live_view_native_test.ex

defmodule LiveViewNativeTest do
  @moduledoc ~S'''
  Conveniences for testing function components as well as
  LiveViews and LiveComponents.

  ## Testing function components

  There are two mechanisms for testing function components. Imagine the
  following component:

      def greet(assigns) do
        ~LVN"""
        <Text>Hello, <%= @name %>!</Text>
        """
      end

  You can test it by using `render_component/3`, passing the function
  reference to the component as first argument:

      import LiveViewNativeTest

      test "greets" do
        assert render_component(&MyComponents.greet/1, name: "Mary") ==
                 "<Text>Hello, Mary!</Text>"
      end

  However, for complex components, often the simplest way to test them
  is by using the `~LVN` sigil itself:

      import LiveViewNative.Component
      import LiveViewNativeTest

      test "greets" do
        assigns = %{}
        assert rendered_to_string(~H"""
               <MyComponents.greet name="Mary" />
               """) ==
                 "<Text>Hello, Mary!</Text>"
      end

  The difference is that we use `rendered_to_string/1` to convert the rendered
  template to a string for testing.

  ## LiveView Native paths and params

  When calling LiveView Native paths for either dead renders or live renders, the path
  that you call in a regular `Phoenix.LiveViewTest` is identical to the path you call in a
  `LiveViewNativeTest`. The `_format` and `_interface` params are used to delegate to the proper
  render components and render functions. The examples throughout this documentation will regularly
  show the use of those two params when calling either `Phoenix.ConnTest.get/3` or `live/3`

  ## Testing LiveViewNative.LiveViews and LiveViewNative.LiveComponents

  In LiveViewNative.LiveComponents and LiveViewNative.LiveView tests, we interact with views
  via process communication in substitution of a client.
  Like a client, our test process receives messages about the
  rendered updates from the view which can be asserted against
  to test the life-cycle and behavior of LiveViewNative.LiveViews and their
  children.

  ### Testing LiveViewNative.LiveViews

  The life-cycle of a LiveViewNative.LiveView as outlined in the `Phoenix.LiveView`
  docs details how a view starts as a stateless markup render in a disconnected
  socket state. Once the browser receives the markup, it connects to the
  server and a new LiveView process is started, remounted in a connected
  socket state, and the view continues statefully. The LiveView test functions
  support testing both disconnected and connected mounts separately, for example:

      import Plug.Conn
      import Phoenix.ConnTest
      import LiveViewNativeTest
      @endpoint MyEndpoint

      test "disconnected and connected mount", %{conn: conn} do
        conn = get(conn, "/my-path", _format: "gameboy")
        assert lvn_response(conn, 200, _format: :gameboy) =~ "<Title>My Disconnected View</Title>"

        {:ok, _view, markup} = live(conn, _format: :gameboy)
        assert markup =~ "<Title>My Connected View</Title>"
      end

      test "redirected mount", %{conn: conn} do
        assert {:error, {:redirect, %{to: "/somewhere"}}} = live(conn, "my-path")
      end

  Here, we start by using the familiar `Phoenix.ConnTest` function, `get/3` to
  test the regular HTTP GET request which invokes mount with a disconnected socket.
  Next, `live/2` is called with our sent connection to mount the view in a connected
  state, which starts our stateful LiveView process.

  In general, it's often more convenient to test the mounting of a view
  in a single step, provided you don't need the result of the stateless HTTP
  render. This is done with a single call to `live/3`, which performs the
  `get` step for us:

      test "connected mount", %{conn: conn} do
        {:ok, _view, markup} = live(conn, "/my-path", _format: :gameboy)
        assert markup =~ "<Title>My Connected View</Title>"
      end

  ### Testing Events

  The client can send a variety of events to a LiveView via `phx-` bindings,
  which are sent to the `handle_event/3` callback. To test events sent by the
  browser and assert on the rendered side effect of the event, use the
  `render_*` functions:

    * `render_click/1` - sends a phx-click event and value, returning
      the rendered result of the `handle_event/3` callback.

