From 9912b9ce29797ffc77aaf4669f6e575a9b74bc88 Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Thu, 22 Feb 2018 11:51:23 -0800
Subject: [PATCH 1/8] Updates development dependencies

---
 package.json | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/package.json b/package.json
index 7e3e991..f6d9b4b 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,8 @@
     "url": "git://github.com/Simperium/node-simperium.git"
   },
   "scripts": {
-    "test": "mocha --compilers js:babel-core/register --require test/helper test/**",
+    "flow": "flow",
+    "test": "mocha --require babel-core/register --require test/helper test/**",
     "prepublish": "babel -q -d lib/ src/"
   },
   "author": "",
@@ -18,11 +19,12 @@
     "websocket": "^1.0.22"
   },
   "devDependencies": {
-    "babel-cli": "^6.2.0",
-    "babel-core": "^6.2.0",
-    "babel-eslint": "^8.2.1",
-    "babel-preset-es2015": "^6.2.0",
-    "eslint": "^4.17.0",
-    "mocha": "^2.3.4"
+    "babel-cli": "^6.26.0",
+    "babel-core": "^6.26.0",
+    "babel-eslint": "^8.2.2",
+    "babel-preset-es2015": "^6.24.1",
+    "eslint": "^4.18.1",
+    "flow-bin": "^0.66.0",
+    "mocha": "^5.0.1"
   }
 }

From 7ad27005069028bf704e2073bc3146814d5729fd Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Thu, 22 Feb 2018 13:59:47 -0800
Subject: [PATCH 2/8] Adds flowtype to Channel module. Fixes type errors

- Changes 1 codepath for handling simperium change error responses differently than valid change responses
---
 .babelrc                       |   2 +-
 package.json                   |   1 +
 src/simperium/channel.js       | 163 +++++++++++++++++++++++++++------
 test/simperium/channel_test.js |  14 +--
 4 files changed, 144 insertions(+), 36 deletions(-)

diff --git a/.babelrc b/.babelrc
index 8a87b4d..019a465 100644
--- a/.babelrc
+++ b/.babelrc
@@ -1,3 +1,3 @@
 {
-	"presets": ["es2015"]
+	"presets": ["es2015", "flow"]
 }
\ No newline at end of file
diff --git a/package.json b/package.json
index f6d9b4b..e8ce415 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
     "babel-core": "^6.26.0",
     "babel-eslint": "^8.2.2",
     "babel-preset-es2015": "^6.24.1",
+    "babel-preset-flow": "^6.23.0",
     "eslint": "^4.18.1",
     "flow-bin": "^0.66.0",
     "mocha": "^5.0.1"
diff --git a/src/simperium/channel.js b/src/simperium/channel.js
index 5cb5403..0b891c7 100644
--- a/src/simperium/channel.js
+++ b/src/simperium/channel.js
@@ -1,16 +1,62 @@
+// @flow
 /*eslint no-shadow: 0*/
 import { format, inherits } from 'util'
-import { EventEmitter } from 'events'
+import events from 'events'
 import { parseMessage, parseVersionMessage, change as change_util } from './util'
 import JSONDiff from './jsondiff'
 import { v4 as uuid } from 'uuid'
 
+const { EventEmitter } = events;
+
 const jsondiff = new JSONDiff( {list_diff: false} );
 
+type LocalChange = {
+	id: string,
+	ccid: string
+}
+
+type NetworkChange = {
+	id: string,
+	ccids: string[],
+	o: '+' | '-' | 'M',
+	sv: number,
+	ev: number,
+	cv: string,
+	v?: {}
+}
+
+type NetworkChangeErrorResponse = {
+	error: number,
+	id: string,
+	ccids: string[],
+	d: ?{},
+	hasSentFullObject?: boolean
+};
+
+type Ghost = {
+	key: string,
+	version: number,
+	data: {}
+}
+
+class ChangeError extends Error {
+	code: number;
+	changeError: NetworkChangeErrorResponse;
+	change: ?LocalChange;
+
+	constructor( changeError: NetworkChangeErrorResponse, localChange: ?LocalChange ) {
+		super( `${changeError.error} - Could not apply change to: ${changeError.id}` );
+		this.code = changeError.error;
+		this.changeError = changeError;
+		this.change = localChange;
+	}
+}
+
 const UNKNOWN_CV = '?';
 const CODE_INVALID_VERSION = 405;
 const CODE_EMPTY_RESPONSE = 412;
 const CODE_INVALID_DIFF = 440;
+const CODE_DUPLICATE_CHANGE = 409;
 
 const operation = {
 	MODIFY: 'M',
@@ -41,7 +87,7 @@ internal.updateChangeVersion = function( cv ) {
  * @param {String} id - id of the object changed
  * @param {Object} change - the change to apply to the object
  */
-internal.changeObject = function( id, change ) {
+internal.changeObject = function( id: string, change: NetworkChange ) {
 	// pull out the object from the store and apply the change delta
 	var applyChange = internal.performChange.bind( this, change );
 
@@ -153,7 +199,7 @@ internal.removeObject = function( id, acknowledged ) {
 	return this.store.remove( id ).then( notify );
 };
 
-internal.updateAcknowledged = function( change ) {
+internal.updateAcknowledged = function( change: LocalChange ) {
 	var id = change.id;
 	if ( this.localQueue.sent[id] === change ) {
 		this.localQueue.acknowledge( change );
@@ -166,7 +212,7 @@ internal.performChange = function( change ) {
 	return this.store.get( change.id ).then( success );
 };
 
-internal.findAcknowledgedChange = function( change ) {
+internal.findAcknowledgedChange = function( change: { id: string, ccids: string[] } ) {
 	var possibleChange = this.localQueue.sent[change.id];
 	if ( possibleChange ) {
 		if ( ( change.ccids || [] ).indexOf( possibleChange.ccid ) > -1 ) {
@@ -184,12 +230,21 @@ internal.requestObjectVersion = function( id, version ) {
 	} );
 };
 
-internal.applyChange = function( change, ghost ) {
-	const acknowledged = internal.findAcknowledgedChange.bind( this )( change ),
+const applyChangeError = ( channel: Channel, changeError: NetworkChangeErrorResponse ) => {
+	// run on network queue for the relevant bucket object
+	channel.networkQueue.queueFor( changeError.id ).add( ( done ) => {
+		const localChange = internal.findAcknowledgedChange.call( channel, changeError );
+		const error = new ChangeError( changeError, localChange );
+		internal.handleChangeError.call( channel, error, changeError, localChange );
+		done();
+	} )
+};
+
+internal.applyChange = function( change: NetworkChange, ghost: Ghost ) {
+	const acknowledged = internal.findAcknowledgedChange.call( this, change ),
 		updateChangeVersion = internal.updateChangeVersion.bind( this, change.cv );
 
