diff --git a/lib/index.js b/lib/index.js
index 6cd42dce..9d8a3e8a 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -24,7 +24,7 @@ export type {
 } from './modules/auth/types';
 export type {
   default as ConfirmationResult,
-} from './modules/auth/ConfirmationResult';
+} from './modules/auth/phone/ConfirmationResult';
 export type { default as User } from './modules/auth/User';
 
 /*
diff --git a/lib/modules/auth/index.js b/lib/modules/auth/index.js
index 4288a7e0..4b2863e8 100644
--- a/lib/modules/auth/index.js
+++ b/lib/modules/auth/index.js
@@ -8,7 +8,8 @@ import { getAppEventName, SharedEventEmitter } from '../../utils/events';
 import { getLogger } from '../../utils/log';
 import { getNativeModule } from '../../utils/native';
 import INTERNALS from '../../utils/internals';
-import ConfirmationResult from './ConfirmationResult';
+import ConfirmationResult from './phone/ConfirmationResult';
+import PhoneAuthListener from './phone/PhoneAuthListener';
 
 // providers
 import EmailAuthProvider from './providers/EmailAuthProvider';
@@ -19,8 +20,6 @@ import OAuthProvider from './providers/OAuthProvider';
 import TwitterAuthProvider from './providers/TwitterAuthProvider';
 import FacebookAuthProvider from './providers/FacebookAuthProvider';
 
-import PhoneAuthListener from './PhoneAuthListener';
-
 import type {
   ActionCodeInfo,
   ActionCodeSettings,
diff --git a/lib/modules/auth/ConfirmationResult.js b/lib/modules/auth/phone/ConfirmationResult.js
similarity index 85%
rename from lib/modules/auth/ConfirmationResult.js
rename to lib/modules/auth/phone/ConfirmationResult.js
index fd76e69a..25d701d1 100644
--- a/lib/modules/auth/ConfirmationResult.js
+++ b/lib/modules/auth/phone/ConfirmationResult.js
@@ -2,9 +2,9 @@
  * @flow
  * ConfirmationResult representation wrapper
  */
-import { getNativeModule } from '../../utils/native';
-import type Auth from './';
-import type User from './User';
+import { getNativeModule } from '../../../utils/native';
+import type Auth from '../';
+import type User from '../User';
 
 export default class ConfirmationResult {
   _auth: Auth;
diff --git a/lib/modules/auth/PhoneAuthListener.js b/lib/modules/auth/phone/PhoneAuthListener.js
similarity index 97%
rename from lib/modules/auth/PhoneAuthListener.js
rename to lib/modules/auth/phone/PhoneAuthListener.js
index d85bcace..68bc78fb 100644
--- a/lib/modules/auth/PhoneAuthListener.js
+++ b/lib/modules/auth/phone/PhoneAuthListener.js
@@ -1,6 +1,6 @@
 // @flow
-import INTERNALS from '../../utils/internals';
-import { SharedEventEmitter } from '../../utils/events';
+import INTERNALS from '../../../utils/internals';
+import { SharedEventEmitter } from '../../../utils/events';
 import {
   generatePushID,
   isFunction,
@@ -8,10 +8,10 @@ import {
   isIOS,
   isString,
   nativeToJSError,
-} from '../../utils';
-import { getNativeModule } from '../../utils/native';
+} from '../../../utils';
+import { getNativeModule } from '../../../utils/native';
 
-import type Auth from './';
+import type Auth from '../';
 
 type PhoneAuthSnapshot = {
   state: 'sent' | 'timeout' | 'verified' | 'error',
diff --git a/lib/modules/firestore/DocumentReference.js b/lib/modules/firestore/DocumentReference.js
index 91772833..ebce412b 100644
--- a/lib/modules/firestore/DocumentReference.js
+++ b/lib/modules/firestore/DocumentReference.js
@@ -4,12 +4,11 @@
  */
 import CollectionReference from './CollectionReference';
 import DocumentSnapshot from './DocumentSnapshot';
-import FieldPath from './FieldPath';
-import { mergeFieldPathData } from './utils';
+import { parseUpdateArgs } from './utils';
 import { buildNativeMap } from './utils/serialize';
 import { getAppEventName, SharedEventEmitter } from '../../utils/events';
 import { getLogger } from '../../utils/log';
-import { firestoreAutoId, isFunction, isObject, isString } from '../../utils';
+import { firestoreAutoId, isFunction, isObject } from '../../utils';
 import { getNativeModule } from '../../utils/native';
 
 import type Firestore from './';
@@ -50,9 +49,7 @@ export default class DocumentReference {
 
   get parent(): CollectionReference {
     const parentPath = this._documentPath.parent();
-    if (!parentPath) {
-      throw new Error('Invalid document path');
-    }
+    // $FlowExpectedError: parentPath can never be null
     return new CollectionReference(this._firestore, parentPath);
   }
 
