1 files changed, 29 insertions, 0 deletions
diff --git a/test/fetch/content-length.js b/test/fetch/content-length.js
new file mode 100644
index 0000000..9264091
--- /dev/null
+++ b/test/fetch/content-length.js
@@ -0,0 +1,29 @@
+'use strict'
+
+const { test } = require('tap')
+const { createServer } = require('http')
+const { once } = require('events')
+const { Blob } = require('buffer')
+const { fetch, FormData } = require('../..')
+
+// https://github.com/nodejs/undici/issues/1783
+test('Content-Length is set when using a FormData body with fetch', async (t) => {
+  const server = createServer((req, res) => {
+    // TODO: check the length's value once the boundary has a fixed length
+    t.ok('content-length' in req.headers) // request has content-length header
+    t.ok(!Number.isNaN(Number(req.headers['content-length'])))
+    res.end()
+  }).listen(0)
+
+  await once(server, 'listening')
+  t.teardown(server.close.bind(server))
+
+  const fd = new FormData()
+  fd.set('file', new Blob(['hello world 👋'], { type: 'text/plain' }), 'readme.md')
+  fd.set('string', 'some string value')
+
+  await fetch(`http://localhost:${server.address().port}`, {
+    method: 'POST',
+    body: fd
+  })
+})