-	let error,
-		original,
+	let original,
 		patch,
 		modified;
 	// attempt to apply the change
@@ -199,19 +254,13 @@ internal.applyChange = function( change, ghost ) {
 	//	 id: '9e9a9616-8174-425a-a1b0-9ed5410f1edc',
 	//	 clientid: 'node-b9776e96-c068-42ae-893a-03f50833bddb',
 	//	 error: 400 }
-	if ( change.error ) {
-		error = new Error( `${change.error} - Could not apply change to: ${ghost.key}` );
-		error.code = change.error;
-		error.change = change;
-		error.ghost = ghost;
-		internal.handleChangeError.call( this, error, change, acknowledged );
-		return;
-	}
 
 	if ( change.o === operation.MODIFY ) {
-		if ( ghost && ( ghost.version !== change.sv ) ) {
+		const matchesStartingVersion = change.sv === ghost.version ||
+			( change.sv === 0 && ( ghost.version === null || ghost.version === undefined ) );
+		if ( ! matchesStartingVersion ) {
 			internal.requestObjectVersion.call( this, change.id, change.sv ).then( data => {
-				internal.applyChange.call( this, change, { version: change.sv, data } )
+				internal.applyChange.call( this, change, { key: ghost.key, version: change.sv, data } )
 			} );
 			return;
 		}
@@ -226,8 +275,12 @@ internal.applyChange = function( change, ghost ) {
 	}
 }
 
-internal.handleChangeError = function( err, change, acknowledged ) {
+internal.handleChangeError = function( err: ChangeError, change: NetworkChangeErrorResponse, acknowledged: ?LocalChange ) {
 	switch ( err.code ) {
+		case CODE_DUPLICATE_CHANGE:
+			if ( ! acknowledged ) {
+				break;
+			}
 		case CODE_INVALID_VERSION:
 		case CODE_INVALID_DIFF: // Invalid version or diff, send full object back to server
 			if ( ! change.hasSentFullObject ) {
@@ -242,7 +295,9 @@ internal.handleChangeError = function( err, change, acknowledged ) {
 
 			break;
 		case CODE_EMPTY_RESPONSE: // Change causes no change, just acknowledge it
-			internal.updateAcknowledged.call( this, acknowledged );
+			if ( acknowledged ) {
+				internal.updateAcknowledged.call( this, acknowledged );
+			}
 			break;
 		default:
 			this.emit( 'error', err, change );
@@ -291,7 +346,7 @@ internal.indexingComplete = function() {
  *
  * @interface GhostStore
  */
-
+interface GhostStore {
 /**
  * Retrieve a Ghost for the given bucket object id
  *
@@ -344,7 +399,7 @@ internal.indexingComplete = function() {
  * @name GhostStore#setChangeVersion
  * @returns {Promise<Void>} - resolves once the change version is saved
  */
-
+}
 
 /**
  * Maintains syncing state for a Simperium bucket.
@@ -364,7 +419,7 @@ internal.indexingComplete = function() {
  * @param {GhostStore} store - data storage for ghost objects
  * @param {String} name - the name of the bucket on Simperium.com
  */
-export default function Channel( appid, access_token, store, name ) {
+export default function Channel( appid: string, access_token: string, store: GhostStore, name: string ) {
 	// Uses an event emitter to handle different Simperium  commands
 	const message = this.message = new EventEmitter();
 
@@ -634,12 +689,63 @@ Channel.prototype.sendChangeVersionRequest = function( cv ) {
 	this.send( format( 'cv:%s', cv ) );
 };
 
+
+type ChangeMessage = {
+	clientid?: string,
+	ccids?: string[],
+	id?: string, // Bucket object being changed
+	o?: string, // TODO: force into valid operation types,
+	v?: {}, // TODO: force into valid change value
+	cv?: string, // Bucket cv this change represents
+	sv?: number,
+	ev?: number,
+	error?: number,
+	d?: {}
+};
+
+const requireProp = <T>( key: string, object: {} ): T => {
+	const value = object[ key ];
+	if ( value ) {
+		return value;
+	}
+	throw new Error( `unexpected value ${ value } for key ${ key } in ${ JSON.stringify( object ) }` );
+}
+
+const asNetworkErrorResponse = ( changeMessage: ChangeMessage ): NetworkChangeErrorResponse => {
+	return {
+		id: requireProp( 'id', changeMessage ),
+		d: changeMessage.d,
+		ccids: requireProp( 'ccids', changeMessage ),
+		error: requireProp( 'error', changeMessage )
+	};
+}
+
+const asNetworkChange = ( changeMessage: ChangeMessage ): NetworkChange => {
+	return {
+		id: requireProp( 'id', changeMessage ),
+		ccids: requireProp( 'ccids', changeMessage ),
+		o: requireProp( 'o', changeMessage ),
+		d: changeMessage.id,
+		cv: requireProp( 'cv', changeMessage ),
+		ev: requireProp( 'ev', changeMessage ),
+		sv: changeMessage.sv ? changeMessage.sv : 0,
+		v: changeMessage.v // v not required for `-` change types
+	};
+}
+
 Channel.prototype.onChanges = function( data ) {
 	var changes = JSON.parse( data ),
 		onChange = internal.changeObject.bind( this );
 
-	changes.forEach( function( change ) {
-		onChange( change.id, change );
+	changes.forEach( ( change ) => {
+		// TODO: parsed change _could_ be an error response
+		// error change shape an non-error change shape are _not_ the same
+		// do validation here and choose appropriate code path
+		if ( change.error ) {
+			applyChangeError( this, asNetworkErrorResponse( change ) );
+		} else {
+			onChange( change.id, asNetworkChange( change ) );
+		}
 	} );
 	// emit ready after all server changes have been applied
 	this.emit( 'ready' );
@@ -866,7 +972,7 @@ LocalQueue.prototype.resendSentChanges = function() {
  *
  * @type {Map<String,Object>} stores specific revisions as a cache
  */
-export const revisionCache = new Map();
+export const revisionCache: Map<string,{}> = new Map();
 
 /**
  * Attempts to fetch an entity's revisions
@@ -966,8 +1072,9 @@ function collectionRevisions( channel, id, callback ) {
 		requestedVersions.add( version );
 
 		// fetch from server or local cache
-		if ( revisionCache.has( `${ id }.${ version }` ) ) {
-			onVersion( id, version, revisionCache.get( `${ id }.${ version }` ) );
+		const cached = revisionCache.get( `${ id }.${ version }` );
+		if ( cached ) {
+			onVersion( id, version, cached );
 		} else {
 			channel.send( `e:${ id }.${ version }` );
 		}
diff --git a/test/simperium/channel_test.js b/test/simperium/channel_test.js
index dd57405..fe501a0 100644
--- a/test/simperium/channel_test.js
+++ b/test/simperium/channel_test.js
@@ -77,9 +77,9 @@ describe( 'Channel', function() {
 			version1 = { content: 'step 1'},
 			version2 = { content: 'step 2'},
 			version3 = { content: 'step 3'},
-			change1 = { o: 'M', ev: 1, cv: 'cv1', id: id, v: diff( {}, version1 )},
-			change2 = { o: 'M', ev: 2, sv: 1, cv: 'cv2', id: id, v: diff( version1, version2 )},
-			change3 = { o: 'M', ev: 3, sv: 2, cv: 'cv3', id: id, v: diff( version2, version3 )},
+			change1 = { o: 'M', ccids: [], ev: 1, cv: 'cv1', id: id, v: diff( {}, version1 )},
+			change2 = { o: 'M', ccids: [], ev: 2, sv: 1, cv: 'cv2', id: id, v: diff( version1, version2 )},
+			change3 = { o: 'M', ccids: [], ev: 3, sv: 2, cv: 'cv3', id: id, v: diff( version2, version3 )},
 			check = fn.counts( 2, function( id, data ) {
 				equal( data.content, 'step 3' );
 				done();
@@ -238,7 +238,7 @@ describe( 'Channel', function() {
 		it( 'should notify bucket after receiving a network change', () => {
 			const id = 'object',
 				data = { content: 'step 1'},
-				change = { o: 'M', ev: 1, cv: 'cv1', id: id, v: diff( {}, data )};
+				change = { o: 'M', ccids: [], ev: 1, cv: 'cv1', id: id, v: diff( {}, data )};
 
 			return new Promise( ( resolve ) => {
 				bucket.on( 'update', () => {
@@ -268,7 +268,7 @@ describe( 'Channel', function() {
 
 			bucket.update( key, {title: 'hello world'}, function() {
 				channel.handleMessage( 'c:' + JSON.stringify( [{
-					o: '-', ev: 1, cv: 'cv1', id: key
+					o: '-', ev: 1, cv: 'cv1', id: key, ccids: []
 				}] ) );
 			} );
 		} ) );
@@ -348,7 +348,7 @@ describe( 'Channel', function() {
 