@@ -232,34 +229,7 @@ export default class DocumentReference {
   }
 
   update(...args: any[]): Promise<void> {
-    let data = {};
-    if (args.length === 1) {
-      if (!isObject(args[0])) {
-        throw new Error(
-          'DocumentReference.update failed: If using a single argument, it must be an object.'
-        );
-      }
-      // eslint-disable-next-line prefer-destructuring
-      data = args[0];
-    } else if (args.length % 2 === 1) {
-      throw new Error(
-        'DocumentReference.update failed: Must have either a single object argument, or equal numbers of key/value pairs.'
-      );
-    } else {
-      for (let i = 0; i < args.length; i += 2) {
-        const key = args[i];
-        const value = args[i + 1];
-        if (isString(key)) {
-          data[key] = value;
-        } else if (key instanceof FieldPath) {
-          data = mergeFieldPathData(data, key._segments, value);
-        } else {
-          throw new Error(
-            `DocumentReference.update failed: Argument at index ${i} must be a string or FieldPath`
-          );
-        }
-      }
-    }
+    const data = parseUpdateArgs(args, 'DocumentReference.update');
     const nativeData = buildNativeMap(data);
     return getNativeModule(this._firestore).documentUpdate(
       this.path,
diff --git a/lib/modules/firestore/Path.js b/lib/modules/firestore/Path.js
index 5818b874..dd215cb1 100644
--- a/lib/modules/firestore/Path.js
+++ b/lib/modules/firestore/Path.js
@@ -14,10 +14,7 @@ export default class Path {
   }
 
   get id(): string | null {
-    if (this._parts.length > 0) {
-      return this._parts[this._parts.length - 1];
-    }
-    return null;
+    return this._parts.length > 0 ? this._parts[this._parts.length - 1] : null;
   }
 
   get isDocument(): boolean {
@@ -37,11 +34,9 @@ export default class Path {
   }
 
   parent(): Path | null {
-    if (this._parts.length === 0) {
-      return null;
-    }
-
-    return new Path(this._parts.slice(0, this._parts.length - 1));
+    return this._parts.length > 0
+      ? new Path(this._parts.slice(0, this._parts.length - 1))
+      : null;
   }
 
   /**
@@ -50,10 +45,6 @@ export default class Path {
    */
   static fromName(name: string): Path {
     const parts = name.split('/');
-
-    if (parts.length === 0) {
-      return new Path([]);
-    }
-    return new Path(parts);
+    return parts.length === 0 ? new Path([]) : new Path(parts);
   }
 }
diff --git a/lib/modules/firestore/Transaction.js b/lib/modules/firestore/Transaction.js
index 71cd1b5e..1fa0ce13 100644
--- a/lib/modules/firestore/Transaction.js
+++ b/lib/modules/firestore/Transaction.js
@@ -2,15 +2,13 @@
  * @flow
  * Firestore Transaction representation wrapper
  */
-import { mergeFieldPathData } from './utils';
+import { parseUpdateArgs } from './utils';
 import { buildNativeMap } from './utils/serialize';
 
 import type Firestore from './';
 import type { TransactionMeta } from './TransactionHandler';
 import type DocumentReference from './DocumentReference';
 import DocumentSnapshot from './DocumentSnapshot';
-import { isObject, isString } from '../../utils';
-import FieldPath from './FieldPath';
 import { getNativeModule } from '../../utils/native';
 
 type Command = {
@@ -124,35 +122,7 @@ export default class Transaction {
    */
   update(documentRef: DocumentReference, ...args: Array<any>): Transaction {
     // todo validate doc ref
-    let data = {};
-    if (args.length === 1) {
-      if (!isObject(args[0])) {
-        throw new Error(
-          'Transaction.update failed: If using a single data argument, it must be an object.'
-        );
-      }
-
-      [data] = args;
-    } else if (args.length % 2 === 1) {
-      throw new Error(
-        'Transaction.update failed: Must have either a single object data argument, or equal numbers of data key/value pairs.'
-      );
-    } else {
-      for (let i = 0; i < args.length; i += 2) {
-        const key = args[i];
-        const value = args[i + 1];
-        if (isString(key)) {
-          data[key] = value;
-        } else if (key instanceof FieldPath) {
-          data = mergeFieldPathData(data, key._segments, value);
-        } else {
-          throw new Error(
-            `Transaction.update failed: Argument at index ${i} must be a string or FieldPath`
-          );
-        }
-      }
-    }
-
+    const data = parseUpdateArgs(args, 'Transaction.update');
     this._commandBuffer.push({
       type: 'update',
       path: documentRef.path,
diff --git a/lib/modules/firestore/TransactionHandler.js b/lib/modules/firestore/TransactionHandler.js
index 3b4f5761..1f424a80 100644
--- a/lib/modules/firestore/TransactionHandler.js
+++ b/lib/modules/firestore/TransactionHandler.js
@@ -3,7 +3,6 @@
  * Firestore Transaction representation wrapper
  */
 import { getAppEventName, SharedEventEmitter } from '../../utils/events';
-import { getLogger } from '../../utils/log';
 import { getNativeModule } from '../../utils/native';
 import Transaction from './Transaction';
 import type Firestore from './';
@@ -103,9 +102,7 @@ export default class TransactionHandler {
    * @private
    */
   _remove(id) {
-    // todo confirm pending arg no longer needed
     getNativeModule(this._firestore).transactionDispose(id);
-    // TODO may need delaying to next event loop
     delete this._pending[id];
   }
 
