watcher resyncs on cleared index, ref #31

src/watcher.coffee

@@ -59,10 +59,18 @@ class Watcher extends EventEmitter
     @emit 'error', error
     @_retry()
 
+  _resync: (err) =>
+    @index = err.error.index
+    @retryAttempts = 0
+    @emit 'resync', err
+    @_watch()
+
   _respHandler: (err, val, headers) =>
     return if @stopped
 
-    if err
+    if err?.errorCode is 401 and err.error?.index?
+      @_resync err
+    else if err
       @_error err
     else if headers?['x-etcd-index']? and not val?
       @_missingValue headers

test/watcher.coffee

@@ -1,4 +1,7 @@
-require 'should'
+should = require 'should'
+nock = require 'nock'
+
+Etcd = require '../src/index'
 Watcher = require '../src/watcher.coffee'
 
 class FakeEtcd
@@ -121,3 +124,45 @@ describe 'Watcher', ->
     w.stop()
 
 
+describe 'Watcher resync', ->
+
+  getNock = ->
+    nock 'http://127.0.0.1:4001'
+
+  it 'should resync if index is outdated and cleared', (done) ->
+    # getNock()
+    #   .get('/v2/keys/key')
+    #   .reply(200, {})
+
+    getNock()
+      .get('/v2/keys/key?waitIndex=0&wait=true')
+      .reply(401, {
+        errorCode: 401,
+        message: "The event in requested index is outdated and cleared",
+        cause: "the requested history has been cleared [1007/4]",
+        index: 2006
+        })
+      .get('/v2/keys/key?waitIndex=2006&wait=true')
+        .reply(200, {
+          action:"set",
+          node: {
+            key: "/key",
+            value: "banan",
+            modifiedIndex: 2013,
+            createdIndex: 2013
+            },
+          prevNode: {
+            key: "/key",
+            value: "2",
+            modifiedIndex: 5,
+            createdIndex: 5
+            }
+          })
+
+    etcd = new Etcd
+    w = etcd.watcher 'key', 0
+    w.on 'change', (res) ->
+      res.node.value.should.equal 'banan'
+      done()
+
+  it 'should discover if it missed any updates on resync'