 			// We receive a remote change from "Hello world" to "Hello kansas"
 			channel.handleMessage( 'c:' + JSON.stringify( [{
-				o: 'M', ev: 2, sv: 1, cv: 'cv1', id: key, v: remoteDiff
+				o: 'M', ev: 2, sv: 1, cv: 'cv1', id: key, v: remoteDiff, ccids: []
 			}] ) );
 
 			// We're changing "Hello world" to "Goodbye world"
@@ -529,7 +529,7 @@ describe( 'Channel', function() {
 		} );
 
 		it( 'should request entire object when source version is out of date', ( done ) => {
-			var change = {o: 'M', id: 'thing', sv: 1, ev: 2, ccid: 'abc', cv: 'new-cv', v: diff( { hello: 'mundo'}, {hello: 'world'} ) };
+			var change = {o: 'M', id: 'thing', sv: 1, ev: 2, ccids: ['abc'], cv: 'new-cv', v: diff( { hello: 'mundo'}, {hello: 'world'} ) };
 			channel.once( 'send', ( data ) => {
 				equal( data, `e:${change.id}.${change.sv}` );
 				channel.once( 'change-version', ( cv ) => {

From bc0498fe958731733fcb177e491b87e196722c0f Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Thu, 22 Feb 2018 14:07:13 -0800
Subject: [PATCH 3/8] eslint and flow errors fail tests

---
 .travis.yml  | 5 ++---
 package.json | 1 +
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 72c41b1..ba10416 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,8 @@
 language: node_js
 sudo: false
-before_install:
-  - npm install -g eslint@2.2 babel-eslint
 script:
-  - eslint .
+  - npm -s run lint
+  - npm -s run flow
   - npm test
 node_js:
   - "4.0"
diff --git a/package.json b/package.json
index e8ce415..2fa04da 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
   },
   "scripts": {
     "flow": "flow",
+    "lint": "eslint .",
     "test": "mocha --require babel-core/register --require test/helper test/**",
     "prepublish": "babel -q -d lib/ src/"
   },

From b7a638d0ee8798822b4139dd0d2769aa045ac60d Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Thu, 22 Feb 2018 14:09:25 -0800
Subject: [PATCH 4/8] Removes outdated TODO statements

---
 src/simperium/channel.js | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/src/simperium/channel.js b/src/simperium/channel.js
index 0b891c7..2138d19 100644
--- a/src/simperium/channel.js
+++ b/src/simperium/channel.js
@@ -247,13 +247,6 @@ internal.applyChange = function( change: NetworkChange, ghost: Ghost ) {
 	let original,
 		patch,
 		modified;
-	// attempt to apply the change
-	// TODO: Handle errors as specified in
-	//	 0:c:[{"ccids": ["0435edf4-3f07-4cc6-bf86-f68e6db8779c"], "id": "9e9a9616-8174-42
-	// { ccids: [ '0435edf4-3f07-4cc6-bf86-f68e6db8779c' ],
-	//	 id: '9e9a9616-8174-425a-a1b0-9ed5410f1edc',
-	//	 clientid: 'node-b9776e96-c068-42ae-893a-03f50833bddb',
-	//	 error: 400 }
 
 	if ( change.o === operation.MODIFY ) {
 		const matchesStartingVersion = change.sv === ghost.version ||
@@ -689,14 +682,13 @@ Channel.prototype.sendChangeVersionRequest = function( cv ) {
 	this.send( format( 'cv:%s', cv ) );
 };
 
-
 type ChangeMessage = {
 	clientid?: string,
 	ccids?: string[],
 	id?: string, // Bucket object being changed
-	o?: string, // TODO: force into valid operation types,
-	v?: {}, // TODO: force into valid change value
-	cv?: string, // Bucket cv this change represents
+	o?: string,
+	v?: {},
+	cv?: string,
 	sv?: number,
 	ev?: number,
 	error?: number,
@@ -738,9 +730,6 @@ Channel.prototype.onChanges = function( data ) {
 		onChange = internal.changeObject.bind( this );
 
 	changes.forEach( ( change ) => {
-		// TODO: parsed change _could_ be an error response
-		// error change shape an non-error change shape are _not_ the same
-		// do validation here and choose appropriate code path
 		if ( change.error ) {
 			applyChangeError( this, asNetworkErrorResponse( change ) );
 		} else {
@@ -972,7 +961,7 @@ LocalQueue.prototype.resendSentChanges = function() {
  *
  * @type {Map<String,Object>} stores specific revisions as a cache
  */
-export const revisionCache: Map<string,{}> = new Map();
+export const revisionCache: Map<string, {}> = new Map();
 
 /**
  * Attempts to fetch an entity's revisions

From a7d22957ac86884c27082f7078e8ac208a95c83b Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Wed, 28 Feb 2018 13:22:00 -0800
Subject: [PATCH 5/8] Adding types and fixing type errors

---
 src/simperium/channel.js                   | 269 +++++++++++++--------
 src/simperium/jsondiff/diff_match_patch.js |  19 +-
 src/simperium/jsondiff/index.js            |   6 +-
 src/simperium/jsondiff/jsondiff.js         |  64 +++--
 src/simperium/util/change.js               |  76 ++++--
 5 files changed, 269 insertions(+), 165 deletions(-)

diff --git a/src/simperium/channel.js b/src/simperium/channel.js
index 2138d19..ee248a2 100644
--- a/src/simperium/channel.js
+++ b/src/simperium/channel.js
@@ -3,8 +3,10 @@
 import { format, inherits } from 'util'
 import events from 'events'
 import { parseMessage, parseVersionMessage, change as change_util } from './util'
+import type { ObjectOperationSet } from './jsondiff';
+import type { BucketChangeType } from './util/change';
 import JSONDiff from './jsondiff'
-import { v4 as uuid } from 'uuid'
+import uuid from 'uuid/v4'
 
 const { EventEmitter } = events;
 
@@ -15,16 +17,25 @@ type LocalChange = {
 	ccid: string
 }
 
-type NetworkChange = {
+type NetworkRemoveOperation = {
+	o: '-',
+	id: string,
+	ccids: string[],
+	cv: string
+}
+
+type NetworkModifyOperation = {
+	o: 'M',
 	id: string,
 	ccids: string[],
-	o: '+' | '-' | 'M',
-	sv: number,
-	ev: number,
 	cv: string,
-	v?: {}
+	ev: number,
+	sv: number,
+	v: ObjectOperationSet
 }
 
