No Handler for Event viewId when view id or state data has new line character

[hezhenxing]

This is a very strange problem, when the data type for View id or state is a list of Text, and the data contains new line character, calling any update handler will result in an error similar to this:

No Handler for Event viewId: Message ["\n"] action: Edit d1c8ab99-45b3-4dad-8a5a-f50563ab9ebd

Here is a snippet of the code:

page :: Page es '[Message]
page = do
  works <- allWorks
  pure $ layout Works $ do
    hyper (Message ["\n"]) $ homeView

data Message = Message [Text]
  deriving (Generic, ViewId)

instance HyperView Message es where
  data Action Message = Hello

  update Hello = do
    pure $ helloView

[seanhess]

Good catch! Let's create a test for this too.

Can I ask why one might use a list in a ViewId? I can definitely see it coming up with state, but I can't imagine a use-case for a list in a view id.

[hezhenxing]

My use case is not using a list in ViewId, but in ViewState, but the problem is the same.