    * `render_focus/2` - sends a phx-focus event and value, returning
      the rendered result of the `handle_event/3` callback.

    * `render_blur/1` - sends a phx-blur event and value, returning
      the rendered result of the `handle_event/3` callback.

    * `render_submit/1` - sends a form phx-submit event and value, returning
      the rendered result of the `handle_event/3` callback.

    * `render_change/1` - sends a form phx-change event and value, returning
      the rendered result of the `handle_event/3` callback.

    * `render_keydown/1` - sends a form phx-keydown event and value, returning
      the rendered result of the `handle_event/3` callback.

    * `render_keyup/1` - sends a form phx-keyup event and value, returning
      the rendered result of the `handle_event/3` callback.

    * `render_hook/3` - sends a hook event and value, returning
      the rendered result of the `handle_event/3` callback.

  For example:

      {:ok, view, _markup} = live(conn, "/thermo", _format: :gameboy)

      assert view
             |> element("button#inc")
             |> render_click() =~ "The temperature is: 31℉"

  In the example above, we are looking for a particular element on the page
  and triggering its phx-click event. LiveView takes care of making sure the
  element has a phx-click and automatically sends its values to the server.

  You can also bypass the element lookup and directly trigger the LiveView
  event in most functions:

      assert render_click(view, :inc, %{}) =~ "The temperature is: 31℉"

  The `element` style is preferred as much as possible, as it helps LiveView
  perform validations and ensure the events in the markup actually matches the
  event names on the server.

  ### Testing regular messages

  LiveViews are `GenServer`'s under the hood, and can send and receive messages
  just like any other server. To test the side effects of sending or receiving
  messages, simply message the view and use the `render` function to test the
  result:

      send(view.pid, {:set_temp, 50})
      assert render(view) =~ "The temperature is: 50℉"

  ### Testing LiveViewNative.LiveComponents

  LiveViewNative.LiveComponents can be tested in two ways. One way is to use the same
  `render_component/2` function as function components. This will mount
  the LiveComponent and render it once, without testing any of its events:

      assert render_component(MyComponent, id: 123, user: %User{}) =~
               "some markup in component"

  However, if you want to test how components are mounted by a LiveView
  and interact with ViewTree events, you must use the regular `live/3` macro
  to build the LiveView with the component and then scope events by
  passing the view and a **ViewTree selector** in a list:

      {:ok, view, _markup} = live(conn, "/users", _format: :gameboy)
      markup = view |> element("#user-13 a", "Delete") |> render_click()
      refute markup =~ "user-13"
      refute view |> element("#user-13") |> has_element?()

  In the example above, LiveView will lookup for an element with
  ID=user-13 and retrieve its `phx-target`. If `phx-target` points
  to a component, that will be the component used, otherwise it will
  fallback to the view.
  '''

  @flash_cookie "__phoenix_flash__"

  require Phoenix.ConnTest
  require Phoenix.ChannelTest

  alias Phoenix.LiveView.{Diff, Socket}
  alias LiveViewNativeTest.{ClientProxy, ViewTree, Element, View, Upload, UploadClient}

  @doc """
  Puts connect params to be used on LiveView connections.

  See `Phoenix.LiveView.get_connect_params/1`.
  """
  def put_connect_params(conn, params) when is_map(params) do
    Plug.Conn.put_private(conn, :live_view_connect_params, params)
  end

  @doc """
  Spawns a connected LiveView process.

  If a `path` is given, then a regular `get(conn, path, params)`
  is done and the page is upgraded to a LiveView. If
  no path is given, it assumes a previously rendered
  `%Plug.Conn{}` is given, which will be converted to
  a LiveView immediately.