+type NetworkChange = NetworkModifyOperation | NetworkRemoveOperation;
+
 type NetworkChangeErrorResponse = {
 	error: number,
 	id: string,
@@ -58,11 +69,6 @@ const CODE_EMPTY_RESPONSE = 412;
 const CODE_INVALID_DIFF = 440;
 const CODE_DUPLICATE_CHANGE = 409;
 
-const operation = {
-	MODIFY: 'M',
-	REMOVE: '-'
-};
-
 // internal methods used as instance methods on a Channel instance
 const internal = {};
 
@@ -72,8 +78,9 @@ const internal = {};
  * @param {String} cv - the change version synced
  * @returns {Promise<String>} the saved `cv`
  */
-internal.updateChangeVersion = function( cv ) {
-	return this.store.setChangeVersion( cv ).then( () => {
+internal.updateChangeVersion = function( cv ): Promise<string> {
+	const store: GhostStore = this.store;
+	return store.setChangeVersion( cv ).then( () => {
 		// A unit test currently relies on this event, otherwise we can remove it
 		this.emit( 'change-version', cv );
 		return cv;
@@ -88,11 +95,15 @@ internal.updateChangeVersion = function( cv ) {
  * @param {Object} change - the change to apply to the object
  */
 internal.changeObject = function( id: string, change: NetworkChange ) {
-	// pull out the object from the store and apply the change delta
-	var applyChange = internal.performChange.bind( this, change );
-
-	this.networkQueue.queueFor( id ).add( function( done ) {
-		return applyChange().then( done, done );
+	// Add types for now until function is changed to accept a Channel
+	const channel: Channel = this;
+	const store: GhostStore = channel.store;
+	const queue: NetworkQueue = channel.networkQueue;
+
+	queue.queueFor( id ).add( ( done ) => {
+		store.get( change.id )
+			.then( ghost => internal.applyChange.call( channel, change, ghost ) )
+			.then( done, done );
 	} );
 };
 
@@ -106,12 +117,11 @@ internal.changeObject = function( id: string, change: NetworkChange ) {
  * @param {Object} object - object literal of the data that the change should produce
  * @param {Object} ghost - the ghost version used to produce the change object
  */
-internal.buildModifyChange = function( id, object, ghost ) {
-	var payload = change_util.buildChange( change_util.type.MODIFY, id, object, ghost ),
-		empty = true,
-		key;
+internal.buildModifyChange = function( id: string, object: {}, ghost: Ghost ) {
+	const payload = change_util.buildChange( change_util.type.MODIFY, id, object, ghost );
+	let empty = true;
 
-	for ( key in payload.v ) {
+	for ( let key in payload.v ) {
 		if ( key ) {
 			empty = false;
 			break;
@@ -135,9 +145,10 @@ internal.buildModifyChange = function( id, object, ghost ) {
  * @param {String} id - object to remove
  * @param {Object} ghost - current ghost object for the given id
  */
-internal.buildRemoveChange = function( id, ghost ) {
-	var payload = change_util.buildChange( change_util.type.REMOVE, id, {}, ghost );
-	this.localQueue.queue( payload );
+internal.buildRemoveChange = function( id: string, ghost: Ghost ) {
+	const payload = change_util.buildChange( '-', id, {}, ghost );
+	const localQueue: LocalQueue = this.localQueue;
+	localQueue.queue( payload );
 };
 
 internal.diffAndSend = function( id, object ) {
@@ -152,7 +163,7 @@ internal.removeAndSend = function( id ) {
 
 // We've receive a full object from the network. Update the local instance and
 // notify of the new object version
-internal.updateObjectVersion = function( id, version, data, original, patch, acknowledged ) {
+internal.updateObjectVersion = function( id: string, version: number, data: {}, original, patch, acknowledged ): Promise<*> {
 	var notify,
 		changes,
 		change,
@@ -188,7 +199,7 @@ internal.updateObjectVersion = function( id, version, data, original, patch, ack
 	return this.store.put( id, version, data ).then( notify );
 };
 
-internal.removeObject = function( id, acknowledged ) {
+internal.removeObject = function( id, acknowledged ): Promise<*> {
 	var notify;
 	if ( !acknowledged ) {
 		notify = this.emit.bind( this, 'remove', id );
@@ -196,7 +207,8 @@ internal.removeObject = function( id, acknowledged ) {
 		notify = internal.updateAcknowledged.bind( this, acknowledged );
 	}
 
-	return this.store.remove( id ).then( notify );
+	const store: GhostStore = this.store;
+	return store.remove( id ).then( notify );
 };
 
 internal.updateAcknowledged = function( change: LocalChange ) {
@@ -207,13 +219,8 @@ internal.updateAcknowledged = function( change: LocalChange ) {
 	}
 };
 
-internal.performChange = function( change ) {
-	var success = internal.applyChange.bind( this, change );
-	return this.store.get( change.id ).then( success );
-};
-
-internal.findAcknowledgedChange = function( change: { id: string, ccids: string[] } ) {
-	var possibleChange = this.localQueue.sent[change.id];
+internal.findAcknowledgedChange = function( change: { id: string, ccids: string[] } ): ?LocalChange {
+	const possibleChange: ?LocalChange = this.localQueue.sent[change.id];
 	if ( possibleChange ) {
 		if ( ( change.ccids || [] ).indexOf( possibleChange.ccid ) > -1 ) {
 			return possibleChange;
@@ -221,7 +228,7 @@ internal.findAcknowledgedChange = function( change: { id: string, ccids: string[
 	}
 };
 
-internal.requestObjectVersion = function( id, version ) {
+internal.requestObjectVersion = function( id: string, version: number ) {
 	return new Promise( resolve => {
 		this.once( `version.${ id }.${ version }`, data => {
 			resolve( data );
@@ -232,7 +239,8 @@ internal.requestObjectVersion = function( id, version ) {
 
 const applyChangeError = ( channel: Channel, changeError: NetworkChangeErrorResponse ) => {
 	// run on network queue for the relevant bucket object
-	channel.networkQueue.queueFor( changeError.id ).add( ( done ) => {
+	const networkQueue: NetworkQueue = channel.networkQueue;
+	networkQueue.queueFor( changeError.id ).add( ( done ) => {
 		const localChange = internal.findAcknowledgedChange.call( channel, changeError );
 		const error = new ChangeError( changeError, localChange );
 		internal.handleChangeError.call( channel, error, changeError, localChange );
@@ -240,7 +248,7 @@ const applyChangeError = ( channel: Channel, changeError: NetworkChangeErrorResp
 	} )
 };
 
-internal.applyChange = function( change: NetworkChange, ghost: Ghost ) {
+internal.applyChange = function( change: NetworkChange, ghost: Ghost ): Promise<any> {
 	const acknowledged = internal.findAcknowledgedChange.call( this, change ),
 		updateChangeVersion = internal.updateChangeVersion.bind( this, change.cv );
 
@@ -248,14 +256,19 @@ internal.applyChange = function( change: NetworkChange, ghost: Ghost ) {
 		patch,
 		modified;
 
