http: don't throw on Uint8Arrays for http.ServerResponse#write

lib/_http_outgoing.js

@@ -63,6 +63,7 @@ const {
   hideStackFrames
 } = require('internal/errors');
 const { validateString } = require('internal/validators');
+const { isUint8Array } = require('internal/util/types');
 
 const HIGH_WATER_MARK = getDefaultHighWaterMark();
 const { CRLF, debug } = common;
@@ -672,7 +673,7 @@ function write_(msg, chunk, encoding, callback, fromEnd) {
     throw new ERR_STREAM_NULL_VALUES();
   } else if (typeof chunk === 'string') {
     len = Buffer.byteLength(chunk, encoding);
-  } else if (chunk instanceof Buffer) {
+  } else if (isUint8Array(chunk)) {
     len = chunk.length;
   } else {
     throw new ERR_INVALID_ARG_TYPE(

test/parallel/test-http-outgoing-write-types.js

@@ -0,0 +1,24 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+
+const httpServer = http.createServer(common.mustCall(function(req, res) {
+  httpServer.close();
+  assert.throws(() => {
+    res.write(['Throws.']);
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE'
+  });
+  // should not throw
+  res.write('1a2b3c');
+  // should not throw
+  res.write(new Uint8Array(1024));
+  // should not throw
+  res.write(Buffer.from('1'.repeat(1024)));
+  res.end();
+}));
+
+httpServer.listen(0, common.mustCall(function() {
+  http.get({ port: this.address().port });
+}));