  ## Examples

      {:ok, view, markup} = live(conn, "/path", _fromat: :gameboy)
      assert view.module == MyLive
      assert markup =~ "the count is 3"

      assert {:error, {:redirect, %{to: "/somewhere"}}} = live(conn, "/path", _format: :gameboy)

  """
  defmacro live(conn, path \\ nil, params \\ []) do
    quote bind_quoted: binding(), generated: true do
      {path, params} = if (is_list(path) && params == []) do
        {nil, path}
      else
        {path, params}
      end

      params =
        params
        |> Keyword.put_new(:_format, :html)
        |> Keyword.take([:_format, :_interface])
        |> Enum.into(%{}, fn
          {:_format, value} -> {"_format", LiveViewNative.Utils.stringify(value)}
          {:_interface, value} -> {"_interface", value}
        end)

      conn = Phoenix.LiveViewTest.put_connect_params(conn, params)

      cond do
        is_binary(path) ->
          uri = URI.parse(path)

          params = Map.merge(
            (Map.get(uri, :query) || "") |> URI.decode_query(),
            params
          )

          path = %URI{
            path: path,
            query: Plug.Conn.Query.encode(params)
          }
          |> URI.to_string()

          LiveViewNativeTest.__live__(get(conn, path), path)

        is_nil(path) ->
          LiveViewNativeTest.__live__(conn)

        true ->
          raise RuntimeError, "path must be nil or a binary, got: #{inspect(path)}"
      end
    end
  end

  @doc """
  Spawns a connected LiveView process mounted in isolation as the sole rendered element.

  Useful for testing LiveViews that are not directly routable, such as those
  built as small components to be re-used in multiple parents. Testing routable
  LiveViews is still recommended whenever possible since features such as
  live navigation require routable LiveViews.

  ## Options

    * `:session` - the session to be given to the LiveView
    * `:_format` - the format of the client connecting
    * `:_interface` - a map of interface state values from the client

  All other options are forwarded to the LiveView for rendering. Refer to
  `Phoenix.Component.live_render/3` for a list of supported render
  options.

  ## Examples

      {:ok, view, markup} =
        live_isolated(conn, MyAppWeb.ClockLive, session: %{"tz" => "EST"})

  Use `put_connect_params/2` to put connect params for a call to
  `Phoenix.LiveView.get_connect_params/1` in `c:Phoenix.LiveView.mount/3`:

      {:ok, view, html} =
        conn
        |> put_connect_params(%{"param" => "value"})
        |> live_isolated(AppWeb.ClockLive, session: %{"tz" => "EST"}, _format: :gameboy)


  """
  defmacro live_isolated(conn, live_view, opts \\ []) do
    endpoint = Module.get_attribute(__CALLER__.module, :endpoint)

    params =
      opts
      |> Keyword.take([:_format, :_interface])
      |> Enum.into(%{}, fn
        {:_format, value} -> {"_format", LiveViewNative.Utils.stringify(value)}
        {:_interface, value} -> {"_interface", value}
      end)
      |> Macro.escape()

    quote bind_quoted: binding(), unquote: true do
      unquote(__MODULE__).__isolated__(put_connect_params(conn, params), endpoint, live_view, opts)
    end
  end

  @doc false
  def __isolated__(conn, endpoint, live_view, opts) do
    put_in(conn.private[:phoenix_endpoint], endpoint || raise("no @endpoint set in test module"))
    |> Plug.Test.init_test_session(%{})
    |> Phoenix.LiveView.Router.fetch_live_flash([])
    |> Phoenix.LiveView.Controller.live_render(live_view, opts)
    |> connect_from_static_token(nil)
  end

  @doc false
  def __live__(%Plug.Conn{state: state, status: status} = conn) do
    path = rebuild_path(conn)

    case {state, status} do
      {:sent, 200} ->
        connect_from_static_token(conn, path)

      {:sent, 302} ->
        error_redirect_conn(conn)

      {:sent, _} ->
        raise ArgumentError,
              "request to #{conn.request_path} received unexpected #{status} response"

      {_, _} ->
        raise ArgumentError, """
        a request has not yet been sent.

        live/1 must use a connection with a sent response. Either call get/3
        prior to live/2, or use live/3 while providing a path to have a get
        request issued for you. For example issuing a get yourself:

            {:ok, view, _body} =
              conn
              |> get("#{path}")
              |> live(_format: :gameboy)

        or performing the GET and live connect in a single step:

            {:ok, view, _body} = live(conn, "#{path}", _format: :gameboy)
        """
    end
  end

  @doc false
  def __live__(conn, path) do
    connect_from_static_token(conn, path)
  end

  defp connect_from_static_token(
         %Plug.Conn{status: 200, assigns: %{live_module: live_module}} = conn,
         path
       ) do
    ViewTree.ensure_loaded!()

    router =
      try do
        Phoenix.Controller.router_module(conn)
      rescue
        KeyError -> nil
      end

    start_proxy(path, %{
      response: Phoenix.ConnTest.response(conn, 200),
      connect_params: conn.private[:live_view_connect_params] || %{},
      connect_info: conn.private[:live_view_connect_info] || prune_conn(conn) || %{},
      live_module: live_module,
      router: router,
      endpoint: Phoenix.Controller.endpoint_module(conn),
      session: maybe_get_session(conn),
      url: Plug.Conn.request_url(conn)
    })
  end

  defp connect_from_static_token(%Plug.Conn{status: 200}, _path) do
    {:error, :nosession}
  end

  defp connect_from_static_token(%Plug.Conn{status: redir} = conn, _path)
       when redir in [301, 302] do
    error_redirect_conn(conn)
  end

  defp prune_conn(conn) do
    %{conn | resp_body: nil, resp_headers: []}
  end

  defp error_redirect_conn(conn) do
    to = hd(Plug.Conn.get_resp_header(conn, "location"))

    opts =
      if flash = conn.assigns[:flash] || conn.private[:phoenix_flash] do
        %{to: to, flash: flash}
      else
        %{to: to}
      end

    {:error, {error_redirect_key(conn), opts}}
  end

  defp error_redirect_key(%{private: %{phoenix_live_redirect: true}}), do: :live_redirect
  defp error_redirect_key(_), do: :redirect

  defp start_proxy(path, %{} = opts) do
    ref = make_ref()

    %{"_format" => format} = opts.connect_params

    %{test_client: client} = LiveViewNative.fetch_plugin!(format)

    opts =
      Map.merge(opts, %{
        caller: {self(), ref},
        body: opts.response,
        client: client,
        connect_params: opts.connect_params,
        connect_info: opts.connect_info,
        live_module: opts.live_module,
        endpoint: opts.endpoint,
        session: opts.session,
        url: opts.url,
        test_supervisor: fetch_test_supervisor!()
      })

    case ClientProxy.start_link(opts) do
      {:ok, _} ->
        receive do
          {^ref, {:ok, view, body}} -> {:ok, view, body}
        end

      {:error, reason} ->
        exit({reason, {__MODULE__, :live, [path]}})

      :ignore ->
        receive do
          {^ref, {:error, reason}} -> {:error, reason}
        end
    end
  end

  defp fetch_test_supervisor!() do
    case ExUnit.fetch_test_supervisor() do
      {:ok, sup} -> sup
      :error -> raise ArgumentError, "LiveView helpers can only be invoked from the test process"
    end
  end

  defp maybe_get_session(%Plug.Conn{} = conn) do
    try do
      Plug.Conn.get_session(conn)
    rescue
      _ -> %{}
    end
  end

  defp rebuild_path(%Plug.Conn{request_path: request_path, query_string: ""}),
    do: request_path

  defp rebuild_path(%Plug.Conn{request_path: request_path, query_string: query_string}),
    do: request_path <> "?" <> query_string

  @doc """
  Renders a component.