-	if ( change.o === operation.MODIFY ) {
+	if ( change.o === '-' ) {
+		return internal.removeObject.call( this, change.id, acknowledged ).then( updateChangeVersion );
+	}
+
+	if ( change.o === 'M' ) {
+		const modifyChange: NetworkModifyOperation = change;
 		const matchesStartingVersion = change.sv === ghost.version ||
 			( change.sv === 0 && ( ghost.version === null || ghost.version === undefined ) );
 		if ( ! matchesStartingVersion ) {
 			internal.requestObjectVersion.call( this, change.id, change.sv ).then( data => {
-				internal.applyChange.call( this, change, { key: ghost.key, version: change.sv, data } )
+				internal.applyChange.call( this, change, { key: ghost.key, version: modifyChange.sv, data } )
 			} );
-			return;
+			return Promise.resolve();
 		}
 
 		original = ghost.data;
@@ -263,9 +276,10 @@ internal.applyChange = function( change: NetworkChange, ghost: Ghost ) {
 		modified = jsondiff.apply_object_diff( original, patch );
 		return internal.updateObjectVersion.call( this, change.id, change.ev, modified, original, patch, acknowledged )
 			.then( updateChangeVersion );
-	} else if ( change.o === operation.REMOVE ) {
-		return internal.removeObject.bind( this )( change.id, acknowledged ).then( updateChangeVersion );
 	}
+	// Only changes of REMOVE and MODIFY are possible
+	// Should changes of ADD throw an error?
+	return Promise.resolve();
 }
 
 internal.handleChangeError = function( err: ChangeError, change: NetworkChangeErrorResponse, acknowledged: ?LocalChange ) {
@@ -340,58 +354,65 @@ internal.indexingComplete = function() {
  * @interface GhostStore
  */
 interface GhostStore {
-/**
- * Retrieve a Ghost for the given bucket object id
- *
- * @function
- * @name GhostStore#get
- * @param {String} id - bucket object id
- * @returns {Promise<Ghost>} - the ghost for this object
- */
+	/**
+	 * Retrieve a Ghost for the given bucket object id
+	 *
+	 * @function
+	 * @name GhostStore#get
+	 * @param {String} id - bucket object id
+	 * @returns {Promise<Ghost>} - the ghost for this object
+	 */
+	 get( id: string ): Promise<Ghost>;
 
-/**
- * Save a ghost in the store.
- *
- * @function
- * @name GhostStore#put
- * @param {String} id - bucket object id
- * @param {Number} version - version of ghost data
- * @param {Object} data - object literal to save as this ghost's data for this version
- * @returns {Promise<Ghost>} - the ghost for this object
- */
+	/**
+	 * Save a ghost in the store.
+	 *
+	 * @function
+	 * @name GhostStore#put
+	 * @param {String} id - bucket object id
+	 * @param {Number} version - version of ghost data
+	 * @param {Object} data - object literal to save as this ghost's data for this version
+	 * @returns {Promise<Ghost>} - the ghost for this object
+	 */
+	 put(id: string, version: number, data: {}): Promise<Ghost>;
 
-/**
- * Delete a Ghost from the store.
- *
- * @function
- * @name GhostStore#remove
- * @param {String} id - bucket object id
- * @returns {Promise<Ghost>} - the ghost for this object
- */
+	/**
+	 * Delete a Ghost from the store.
+	 *
+	 * @function
+	 * @name GhostStore#remove
+	 * @param {String} id - bucket object id
+	 * @returns {Promise<Ghost>} - the ghost for this object
+	 */
+	 remove(id: string): Promise<Ghost>;
 
-/**
- * Iterate over existing Ghost objects with the given callback.
- *
- * @function
- * @name GhostStore#eachGhost
- * @param {ghostIterator} - function to run against each ghost
- */
+	/**
+	 * Iterate over existing Ghost objects with the given callback.
+	 *
+	 * @function
+	 * @name GhostStore#eachGhost
+	 * @param {ghostIterator} - function to run against each ghost
+	 */
+	 eachGhost(iterator: (Ghost) => void): void;
 
-/**
- * Get the current change version (cv) that this channel has synced.
- *
- * @function
- * @name GhostStore#getChangeVersion
- * @returns {Promise<String>} - the current change version for the bucket
- */
+	/**
+	 * Get the current change version (cv) that this channel has synced.
+	 *
+	 * @function
+	 * @name GhostStore#getChangeVersion
+	 * @returns {Promise<String>} - the current change version for the bucket
+	 */
+	 getChangeVersion(): Promise<string>;
 
-/**
- * Set the current change version.
- *
- * @function
- * @name GhostStore#setChangeVersion
- * @returns {Promise<Void>} - resolves once the change version is saved
- */
+	/**
+	 * Set the current change version.
+	 *
+	 * @function
+	 * @name GhostStore#setChangeVersion
+	 * @param {string} changeVersion - new change version
+	 * @returns {Promise<Void>} - resolves once the change version is saved
+	 */
+	 setChangeVersion(changeVersion: string): Promise<void>;
 }
 
 /**
@@ -686,7 +707,7 @@ type ChangeMessage = {
 	clientid?: string,
 	ccids?: string[],
 	id?: string, // Bucket object being changed
-	o?: string,
+	o?: BucketChangeType,
 	v?: {},
 	cv?: string,
 	sv?: number,
@@ -696,11 +717,11 @@ type ChangeMessage = {
 };
 
 const requireProp = <T>( key: string, object: {} ): T => {
-	const value = object[ key ];
+	const value: T = object[ key ];
 	if ( value ) {
 		return value;
 	}
-	throw new Error( `unexpected value ${ value } for key ${ key } in ${ JSON.stringify( object ) }` );
+	throw new Error( `unexpected value for key ${ key } in ${ JSON.stringify( object ) }` );
 }
 
 const asNetworkErrorResponse = ( changeMessage: ChangeMessage ): NetworkChangeErrorResponse => {
@@ -712,17 +733,53 @@ const asNetworkErrorResponse = ( changeMessage: ChangeMessage ): NetworkChangeEr
 	};
 }
 
+class ProtocolError extends Error {
+}
+
 const asNetworkChange = ( changeMessage: ChangeMessage ): NetworkChange => {
-	return {
-		id: requireProp( 'id', changeMessage ),
-		ccids: requireProp( 'ccids', changeMessage ),
-		o: requireProp( 'o', changeMessage ),
-		d: changeMessage.id,
-		cv: requireProp( 'cv', changeMessage ),
-		ev: requireProp( 'ev', changeMessage ),
-		sv: changeMessage.sv ? changeMessage.sv : 0,
-		v: changeMessage.v // v not required for `-` change types
-	};
+	const operation: ?BucketChangeType = changeMessage.o;
+
+	if ( ! changeMessage.ccids ) {
+		throw new ProtocolError( 'nework change missing ccids' );
+	}
+
+	if ( ! changeMessage.cv ) {
+		throw new ProtocolError( 'netwock change missing change version (cv)');
+	}
+
+	if ( ! changeMessage.id ) {
+		throw new ProtocolError( 'network change missing id');
+	}
+
+	if ( operation === '-' ) {
+		return {
+			id: changeMessage.id,
+			cv: changeMessage.cv,
+			ccids: changeMessage.ccids,
+			o: '-',
+			sv: changeMessage.sv ? changeMessage.sv : 0,
+		}
+	}
+	if ( operation === 'M' ) {
+		if ( ! changeMessage.ev ) {
+			throw new ProtocolError( 'network modify change missing ev' );
+		}
+
+		if ( ! changeMessage.v ) {
+			throw new ProtocolError( 'network modify change missing v' );
+		}
+
+		return {
+			id: changeMessage.id,
+			cv: changeMessage.cv,
+			ccids: changeMessage.ccids,
+			o: 'M',
+			sv: changeMessage.sv ? changeMessage.sv : 0,
+			ev: changeMessage.ev,
+			v: changeMessage.v
+		}
+	}
+	throw new Error( `Invalid change type ${ operation ? operation : '<null>' } in c:${ JSON.stringify( changeMessage )}` );
 }
 
