fix: fix request with readable mode is object (nodejs#2279)

In the stream Readable.from(buf) state, the length
of 1 refers to the number of objects, not the length of
buf. Therefore, when the stream mode is set to 'object,'
should not use the length from the state.

lib/core/util.js

@@ -168,7 +168,7 @@ function bodyLength (body) {
     return 0
   } else if (isStream(body)) {
     const state = body._readableState
-    return state && state.ended === true && Number.isFinite(state.length)
+    return state && state.objectMode === false && state.ended === true && Number.isFinite(state.length)
       ? state.length
       : null
   } else if (isBlobLike(body)) {

test/content-length.js

@@ -300,3 +300,32 @@ test('response invalid content length with close', (t) => {
     })
   })
 })
+
+test('request streaming with Readable.from(buf)', (t) => {
+  const server = createServer((req, res) => {
+    req.pipe(res)
+  })
+  t.teardown(server.close.bind(server))
+  server.listen(0, () => {
+    const client = new Client(`http://localhost:${server.address().port}`)
+    t.teardown(client.destroy.bind(client))
+
+    client.request({
+      path: '/',
+      method: 'PUT',
+      body: Readable.from(Buffer.from('hello'))
+    }, (err, data) => {
+      const chunks = []
+      t.error(err)
+      data.body
+        .on('data', (chunk) => {
+          chunks.push(chunk)
+        })
+        .on('end', () => {
+          t.equal(Buffer.concat(chunks).toString(), 'hello')
+          t.pass()
+          t.end()
+        })
+    })
+  })
+})