@@ -124,19 +121,17 @@ export default class TransactionHandler {
    * @private
    */
   _handleTransactionEvent(event: TransactionEvent) {
+    // eslint-disable-next-line default-case
     switch (event.type) {
       case 'update':
-        return this._handleUpdate(event);
+        this._handleUpdate(event);
+        break;
       case 'error':
-        return this._handleError(event);
+        this._handleError(event);
+        break;
       case 'complete':
-        return this._handleComplete(event);
-      default:
-        getLogger(this._firestore).warn(
-          `Unknown transaction event type: '${event.type}'`,
-          event
-        );
-        return undefined;
+        this._handleComplete(event);
+        break;
     }
   }
 
diff --git a/lib/modules/firestore/WriteBatch.js b/lib/modules/firestore/WriteBatch.js
index fe4f15a9..5f4fd163 100644
--- a/lib/modules/firestore/WriteBatch.js
+++ b/lib/modules/firestore/WriteBatch.js
@@ -2,10 +2,8 @@
  * @flow
  * WriteBatch representation wrapper
  */
-import FieldPath from './FieldPath';
-import { mergeFieldPathData } from './utils';
+import { parseUpdateArgs } from './utils';
 import { buildNativeMap } from './utils/serialize';
-import { isObject, isString } from '../../utils';
 import { getNativeModule } from '../../utils/native';
 
 import type DocumentReference from './DocumentReference';
@@ -66,38 +64,9 @@ export default class WriteBatch {
   update(docRef: DocumentReference, ...args: any[]): WriteBatch {
     // TODO: Validation
     // validate.isDocumentReference('docRef', docRef);
-    let data = {};
-    if (args.length === 1) {
-      if (!isObject(args[0])) {
-        throw new Error(
-          'WriteBatch.update failed: If using two arguments, the second must be an object.'
-        );
-      }
-      // eslint-disable-next-line prefer-destructuring
-      data = args[0];
-    } else if (args.length % 2 === 1) {
-      throw new Error(
-        'WriteBatch.update failed: Must have a document reference, followed by either a single object argument, or equal numbers of key/value pairs.'
-      );
-    } else {
-      for (let i = 0; i < args.length; i += 2) {
-        const key = args[i];
-        const value = args[i + 1];
-        if (isString(key)) {
-          data[key] = value;
-        } else if (key instanceof FieldPath) {
-          data = mergeFieldPathData(data, key._segments, value);
-        } else {
-          throw new Error(
-            `WriteBatch.update failed: Argument at index ${i} must be a string or FieldPath`
-          );
-        }
-      }
-    }
-
-    const nativeData = buildNativeMap(data);
+    const data = parseUpdateArgs(args, 'WriteBatch.update');
     this._writes.push({
-      data: nativeData,
+      data: buildNativeMap(data),
       path: docRef.path,
       type: 'UPDATE',
     });
diff --git a/lib/modules/firestore/utils/index.js b/lib/modules/firestore/utils/index.js
index 8405183b..6aabeeaf 100644
--- a/lib/modules/firestore/utils/index.js
+++ b/lib/modules/firestore/utils/index.js
@@ -1,6 +1,8 @@
 /**
  * @flow
  */
+import FieldPath from '../FieldPath';
+import { isObject, isString } from '../../../utils';
 