 Channel.prototype.onChanges = function( data ) {
@@ -787,7 +844,7 @@ function Queue() {
 inherits( Queue, EventEmitter );
 
 // Add a function at the end of the queue
-Queue.prototype.add = function( fn ) {
+Queue.prototype.add = function( fn: ( () => void ) => void ): Queue {
 	this.queue.push( fn );
 	this.start();
 	return this;
@@ -814,7 +871,7 @@ Queue.prototype.run = function() {
 	fn( this.run.bind( this ) );
 }
 
-function LocalQueue( store ) {
+function LocalQueue( store: GhostStore ) {
 	this.store = store;
 	this.sent = {};
 	this.queues = {};
diff --git a/src/simperium/jsondiff/diff_match_patch.js b/src/simperium/jsondiff/diff_match_patch.js
index 6f97a7a..9bdccea 100644
--- a/src/simperium/jsondiff/diff_match_patch.js
+++ b/src/simperium/jsondiff/diff_match_patch.js
@@ -1,4 +1,3 @@
-module.exports = diff_match_patch;
 
 /**
  * Diff Match and Patch
@@ -29,7 +28,7 @@ module.exports = diff_match_patch;
  * Class containing the diff, match and patch methods.
  * @constructor
  */
-function diff_match_patch() {
+export default function diff_match_patch() {
 
   // Defaults.
   // Redefine these in your program to override the defaults.
@@ -65,9 +64,9 @@ function diff_match_patch() {
  * [[DIFF_DELETE, 'Hello'], [DIFF_INSERT, 'Goodbye'], [DIFF_EQUAL, ' world.']]
  * which means: delete 'Hello', add 'Goodbye' and keep ' world.'
  */
-var DIFF_DELETE = -1;
-var DIFF_INSERT = 1;
-var DIFF_EQUAL = 0;
+export const DIFF_DELETE = -1;
+export const DIFF_INSERT = 1;
+export const DIFF_EQUAL = 0;
 
 /** @typedef {{0: number, 1: string}} */
 diff_match_patch.Diff;
@@ -2183,13 +2182,3 @@ diff_match_patch.patch_obj.prototype.toString = function() {
   }
   return text.join('').replace(/%20/g, ' ');
 };
-
-
-// Export these global variables so that they survive Google's JS compiler.
-// In a browser, 'this' will be 'window'.
-// Users of node.js should 'require' the uncompressed version since Google's
-// JS compiler may break the following exports for non-browser environments.
-module.exports['diff_match_patch'] = diff_match_patch;
-module.exports['DIFF_DELETE'] = DIFF_DELETE;
-module.exports['DIFF_INSERT'] = DIFF_INSERT;
-module.exports['DIFF_EQUAL'] = DIFF_EQUAL;
\ No newline at end of file
diff --git a/src/simperium/jsondiff/index.js b/src/simperium/jsondiff/index.js
index 568cfa5..85344f8 100644
--- a/src/simperium/jsondiff/index.js
+++ b/src/simperium/jsondiff/index.js
@@ -1,8 +1,12 @@
+// @flow
 import JSONDiff from './jsondiff'
 import diff_match_patch from './diff_match_patch'
+import type { ObjectOperationSet } from './jsondiff';
+
+export type { ObjectOperationSet };
 
 export { JSONDiff as jsondiff, diff_match_patch }
 
-export default function init( options ) {
+export default function init( options: ?{ list_diff: boolean } ): JSONDiff {
 	return new JSONDiff( options );
 }
diff --git a/src/simperium/jsondiff/jsondiff.js b/src/simperium/jsondiff/jsondiff.js
index 8ff9f16..579fd06 100644
--- a/src/simperium/jsondiff/jsondiff.js
+++ b/src/simperium/jsondiff/jsondiff.js
@@ -1,14 +1,46 @@
-var diff_match_patch = require('./diff_match_patch');
+// @flow
+import diff_match_patch, { DIFF_EQUAL, DIFF_INSERT, DIFF_DELETE } from './diff_match_patch';
 
-// stolen from https://raw.github.com/Simperium/jsondiff/master/src/jsondiff.js
-(function() {
-  var jsondiff,
-    __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; },
-    __hasProp = Object.prototype.hasOwnProperty;
+// These ar the types of changes that can be applied to a value
+type PropertyChangeType
+  = '+' // add the value at `v`
+  | '-' // remove the key from the object
+  | 'r' // replace the key value of object with `v`
+  | 'I' // increment the value at key, requires the value to be numerical
+  | 'L' // apply a list diff operation to the property at v
+  | 'O' // apply an object diff operation to the property at v
+  | 'd' // apply a diff match patch operation to the property at v
+
+// Add a value, will exist within an object operation
+type AddOperation = { o: '+', v: any }
+type ReplaceOperation = { o: 'r', v: any }
+
+type RemoveOperation = { o: '-' };
+type IncrementOperation = { o: 'I', v: number }
+type ListOperation = { o: 'L', v: { [key: number]: Operation } };
+// an object diff is indexed by the key name that the diff applies to
+
+export type ObjectOperationSet = { [key: string]: Operation };
+type ObjectOperation = { o: 'O', v: ObjectOperationSet };
 
-  jsondiff = (function() {
+type DiffMatchPathOperation = { o: 'd', v: string }
 
-    function jsondiff(options) {
+
+export type Operation
+  // adds a value to an object, is a child of another change
+  = AddOperation
+  | ReplaceOperation
+  | RemoveOperation
+  | IncrementOperation
+  | ListOperation
+  | ObjectOperation
+  | DiffMatchPathOperation
+
+// stolen from https://raw.github.com/Simperium/jsondiff/master/src/jsondiff.js
+    const __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };
+    const __hasProp = Object.prototype.hasOwnProperty;
+
+    export default function jsondiff(options: ? { list_diff: boolean } ) {
       this.options = options || {list_diff: true};
       this.patch_apply_with_offsets = __bind(this.patch_apply_with_offsets, this);
       this.transform_object_diff = __bind(this.transform_object_diff, this);
@@ -168,7 +200,7 @@ var diff_match_patch = require('./diff_match_patch');
       return diffs;
     };
 
-    jsondiff.prototype.object_diff = function(a, b) {
+    jsondiff.prototype.object_diff = function(a: {}, b: {}): DiffSet {
       var diffs, key;
       diffs = {};
       if (!(a != null) || !(b != null)) return {};
@@ -298,8 +330,8 @@ var diff_match_patch = require('./diff_match_patch');
       return patched;
     };
 
