diff --git a/js/tests/entrypoint.sh b/js/tests/entrypoint.sh
index 39a41cfe..4765ca61 100755
--- a/js/tests/entrypoint.sh
+++ b/js/tests/entrypoint.sh
@@ -2,4 +2,4 @@
 
 set -e
 
-node /app/test.mjs "${EXERCISE}"
+node /app/test.mjs "/jail/student" "${EXERCISE}"
diff --git a/js/tests/test.mjs b/js/tests/test.mjs
index 99791770..27363c54 100644
--- a/js/tests/test.mjs
+++ b/js/tests/test.mjs
@@ -5,7 +5,7 @@ import * as fs from 'fs'
 const { readFile, writeFile } = fs.promises
 
 global.window = global
-global.fetch = (url) => {
+global.fetch = url => {
   // this is a fake implementation of fetch for the tester
   // -> refer to https://devdocs.io/javascript/global_objects/fetch
   const accessBody = async () => { throw Error('body unavailable') }
@@ -34,7 +34,7 @@ const eq = (a, b) => {
   return true
 }
 
-const name = process.argv[2]
+const [submitPath, name] = process.argv.slice(2)
 const fatal = (...args) => {
   console.error(...args)
   process.exit(1)
@@ -53,6 +53,12 @@ const read = (filename, description) =>
     ifNoEnt(() => fatal(`Missing ${description} for ${name}`)),
   )
 
+const readTest = filename =>
+  readFile(filename, 'utf8').then(test => ({
+    test,
+    mode: filename.endsWith('.js') ? 'function' : 'node',
+  }))
+
 const stackFmt = (err, url) => {
   if (!(err instanceof Error)) {
     throw Error(`Unexpected type thrown: ${typeof err}. usage: throw Error('my message')`)
@@ -62,43 +68,68 @@ const stackFmt = (err, url) => {
   return err.stack.split(url).join(`${name}.js`)
 }
 
-const main = async () => {
-  const [test, rawCode] = await Promise.all([
-    read(joinPath(root, `${name}_test.js`), 'test'),
-    read(`/jail/student/${name}.js`, 'student solution'),
-  ])
+const any = arr =>
+  new Promise(async (s, f) => {
+    let firstError
+    const setError = err => firstError || (firstError = err)
+    await Promise.all(arr.map(p => p.then(s, setError)))
+    f(firstError)
+  })
 
-  // this is a very crude and basic removal of comments
-  // since checking code is only use to prevent cheating
-  // it's not that important if it doesn't work 100% of the time.
-  const code = rawCode.replace(/\/\*[\s\S]*?\*\/|\/\/.*/g, '').trim()
-  if (code.includes('import')) fatal('import keyword not allowed')
-
-  const parts = test.split('// /*/ // ⚡')
-  const [inject, testCode] = parts.length < 2 ? ['', test] : parts
-  const combined = `${inject.trim()}\n${rawCode
-    .replace(inject.trim(), '')
-    .trim()}\n${testCode.trim()}\n`
+const testNode = async ({ test, name }) => {
+  const path = `${submitPath}/${name}.mjs`
+  return {
+    path,
+    url: joinPath(root, `${name}_test.mjs`),
+    code: await read(path, 'student solution'),
+  }
+}
 
-  const b64 = Buffer.from(combined).toString('base64')
-  const url = `data:text/javascript;base64,${b64}`
+const runTests = async ({ url, path, code }) => {
   const { setup, tests } = await import(url).catch(err =>
     fatal(`Unable to execute ${name} solution, error:\n${stackFmt(err, url)}`),
   )
 
   const ctx = (await (setup && setup())) || {}
-  const tools = { eq, fail, wait, code, ctx }
+  const tools = { eq, fail, wait, code, ctx, path }
   for (const [i, t] of tests.entries()) {
     try {
-      if (!await t(tools)) {
+      if (!(await t(tools))) {
         throw Error('Test failed')
       }
     } catch (err) {
-      console.log(`test #${i} failed:\n${t.toString()}\n\nError:`)
+      console.log(`test #${i+1} failed:\n${t.toString()}\n\nError:`)
       fatal(stackFmt(err, url))
     }
   }
   console.log(`${name} passed (${tests.length} tests)`)
 }
 
+const main = async () => {
+  const { test, mode } = await any([
+    readTest(joinPath(root, `${name}_test.js`)),
+    readTest(joinPath(root, `${name}_test.mjs`)),
+  ]).catch(ifNoEnt(() => fatal(`Missing test for ${name}`)))
+
+  if (mode === "node") return runTests(await testNode({ test, name }))
+  const path = `${submitPath}/${name}.js`
+  const rawCode = await read(path, "student solution")
+
+  // this is a very crude and basic removal of comments
+  // since checking code is only use to prevent cheating
+  // it's not that important if it doesn't work 100% of the time.
+  const code = rawCode.replace(/\/\*[\s\S]*?\*\/|\/\/.*/g, "").trim()
+  if (code.includes("import")) fatal("import keyword not allowed")
+
+  const parts = test.split("// /*/ // ⚡")
+  const [inject, testCode] = parts.length < 2 ? ["", test] : parts
+  const combined = `${inject.trim()}\n${rawCode
+    .replace(inject.trim(), "")
+    .trim()}\n${testCode.trim()}\n`
+
+  const b64 = Buffer.from(combined).toString("base64")
+  const url = `data:text/javascript;base64,${b64}`
+  return runTests({ path, code, url })
+}
+
 main().catch(err => fatal(err.stack))