 const buildFieldPathData = (segments: string[], value: any): Object => {
   if (segments.length === 1) {
@@ -39,3 +41,34 @@ export const mergeFieldPathData = (
     [segments[0]]: buildFieldPathData(segments.slice(1), value),
   };
 };
+
+export const parseUpdateArgs = (args: any[], methodName: string) => {
+  let data = {};
+  if (args.length === 1) {
+    if (!isObject(args[0])) {
+      throw new Error(
+        `${methodName} failed: If using a single update argument, it must be an object.`
+      );
+    }
+    [data] = args;
+  } else if (args.length % 2 === 1) {
+    throw new Error(
+      `${methodName} failed: The update arguments must be either a single object argument, or equal numbers of key/value pairs.`
+    );
+  } else {
+    for (let i = 0; i < args.length; i += 2) {
+      const key = args[i];
+      const value = args[i + 1];
+      if (isString(key)) {
+        data[key] = value;
+      } else if (key instanceof FieldPath) {
+        data = mergeFieldPathData(data, key._segments, value);
+      } else {
+        throw new Error(
+          `${methodName} failed: Argument at index ${i} must be a string or FieldPath`
+        );
+      }
+    }
+  }
+  return data;
+};
diff --git a/tests/ios/Podfile.lock b/tests/ios/Podfile.lock
index 0ff42ead..3af0c2e6 100644
--- a/tests/ios/Podfile.lock
+++ b/tests/ios/Podfile.lock
@@ -164,7 +164,7 @@ PODS:
     - React/Core
     - React/fishhook
     - React/RCTBlob
-  - RNFirebase (3.3.1):
+  - RNFirebase (4.0.0-alpha.1):
     - React
   - yoga (0.52.3.React)
 
diff --git a/tests/src/firebase.js b/tests/src/firebase.js
index 6b4800de..58580998 100644
--- a/tests/src/firebase.js
+++ b/tests/src/firebase.js
@@ -4,8 +4,11 @@ import firebase from 'firebase';
 import RNfirebase from './../firebase';
 import DatabaseContents from './tests/support/DatabaseContents';
 
-// RNfirebase.database.enableLogging(true);
-// RNfirebase.firestore.enableLogging(true);
+// Verify logging works
+RNfirebase.database.enableLogging(true);
+RNfirebase.database.enableLogging(false);
+RNfirebase.firestore.enableLogging(true);
+RNfirebase.firestore.enableLogging(false);
 
 // RNfirebase.utils().logLevel = 'debug';
 // RNfirebase.utils().logLevel = 'info';
diff --git a/tests/src/tests/firestore/documentReferenceTests.js b/tests/src/tests/firestore/documentReferenceTests.js
index bd14e3d8..417c6166 100644
--- a/tests/src/tests/firestore/documentReferenceTests.js
+++ b/tests/src/tests/firestore/documentReferenceTests.js
@@ -37,6 +37,17 @@ function documentReferenceTests({ describe, it, context, firebase }) {
         const collection = document.collection('pages');
         collection.id.should.equal('pages');
       });
+
+      it('should error if invalid collection path supplied', () => {
+        (() => {
+          firebase.native
+            .firestore()
+            .doc('documents/doc1')
+            .collection('pages/page1');
+        }).should.throw(
+          'Argument "collectionPath" must point to a collection.'
+        );
+      });
     });
 
     context('delete()', () => {
@@ -586,12 +597,12 @@ function documentReferenceTests({ describe, it, context, firebase }) {
         (() => {
           docRef.update('error');
         }).should.throw(
-          'DocumentReference.update failed: If using a single argument, it must be an object.'
+          'DocumentReference.update failed: If using a single update argument, it must be an object.'
         );
         (() => {
           docRef.update('error1', 'error2', 'error3');
         }).should.throw(
-          'DocumentReference.update failed: Must have either a single object argument, or equal numbers of key/value pairs.'
+          'DocumentReference.update failed: The update arguments must be either a single object argument, or equal numbers of key/value pairs.'
         );
         (() => {
           docRef.update(0, 'error');
diff --git a/tests/src/tests/firestore/firestoreTests.js b/tests/src/tests/firestore/firestoreTests.js
index 94b0c91b..1445069a 100644
--- a/tests/src/tests/firestore/firestoreTests.js
+++ b/tests/src/tests/firestore/firestoreTests.js
@@ -111,12 +111,12 @@ function firestoreTests({ describe, it, context, fcontext, firebase }) {
         (() => {
           batch.update(ref, 'error');
         }).should.throw(
-          'WriteBatch.update failed: If using two arguments, the second must be an object.'
+          'WriteBatch.update failed: If using a single update argument, it must be an object.'
         );
         (() => {
           batch.update(ref, 'error1', 'error2', 'error3');
         }).should.throw(
-          'WriteBatch.update failed: Must have a document reference, followed by either a single object argument, or equal numbers of key/value pairs.'
+          'WriteBatch.update failed: The update arguments must be either a single object argument, or equal numbers of key/value pairs.'
         );
         (() => {
           batch.update(ref, 0, 'error');