-    jsondiff.prototype.apply_object_diff = function(s, diffs) {
-      var dmp_diffs, dmp_patches, dmp_result, key, op, patched;
+    jsondiff.prototype.apply_object_diff = function(s: {}, diffs: ObjectOperationSet): {} {
+      var dmp_diffs, dmp_patches, dmp_result, key, op, patched: {};
       patched = this.deepCopy(s);
       for (key in diffs) {
         if (!__hasProp.call(diffs, key)) continue;
@@ -429,7 +461,7 @@ var diff_match_patch = require('./diff_match_patch');
       return ad_new;
     };
 
-    jsondiff.prototype.transform_object_diff = function(ad, bd, s) {
+    jsondiff.prototype.transform_object_diff = function(ad: ObjectOperationSet, bd: ObjectOperationSet, s: {}): ?ObjectOperationSet {
       var a_patches, ab_text, ad_new, aop, b_patches, b_text, bop, dmp_diffs, dmp_patches, dmp_result, key, sk, _ref;
       ad_new = this.deepCopy(ad);
       for (key in ad) {
@@ -611,11 +643,3 @@ var diff_match_patch = require('./diff_match_patch');
     text = text.substring(nullPadding.length, text.length - nullPadding.length);
     return text;
   };
-
-    return jsondiff;
-
-  })();
-
-  module.exports = jsondiff;
-
-}).call();
\ No newline at end of file
diff --git a/src/simperium/util/change.js b/src/simperium/util/change.js
index 96c8a72..943c080 100644
--- a/src/simperium/util/change.js
+++ b/src/simperium/util/change.js
@@ -1,10 +1,13 @@
-import { v4 as uuid } from 'uuid'
+// @flow
+import uuid from 'uuid/v4'
 import jsondiff from '../jsondiff'
+import type { ObjectOperationSet } from '../jsondiff';
 
-const changeTypes = {
+export type BucketChangeType = 'M' | '-';
+
+const changeTypes: { [name: string]: BucketChangeType } = {
 	MODIFY: 'M',
-	REMOVE: '-',
-	ADD: '+'
+	REMOVE: '-'
 };
 
 const { object_diff, transform_object_diff, apply_object_diff } = jsondiff( {list_diff: false} )
@@ -17,32 +20,55 @@ export {
 	apply_diff as apply
 }
 
-function modify( id, version, patch ) {
-	return { o: changeTypes.MODIFY, id: id, ccid: uuid.v4(), v: patch };
+function modify( id: string, version: number, patch: {} ) {
+	return { o: changeTypes.MODIFY, id: id, ccid: uuid(), v: patch };
 }
 
-function buildChange( type, id, object, ghost ) {
+function buildChange( type: BucketChangeType, id: string, object: {}, ghost: {| version: number, data: {} |} ) {
 	return buildChangeFromOrigin( type, id, ghost.version, object, ghost.data );
 }
 
-function buildChangeFromOrigin( type, id, version, target, origin ) {
-	var changeData = {
-		o: type,
-		id: id,
-		ccid: uuid.v4()
-	};
+export type ModifyChange = {
+	o: 'M',
+	id: string,
+	ccid: string,
+	v: ObjectOperationSet,
+	sv?: number
+}
 
-	// Remove operations have no source version or diff
-	if ( type === changeTypes.REMOVE ) return changeData;
+export type RemoveChange = {
+	o: '-',
+	id: string,
+	ccid: string
+}
 
-	if ( version > 0 ) changeData.sv = version;
+export type Change = ModifyChange | RemoveChange;
 
-	changeData.v = object_diff( origin, target );
+function buildChangeFromOrigin( type: BucketChangeType, id: string, version: number, target: {}, origin: {} ): Change {
+
+	if ( type === changeTypes.REMOVE ) {
+		return {
+			o: '-',
+			id,
+			ccid: uuid()
+		};
+	}
 
-	return changeData;
+
+	const change: ModifyChange = {
+		o: 'M',
+		id,
+		ccid: uuid(),
+		v: object_diff( origin, target )
+	}
+
+	if ( version > 0 ) {
+		change.sv = version;
+	}
+	return change;
 }
 
-function compressChanges( changes, origin ) {
+function compressChanges( changes: Array<Change>, origin: {} ): ?ObjectOperationSet {
 	var modified;
 
 	if ( changes.length === 0 ) {
@@ -50,13 +76,17 @@ function compressChanges( changes, origin ) {
 	}
 
 	if ( changes.length === 1 ) {
-		return changes[0].v;
+		const change: Change = changes[0];
+		if ( change.o === 'M' ) {
+			return change.v;
+		}
+		return null;
 	}
 
 	modified = changes.reduce( function( from, change ) {
 		// deletes when, any changes after a delete are ignored
 		if ( from === null ) return null;
-		if ( from.o === changeTypes.REMOVE ) return null;
+		if ( change.o === '-' ) return null;
 		return apply_object_diff( from, change.v );
 	}, origin );
 
@@ -65,10 +95,10 @@ function compressChanges( changes, origin ) {
 	return object_diff( origin, modified );
 }
 
-function rebase( local_diff, remote_diff, origin ) {
+function rebase( local_diff: ObjectOperationSet, remote_diff: ObjectOperationSet, origin: {} ) {
 	return transform_object_diff( local_diff, remote_diff, origin );
 }
 
-function apply_diff( patch, object ) {
+function apply_diff( patch: Change, object: {} ) {
 	return apply_object_diff( object, patch );
 }

From edc3d322ab87c64b5eec500daa8d2e9ed9abdac6 Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Wed, 28 Feb 2018 13:46:14 -0800
Subject: [PATCH 6/8] Prevent flow from failing builds

---
 .travis.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index c514343..4503a2e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,11 +1,12 @@
 language: node_js
 sudo: false
 script:
+# Enable flow to have flow errors fail the build
+# - npm -s run flow
 # lint errors fail the build
 - npm -s run lint
 # unit tests with coverage report
 - npm -s run test:coverage
-- npm -s run flow
 node_js:
 - '8'
 - '7'

From fb3cb6f5ec5643a905f2805ac7e432e2d51039a7 Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Wed, 28 Feb 2018 13:46:48 -0800
Subject: [PATCH 7/8] Moves definitions to fix lint errors - fixes some
 warnings

---
 src/simperium/channel.js | 192 +++++++++++++++++++--------------------
 1 file changed, 96 insertions(+), 96 deletions(-)

diff --git a/src/simperium/channel.js b/src/simperium/channel.js
index ee248a2..0a8c186 100644
--- a/src/simperium/channel.js
+++ b/src/simperium/channel.js
@@ -10,6 +10,100 @@ import uuid from 'uuid/v4'
 
 const { EventEmitter } = events;
 
