fix(attachments): When downloads fail, don't resolve to chained actions

Summary: Fixes Sentry 3319 and 3303

Test Plan: Run three new tests

Reviewers: dillon, evan

Reviewed By: dillon, evan

Differential Revision: https://phab.nylas.com/D2118

spec/stores/file-download-store-spec.coffee

@@ -42,6 +42,15 @@ describe "FileDownloadStore", ->
     spyOn(shell, 'showItemInFolder')
     spyOn(shell, 'openItem')
     @testfile = new File(filename: '123.png', contentType: 'image/png', id: "id", size: 100)
+    @testdownload = new Download({
+      state : 'unknown',
+      fileId : 'id',
+      percent : 0,
+      filename : '123.png',
+      filesize : 100,
+      targetPath : '/Users/testuser/.nylas/downloads/id/123.png'
+    })
+
     FileDownloadStore._downloads = {}
     FileDownloadStore._downloadDirectory = "/Users/testuser/.nylas/downloads"
 
@@ -83,24 +92,24 @@ describe "FileDownloadStore", ->
         FileDownloadStore._checkForDownloadedFile(f).then (downloaded) ->
           expect(downloaded).toBe(false)
 
-  describe "_startDownload", ->
+  describe "_runDownload", ->
     beforeEach ->
-      spyOn(FileDownloadStore.Download.prototype, 'run').andCallFake -> Promise.resolve()
+      spyOn(FileDownloadStore.Download.prototype, 'run').andCallFake -> Promise.resolve(@)
       spyOn(FileDownloadStore, '_prepareFolder').andCallFake -> Promise.resolve(true)
       spyOn(FileDownloadStore, '_cleanupDownload')
 
     it "should make sure that the download file path exists", ->
-      FileDownloadStore._startDownload(@testfile)
+      FileDownloadStore._runDownload(@testfile)
       expect(FileDownloadStore._prepareFolder).toHaveBeenCalled()
 
     it "should return the promise returned by download.run if the download already exists", ->
       existing =
         fileId: @testfile.id
         run: jasmine.createSpy('existing.run').andCallFake ->
-          Promise.resolve(true)
+          Promise.resolve(existing)
       FileDownloadStore._downloads[@testfile.id] = existing
 
-      promise = FileDownloadStore._startDownload(@testfile)
+      promise = FileDownloadStore._runDownload(@testfile)
       expect(promise instanceof Promise).toBe(true)
       waitsForPromise ->
         promise.then ->
@@ -113,7 +122,7 @@ describe "FileDownloadStore", ->
 
       it "should resolve with a Download without calling download.run", ->
         waitsForPromise =>
-          FileDownloadStore._startDownload(@testfile).then (download) ->
+          FileDownloadStore._runDownload(@testfile).then (download) ->
             expect(FileDownloadStore.Download.prototype.run).not.toHaveBeenCalled()
             expect(download instanceof FileDownloadStore.Download).toBe(true)
             expect(download.data()).toEqual({
@@ -131,7 +140,7 @@ describe "FileDownloadStore", ->
           Promise.resolve(false)
 
       it "should register the download with the right attributes", ->
-        FileDownloadStore._startDownload(@testfile)
+        FileDownloadStore._runDownload(@testfile)
         advanceClock(0)
         expect(FileDownloadStore.downloadDataForFile(@testfile.id)).toEqual({
           state : 'unstarted',fileId : 'id',
@@ -143,13 +152,13 @@ describe "FileDownloadStore", ->
 
       it "should call download.run", ->
         waitsForPromise =>
-          FileDownloadStore._startDownload(@testfile)
+          FileDownloadStore._runDownload(@testfile)
         runs ->
           expect(FileDownloadStore.Download.prototype.run).toHaveBeenCalled()
 
       it "should resolve with a Download", ->
         waitsForPromise =>
-          FileDownloadStore._startDownload(@testfile).then (download) ->
+          FileDownloadStore._runDownload(@testfile).then (download) ->
             expect(download instanceof FileDownloadStore.Download).toBe(true)
             expect(download.data()).toEqual({
               state : 'unstarted',
@@ -162,9 +171,17 @@ describe "FileDownloadStore", ->
 
   describe "_fetch", ->
     it "should call through to startDownload", ->
-      spyOn(FileDownloadStore, '_startDownload')
+      spyOn(FileDownloadStore, '_runDownload').andCallFake ->
+        Promise.resolve(@testdownload)
       FileDownloadStore._fetch(@testfile)
-      expect(FileDownloadStore._startDownload).toHaveBeenCalled()
+      expect(FileDownloadStore._runDownload).toHaveBeenCalled()
+
+    it "should fail silently since it's called passively", ->
+      spyOn(FileDownloadStore, '_presentError')
+      spyOn(FileDownloadStore, '_runDownload').andCallFake =>
+        Promise.reject(@testdownload)
+      FileDownloadStore._fetch(@testfile)
+      expect(FileDownloadStore._presentError).not.toHaveBeenCalled()
 
   describe "_fetchAndOpen", ->
     it "should open the file once it's been downloaded", ->
@@ -172,7 +189,7 @@ describe "FileDownloadStore", ->
       download = {targetPath: @savePath}
       downloadResolve = null
 
-      spyOn(FileDownloadStore, '_startDownload').andCallFake =>
+      spyOn(FileDownloadStore, '_runDownload').andCallFake =>
         new Promise (resolve, reject) ->
           downloadResolve = resolve
 
