Handle cases where sync storage is not available. Fix #406.

omega-target-chromium-extension/background.coffee

@@ -138,11 +138,12 @@ actionForUrl = (url) ->
 storage = new OmegaTargetCurrent.Storage(chrome.storage.local, 'local')
 state = new OmegaTargetCurrent.BrowserStorage(localStorage, 'omega.local.')
 
-syncStorage = new OmegaTargetCurrent.Storage(chrome.storage.sync, 'sync')
-sync = new OmegaTargetCurrent.OptionsSync(syncStorage)
-if localStorage['omega.local.syncOptions'] != '"sync"'
-  sync.enabled = false
-sync.transformValue = OmegaTargetCurrent.Options.transformValueForSync
+if chrome.storage.sync
+  syncStorage = new OmegaTargetCurrent.Storage(chrome.storage.sync, 'sync')
+  sync = new OmegaTargetCurrent.OptionsSync(syncStorage)
+  if localStorage['omega.local.syncOptions'] != '"sync"'
+    sync.enabled = false
+  sync.transformValue = OmegaTargetCurrent.Options.transformValueForSync
 
 options = new OmegaTargetCurrent.Options(null, storage, state, Log, sync)
 options.externalApi = new OmegaTargetCurrent.ExternalApi(options)

omega-target-chromium-extension/src/storage.coffee

@@ -24,6 +24,10 @@ class ChromeStorage extends OmegaTarget.Storage
         err = new OmegaTarget.Storage.RateLimitExceededError()
         err.perMinute = true
         err.sustained = 10
+      else if err.message.indexOf('is not available') >= 0
+        # This could happen if the storage area is not available. For example,
+        # some Chromium-based browsers disable access to the sync storage.
+        err = new OmegaTarget.Storage.StorageUnavailableError()
 
     return Promise.reject(err)
 

omega-target/src/options.coffee

@@ -89,7 +89,14 @@ class Options
       else
         @_state.set({'syncOptions': 'sync'})
         @_syncWatchStop = @sync.watchAndPull(@_storage)
-        @sync.copyTo(@_storage).then =>
+        @sync.copyTo(@_storage).catch(Storage.StorageUnavailableError, =>
+          console.error('Warning: Sync storage is not available in this ' +
+            'browser! Disabling options sync.')
+          @_syncWatchStop?()
+          @_syncWatchStop = null
+          @sync = null
+          @_state.set({'syncOptions': 'unsupported'})
+        ).then =>
           @_storage.get(null)
 
     @optionsLoaded = loadRaw.then((options) =>

omega-target/src/storage.coffee

@@ -19,6 +19,17 @@ class Storage
     class QuotaExceededError extends Error
       constructor: -> super
 
+  ###*
+  # If this storage is not available for some reason, all operations should
+  # reject with an instance of StorageUnavailableError, when implemented in
+  # derived classes of Storage.
+  # This error is considered fatal and unrecoverable in the current environment.
+  # Further access to this storage should be avoided until restart.
+  ###
+  @StorageUnavailableError:
+    class StorageUnavailableError extends Error
+      constructor: -> super
+
   ###*
   # A set of operations to be performed on a Storage.
   # @typedef WriteOperations