async function evaluate(fn, ...args) {
 		let hash = `step_${++id}`;
 		let code = `window.${hash} = ${fn.toString()};`;
-		let filename = resolve(dirname(testInfo.file), `${hash}_${basename(testInfo.file)}`);
-		let input = basename(filename);
+		let rootDir = dirname(testInfo.file);
+		let input = `${hash}_${basename(testInfo.file)}`;
 		inputs.push(input);
-		files.push(ephemeral(filename, code));
+		files.push(ephemeral(input, code));
 		let bundle = await rollup({
 			cache: rlcache.load(),
 			input: inputs,
@@ -91,7 +89,7 @@ async function execute({ page, rlcache, plugins, template, extensions, coverage
 							],
 						})
 					: [],
-				nodeResolve({ browser: true, rootDir: dirname(filename), extensions }),
+				nodeResolve({ browser: true, rootDir, extensions }),
 				...files,
 			],
 			logLevel: "silent",
@@ -101,7 +99,7 @@ async function execute({ page, rlcache, plugins, template, extensions, coverage
 			format: "esm",
 			generatedCode: "es2015",
 			preserveModules: true,
-			dir: dirname(filename),
+			dir: rootDir,
 			minifyInternalExports: false,
 		});
 		rlcache.save(bundle.cache);