add flatbuffers

commit 6da1cf79d90eb242e7da5318241d42279a3df3ba
Author: Max Burke <max@urbanlogiq.com>
Date:   Sun Jan 19 14:47:28 2020 -0800

    [rust] Add use declarations to Rust-generated bindings for imported FB definitions (#5645)

    * Bugfix for Rust generation of union fields named with language keywords

flatbuffers/tests/JavaScriptUnionVectorTest.js

@@ -0,0 +1,57 @@
+var assert = require('assert');
+
+var flatbuffers = require('../js/flatbuffers').flatbuffers;
+var Test = require(process.argv[2]);
+
+function main() {
+  var fbb = new flatbuffers.Builder();
+
+  var charTypes = [
+    Test.Character.Belle,
+    Test.Character.MuLan,
+    Test.Character.BookFan,
+  ];
+
+  Test.Attacker.startAttacker(fbb);
+  Test.Attacker.addSwordAttackDamage(fbb, 5);
+  var attackerOffset = Test.Attacker.endAttacker(fbb);
+
+  var charTypesOffset = Test.Movie.createCharactersTypeVector(fbb, charTypes);
+  var charsOffset = Test.Movie.createCharactersVector(
+    fbb,
+    [
+      Test.BookReader.createBookReader(fbb, 7),
+      attackerOffset,
+      Test.BookReader.createBookReader(fbb, 2),
+    ]
+  );
+
+  Test.Movie.startMovie(fbb);
+  Test.Movie.addCharactersType(fbb, charTypesOffset);
+  Test.Movie.addCharacters(fbb, charsOffset);
+  Test.Movie.finishMovieBuffer(fbb, Test.Movie.endMovie(fbb));
+
+  var buf = new flatbuffers.ByteBuffer(fbb.asUint8Array());
+
+  var movie = Test.Movie.getRootAsMovie(buf);
+
+  assert.strictEqual(movie.charactersTypeLength(), charTypes.length);
+  assert.strictEqual(movie.charactersLength(), movie.charactersTypeLength());
+
+  for (var i = 0; i < charTypes.length; ++i) {
+    assert.strictEqual(movie.charactersType(i), charTypes[i]);
+  }
+
+  var bookReader7 = movie.characters(0, new Test.BookReader());
+  assert.strictEqual(bookReader7.booksRead(), 7);
+
+  var attacker = movie.characters(1, new Test.Attacker());
+  assert.strictEqual(attacker.swordAttackDamage(), 5);
+
+  var bookReader2 = movie.characters(2, new Test.BookReader());
+  assert.strictEqual(bookReader2.booksRead(), 2);
+
+  console.log('FlatBuffers union vector test: completed successfully');
+}
+
+main();