fix(wireprotocol): only send bypassDocumentValidation if true

The bypassDocumentValidation key will only be set if it explicitly
receives a true, otherwise it remains undefined.

Fixes NODE-1492

lib/wireprotocol/2_6_support.js

@@ -43,7 +43,7 @@ var executeWrite = function(pool, bson, type, opsField, ns, ops, options, callba
   }
 
   // Do we have bypassDocumentValidation set, then enable it on the write command
-  if (typeof options.bypassDocumentValidation === 'boolean') {
+  if (options.bypassDocumentValidation === true) {
     writeCommand.bypassDocumentValidation = options.bypassDocumentValidation;
   }
 

lib/wireprotocol/3_2_support.js

@@ -101,7 +101,7 @@ var executeWrite = function(pool, bson, type, opsField, ns, ops, options, callba
   }
 
   // Do we have bypassDocumentValidation set, then enable it on the write command
-  if (typeof options.bypassDocumentValidation === 'boolean') {
+  if (options.bypassDocumentValidation === true) {
     writeCommand.bypassDocumentValidation = options.bypassDocumentValidation;
   }
 

package.json

@@ -34,6 +34,7 @@
     "mongodb-mock-server": "^1.0.0",
     "mongodb-test-runner": "^1.1.18",
     "prettier": "~1.12.0",
+    "sinon": "^6.0.0",
     "snappy": "^6.0.1"
   },
   "peerOptionalDependencies": {

test/tests/unit/wire_protocol_test.js

@@ -0,0 +1,47 @@
+'use strict';
+
+const chai = require('chai');
+const expect = chai.expect;
+const bson = require('bson');
+const sinon = require('sinon');
+const Pool = require('../../../lib/connection/pool.js');
+const wireProtocol2_6 = require('../../../lib/wireprotocol/2_6_support.js');
+const wireProtocol3_2 = require('../../../lib/wireprotocol/3_2_support.js');
+
+describe('WireProtocol', function() {
+  it('2.6 should only set bypassDocumentValidation to true if explicitly set by user to true', function() {
+    testPoolWrite(true, new wireProtocol2_6(), true);
+  });
+
+  it('2.6 should not set bypassDocumentValidation to anything if not explicitly set by user to true', function() {
+    testPoolWrite(false, new wireProtocol2_6(), undefined);
+  });
+
+  it('3.2 should only set bypassDocumentValidation to true if explicitly set by user to true', function() {
+    testPoolWrite(true, new wireProtocol3_2(), true);
+  });
+
+  it('3.2 should not set bypassDocumentValidation to anything if not explicitly set by user to true', function() {
+    testPoolWrite(false, new wireProtocol3_2(), undefined);
+  });
+
+  function testPoolWrite(bypassDocumentValidation, wireProtocol, expected) {
+    const pool = sinon.createStubInstance(Pool);
+    const isMaster = {};
+    const ns = 'fake.namespace';
+    const ops = [{ a: 1 }, { b: 2 }];
+    const options = { bypassDocumentValidation: bypassDocumentValidation };
+
+    wireProtocol.insert(pool, isMaster, ns, bson, ops, options, () => {});
+
+    if (expected) {
+      expect(pool.write.lastCall.args[0])
+        .to.have.nested.property('query.bypassDocumentValidation')
+        .that.equals(expected);
+    } else {
+      expect(pool.write.lastCall.args[0]).to.not.have.nested.property(
+        'query.bypassDocumentValidation'
+      );
+    }
+  }
+});