Feature request: Add ProgramTest.ensurePageChange

[jfmengels]

There is a expectPageChange function in the API, but there is no ensurePageChange.

Context

We would like to have a test that asserts the flow of multiple pages, and the flow includes a click on a link.

-- ...
  |> ProgramTest.clickLink "Text" "href"
  |> ProgramTest.ensurePageChange "/href"
  -- do more assertions once the page has changed

Is there a limitation in the framework to do this, or is it counter to the philosophy of the tool?

[avh4]

ensurePageChange is meant for when you clicked a link that your app doesn't handle, so the browser is handling it and navigating you to a new URL, so this would correspond to the Elm app being destroyed!

• Are you testing a SPA where your app handled the link click? If so, then you want ensureBrowserUrl / expectBrowserUrl instead.
• Is it a link that opens the URL in a new window/tab in the real app? If so, then that's not really implemented yet, see clickLink onClick validation should not trigger when target="_blank" #90 though I'm not 100% how the API should actually work for that case w/r to checking that the new window/tab was opened.
• If you just want to check that the link is there and then continue in the test, I personally might just ensureViewHas [ tag "a", attribute (href "href"), containing [ text "Text" ]
• ... or if you really want to check clicking the link, I'd probably do

      |> Expect.all
          [ ProgramTest.clickLink "Text" "href"
              >> ProgramTest.ensurePageChange "/href"
          , ... more stuff ...
          ]

• Or did I miss something? What's the real-world sequence of events you're trying to write a test for? Is the Elm app still running after you click that link?