+type Ghost = {
+	key: string,
+	version: number,
+	data: {}
+}
+
+/**
+ * A ghost represents a version of a bucket object as known by Simperium
+ *
+ * Generally a client will keep the last known ghost stored locally for efficient
+ * diffing and patching of Simperium change operations.
+ *
+ * @typedef {Object} Ghost
+ * @property {Number} version - the ghost's version
+ * @property {String} key - the simperium bucket object id this ghost is for
+ * @property {Object} data - the data for the given ghost version
+ */
+
+/**
+ * Callback function used by the ghost store to iterate over existing ghosts
+ *
+ * @callback ghostIterator
+ * @param {Ghost} - the current ghost
+ */
+
+/**
+ * A GhostStore provides the store mechanism for ghost data that the Channel
+ * uses to maintain syncing state and producing change operations for
+ * Bucket objects.
+ *
+ * @interface GhostStore
+ */
+interface GhostStore {
+	/**
+	 * Retrieve a Ghost for the given bucket object id
+	 *
+	 * @function
+	 * @name GhostStore#get
+	 * @param {String} id - bucket object id
+	 * @returns {Promise<Ghost>} - the ghost for this object
+	 */
+	get( id: string ): Promise<Ghost>;
+
+	/**
+	 * Save a ghost in the store.
+	 *
+	 * @function
+	 * @name GhostStore#put
+	 * @param {String} id - bucket object id
+	 * @param {Number} version - version of ghost data
+	 * @param {Object} data - object literal to save as this ghost's data for this version
+	 * @returns {Promise<Ghost>} - the ghost for this object
+	 */
+	put( id: string, version: number, data: {} ): Promise<Ghost>;
+
+	/**
+	 * Delete a Ghost from the store.
+	 *
+	 * @function
+	 * @name GhostStore#remove
+	 * @param {String} id - bucket object id
+	 * @returns {Promise<Ghost>} - the ghost for this object
+	 */
+	remove( id: string ): Promise<Ghost>;
+
+	/**
+	 * Iterate over existing Ghost objects with the given callback.
+	 *
+	 * @function
+	 * @name GhostStore#eachGhost
+	 * @param {ghostIterator} - function to run against each ghost
+	 */
+	eachGhost( iterator: ( Ghost ) => void ): void;
+
+	/**
+	 * Get the current change version (cv) that this channel has synced.
+	 *
+	 * @function
+	 * @name GhostStore#getChangeVersion
+	 * @returns {Promise<String>} - the current change version for the bucket
+	 */
+	getChangeVersion(): Promise<string>;
+
+	/**
+	 * Set the current change version.
+	 *
+	 * @function
+	 * @name GhostStore#setChangeVersion
+	 * @param {string} changeVersion - new change version
+	 * @returns {Promise<Void>} - resolves once the change version is saved
+	 */
+	setChangeVersion( changeVersion: string ): Promise<void>;
+}
+
 const jsondiff = new JSONDiff( {list_diff: false} );
 
 type LocalChange = {
@@ -44,12 +138,6 @@ type NetworkChangeErrorResponse = {
 	hasSentFullObject?: boolean
 };
 
-type Ghost = {
-	key: string,
-	version: number,
-	data: {}
-}
-
 class ChangeError extends Error {
 	code: number;
 	changeError: NetworkChangeErrorResponse;
@@ -327,94 +415,6 @@ internal.indexingComplete = function() {
 	this.emit( 'ready' )
 }
 
-/**
- * A ghost represents a version of a bucket object as known by Simperium
- *
- * Generally a client will keep the last known ghost stored locally for efficient
- * diffing and patching of Simperium change operations.
- *
- * @typedef {Object} Ghost
- * @property {Number} version - the ghost's version
- * @property {String} key - the simperium bucket object id this ghost is for
- * @property {Object} data - the data for the given ghost version
- */
-
-/**
- * Callback function used by the ghost store to iterate over existing ghosts
- *
- * @callback ghostIterator
- * @param {Ghost} - the current ghost
- */
-
-/**
- * A GhostStore provides the store mechanism for ghost data that the Channel
- * uses to maintain syncing state and producing change operations for
- * Bucket objects.
- *
- * @interface GhostStore
- */
-interface GhostStore {
-	/**
-	 * Retrieve a Ghost for the given bucket object id
-	 *
-	 * @function
-	 * @name GhostStore#get
-	 * @param {String} id - bucket object id
-	 * @returns {Promise<Ghost>} - the ghost for this object
-	 */
-	 get( id: string ): Promise<Ghost>;
-
-	/**
-	 * Save a ghost in the store.
-	 *
-	 * @function
-	 * @name GhostStore#put
-	 * @param {String} id - bucket object id
-	 * @param {Number} version - version of ghost data
-	 * @param {Object} data - object literal to save as this ghost's data for this version
-	 * @returns {Promise<Ghost>} - the ghost for this object
-	 */
-	 put(id: string, version: number, data: {}): Promise<Ghost>;
-
-	/**
-	 * Delete a Ghost from the store.
-	 *
-	 * @function
-	 * @name GhostStore#remove
-	 * @param {String} id - bucket object id
-	 * @returns {Promise<Ghost>} - the ghost for this object
-	 */
-	 remove(id: string): Promise<Ghost>;
-
-	/**
-	 * Iterate over existing Ghost objects with the given callback.
-	 *
-	 * @function
-	 * @name GhostStore#eachGhost
-	 * @param {ghostIterator} - function to run against each ghost
-	 */
-	 eachGhost(iterator: (Ghost) => void): void;
-
-	/**
-	 * Get the current change version (cv) that this channel has synced.
-	 *
-	 * @function
-	 * @name GhostStore#getChangeVersion
-	 * @returns {Promise<String>} - the current change version for the bucket
-	 */
-	 getChangeVersion(): Promise<string>;
-
-	/**
-	 * Set the current change version.
-	 *
-	 * @function
-	 * @name GhostStore#setChangeVersion
-	 * @param {string} changeVersion - new change version
-	 * @returns {Promise<Void>} - resolves once the change version is saved
-	 */
-	 setChangeVersion(changeVersion: string): Promise<void>;
-}
-
 /**
  * Maintains syncing state for a Simperium bucket.
  *
@@ -744,11 +744,11 @@ const asNetworkChange = ( changeMessage: ChangeMessage ): NetworkChange => {
 	}
 
 	if ( ! changeMessage.cv ) {
-		throw new ProtocolError( 'netwock change missing change version (cv)');
+		throw new ProtocolError( 'netwock change missing change version (cv)' );
 	}
 
 	if ( ! changeMessage.id ) {
-		throw new ProtocolError( 'network change missing id');
+		throw new ProtocolError( 'network change missing id' );
 	}
 
 	if ( operation === '-' ) {

From f462d8ffd7c3c492ec6ea1c675de227cf63fce5d Mon Sep 17 00:00:00 2001
From: Robert Collins <beau@collins.pub>
Date: Wed, 28 Feb 2018 13:50:09 -0800
Subject: [PATCH 8/8] Moves type definiton below relevant comment

---
 src/simperium/channel.js | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/simperium/channel.js b/src/simperium/channel.js
index 0a8c186..e4aa1e4 100644
--- a/src/simperium/channel.js
+++ b/src/simperium/channel.js
@@ -10,12 +10,6 @@ import uuid from 'uuid/v4'
 
 const { EventEmitter } = events;
 
-type Ghost = {
-	key: string,
-	version: number,
-	data: {}
-}
-
 /**
  * A ghost represents a version of a bucket object as known by Simperium
  *
@@ -27,6 +21,11 @@ type Ghost = {
  * @property {String} key - the simperium bucket object id this ghost is for
  * @property {Object} data - the data for the given ghost version
  */
+type Ghost = {
+	key: string,
+	version: number,
+	data: {}
+}
 
 /**
  * Callback function used by the ghost store to iterate over existing ghosts