Add error handling when file is deleted while watching

src/tail.coffee

@@ -43,7 +43,12 @@ class Tail extends events.EventEmitter
   watch: (pos) ->
     return if @isWatching
     @isWatching = true
-    stats =  fs.statSync(@filename)
+    try
+      stats =  fs.statSync(@filename)
+    catch err
+      @logger.error("watch for #{@filename} failed: #{@err}") if @logger
+      @emit("error", "watch for #{@filename} failed: #{@err}")
+      return
     @pos = if pos? then pos else stats.size  
 
     if @logger
@@ -59,7 +64,12 @@ class Tail extends events.EventEmitter
 
   watchEvent: (e) ->
     if e is 'change'
-      stats = fs.statSync(@filename)
+      try
+        stats = fs.statSync(@filename)
+      catch err
+        @logger.error("'change' event for #{@filename}. #{@err}") if @logger
+        @emit("error", "'change' event for #{@filename}. #{@err}")
+        return
       @pos = stats.size if stats.size < @pos #scenario where texts is not appended but it's actually a w+
       if stats.size > @pos
         @queue.push({start: @pos, end: stats.size})

test/mocha.opts

@@ -1 +1 @@
---compilers mocha --compilers coffee:coffee-script/register
+--compilers mocha --compilers coffee:coffee-script/register --timeout 3000

test/tail.coffee

@@ -60,4 +60,25 @@ describe 'Tail', ->
     for l in lines
       fs.writeSync fd, l+'\n'
 
-    fs.closeSync fd
+    fs.closeSync fd
+
+  it 'should send error event on deletion of file while watching', (done)->
+    text = "This is a line\n"
+
+    fd = fs.openSync fileToTest, 'w+'
+
+    tailedFile = new Tail fileToTest, {fsWatchOptions: {interval:100}, logger: console}
+
+    # ensure error gets called when the file is deleted
+    tailedFile.on 'error', (line) ->
+      # recreate file so that `afterEach` can cleanup
+      fd = fs.openSync fileToTest, 'w+'
+      done()
+
+    tailedFile.on 'line', (line) ->
+      # delete the file
+      fs.unlinkSync fileToTest
+
+    fs.writeSync fd, text
+
+    fs.closeSync fd