@@ -182,17 +199,25 @@ describe "FileDownloadStore", ->
       advanceClock(100)
       expect(shell.openItem).toHaveBeenCalledWith(@savePath)
 
+    it "should open an error if the download fails", ->
+      spyOn(FileDownloadStore, '_presentError')
+      spyOn(FileDownloadStore, '_runDownload').andCallFake =>
+        Promise.reject(@testdownload)
+      FileDownloadStore._fetchAndOpen(@testfile)
+      advanceClock(1)
+      expect(FileDownloadStore._presentError).toHaveBeenCalled()
+
   describe "_fetchAndSave", ->
     beforeEach ->
       @savePath = "/Users/imaginary/.nylas/Downloads/b.png"
       spyOn(atom, 'showSaveDialog').andCallFake (options, callback) => callback(@savePath)
 
     it "should open a save dialog and prompt the user to choose a download path", ->
-      spyOn(FileDownloadStore, '_startDownload').andCallFake =>
+      spyOn(FileDownloadStore, '_runDownload').andCallFake =>
         new Promise (resolve, reject) -> # never resolve
       FileDownloadStore._fetchAndSave(@testfile)
       expect(atom.showSaveDialog).toHaveBeenCalled()
-      expect(FileDownloadStore._startDownload).toHaveBeenCalledWith(@testfile)
+      expect(FileDownloadStore._runDownload).toHaveBeenCalledWith(@testfile)
 
     it "should copy the file to the download path after it's been downloaded and open it after the stream has ended", ->
       download = {targetPath: @savePath}
@@ -202,7 +227,7 @@ describe "FileDownloadStore", ->
         on: (eventName, eventCallback) =>
           onEndEventCallback = eventCallback
 
-      spyOn(FileDownloadStore, '_startDownload').andCallFake =>
+      spyOn(FileDownloadStore, '_runDownload').andCallFake =>
         Promise.resolve(download)
       spyOn(fs, 'createReadStream').andReturn(streamStub)
       spyOn(fs, 'createWriteStream')
@@ -215,6 +240,14 @@ describe "FileDownloadStore", ->
       advanceClock(1)
       expect(shell.showItemInFolder).toHaveBeenCalledWith(download.targetPath)
 
+    it "should open an error if the download fails", ->
+      spyOn(FileDownloadStore, '_presentError')
+      spyOn(FileDownloadStore, '_runDownload').andCallFake =>
+        Promise.reject(@testdownload)
+      FileDownloadStore._fetchAndSave(@testfile)
+      advanceClock(1)
+      expect(FileDownloadStore._presentError).toHaveBeenCalled()
+
   describe "_abortFetchFile", ->
     beforeEach ->
       @download =

src/flux/stores/file-download-store.coffee

@@ -152,7 +152,7 @@ FileDownloadStore = Reflux.createStore
 
   # Returns a promise with a Download object, allowing other actions to be
   # daisy-chained to the end of the download operation.
-  _startDownload: (file) ->
+  _runDownload: (file) ->
     @_prepareFolder(file).then =>
       targetPath = @pathForFile(file)
 
@@ -172,18 +172,16 @@ FileDownloadStore = Reflux.createStore
       # Do we actually need to queue and run the download? Queuing a download
       # for an already-downloaded file has side-effects, like making the UI
       # flicker briefly.
-      @_checkForDownloadedFile(file).then (downloaded) =>
+      @_checkForDownloadedFile(file).then (alreadyHaveFile) =>
-        if downloaded
+        if alreadyHaveFile
           # If we have the file, just resolve with a resolved download representing the file.
           download.promise = Promise.resolve()
           return Promise.resolve(download)
         else
-          cleanup = =>
-            @_cleanupDownload(download)
-            Promise.resolve(download)
           @_downloads[file.id] = download
           @trigger()
-          return download.run().catch(cleanup).then(cleanup)
+          return download.run().finally =>
+            @_cleanupDownload(download)
 
   # Returns a promise that resolves with true or false. True if the file has
   # been downloaded, false if it should be downloaded.
@@ -203,20 +201,25 @@ FileDownloadStore = Reflux.createStore
       mkdirpAsync(targetFolder)
 
   _fetch: (file) ->
-    @_startDownload(file)
+    @_runDownload(file).catch ->
+      # Passively ignore
 
   _fetchAndOpen: (file) ->
-    @_startDownload(file).then (download) ->
+    @_runDownload(file).then (download) ->
       shell.openItem(download.targetPath)
+    .catch =>
+      @_presentError(file)
 
   _fetchAndSave: (file) ->
     atom.showSaveDialog @_defaultSavePath(file), (savePath) =>
       return unless savePath
-      @_startDownload(file).then (download) ->
+      @_runDownload(file).then (download) ->
         stream = fs.createReadStream(download.targetPath)
         stream.pipe(fs.createWriteStream(savePath))
         stream.on 'end', ->
           shell.showItemInFolder(savePath)
+      .catch =>
+        @_presentError(file)
 
   _abortFetchFile: (file) ->
     download = @_downloads[file.id]
@@ -243,5 +246,14 @@ FileDownloadStore = Reflux.createStore
 
     path.join(downloadDir, file.displayName())
 
+  _presentError: (file) ->
+    dialog = require('remote').require('dialog')
+    dialog.showMessageBox
+      type: 'warning'
+      message: "Download Failed"
+      detail: "Unable to download #{file.displayName()}.
+               Check your network connection and try again."
+      buttons: ["OK"]
+
 # Expose the Download class for our tests, and possibly for other things someday
 FileDownloadStore.Download = Download