  The first argument may either be a function component, as an
  anonymous function:

      assert render_component(&Weather.city/1, name: "Kraków") =~
               "some markup in component"

  Or a stateful component as a module. In this case, this function
  will mount, update, and render the component. The `:id` option is
  a required argument:

      assert render_component(MyComponent, id: 123, user: %User{}) =~
               "some markup in component"

  If your component is using the router, you can pass it as argument:

      assert render_component(MyComponent, %{id: 123, user: %User{}}, router: SomeRouter) =~
               "some markup in component"

  """
  defmacro render_component(component, assigns \\ Macro.escape(%{}), opts \\ []) do
    endpoint = Module.get_attribute(__CALLER__.module, :endpoint)

    component =
      if is_atom(component) do
        quote do
          unquote(component).__live__()
          unquote(component)
        end
      else
        component
      end

    quote do
      Phoenix.LiveViewTest.__render_component__(
        unquote(endpoint),
        unquote(component),
        unquote(assigns),
        unquote(opts)
      )
    end
  end

  @doc false
  def __render_component__(endpoint, component, assigns, opts) when is_atom(component) do
    socket = %Socket{endpoint: endpoint, router: opts[:router]}

    assigns = Map.new(assigns)

    # TODO: Make the ID required once we support only stateful module components as live_component
    mount_assigns = if assigns[:id], do: %{myself: %Phoenix.LiveComponent.CID{cid: -1}}, else: %{}

    socket
    |> Diff.component_to_rendered(component, assigns, mount_assigns)
    |> rendered_to_diff_string(socket)
  end

  def __render_component__(endpoint, function, assigns, opts) when is_function(function, 1) do
    socket = %Socket{endpoint: endpoint, router: opts[:router]}

    assigns
    |> Map.new()
    |> Map.put_new(:__changed__, %{})
    |> function.()
    |> rendered_to_diff_string(socket)
  end

  defp rendered_to_diff_string(rendered, socket) do
    {diff, _, _} = Diff.render(socket, rendered, Diff.new_fingerprints(), Diff.new_components())
    diff |> Diff.to_iodata() |> IO.iodata_to_binary()
  end

  @doc ~S'''
  Converts a rendered template to a string.

  ## Examples

      import LiveViewNative.Component
      import LiveViewNativeTest

      test "greets" do
        assigns = %{}
        assert rendered_to_string(~LVN"""
               <MyComponents.greet name="Mary" />
               """) ==
                 "<Text>Hello, Mary!</Text>"
      end

  '''
  def rendered_to_string(rendered) do
    rendered
    |> Phoenix.HTML.html_escape()
    |> Phoenix.HTML.safe_to_string()
  end

  @doc """
  Sends a click event given by `element` and returns the rendered result.

  The `element` is created with `element/3` and must point to a single
  element on the page with a `phx-click` attribute in it. The event name
  given set on `phx-click` is then sent to the appropriate LiveView
  (or component if `phx-target` is set accordingly). All `phx-value-*`
  entries in the element are sent as values. Extra values can be given
  with the `value` argument.

  If the element does not have a `phx-click` attribute but it is
  a link (the `<a>` tag), the link will be followed accordingly:

    * if the link is a `patch`, the current view will be patched
    * if the link is a `navigate`, this function will return
      `{:error, {:live_redirect, %{to: url}}}`, which can be followed
      with `follow_redirect/2`
    * if the link is a regular link, this function will return
      `{:error, {:redirect, %{to: url}}}`, which can be followed
      with `follow_redirect/2`

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)

      assert view
             |> element("button", "Increment")
             |> render_click() =~ "The temperature is: 30℉"
  """
  def render_click(element, value \\ %{})
  def render_click(%Element{} = element, value), do: render_event(element, :click, value)
  def render_click(view, event), do: render_click(view, event, %{})

  @doc """
  Sends a click `event` to the `view` with `value` and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temperature is: 30℉"
      assert render_click(view, :inc) =~ "The temperature is: 31℉"

  """
  def render_click(view, event, value) do
    render_event(view, :click, event, value)
  end

  @doc """
  Puts the submitter `element_or_selector` on the given `form` element.

  A submitter is an element that initiates the form's submit event on the client. When a submitter
  is put on an element created with `form/3` and then the form is submitted via `render_submit/2`,
  the name/value pair of the submitter will be included in the submit event payload.

  The given element or selector must exist within the form and match one of the following:

  - A `button` or `input` element with `type="submit"`.

  - A `button` element without a `type` attribute.

  ## Examples

      form = view |> form("#my-form")

      assert form
             |> put_submitter("button[name=example]")
             |> render_submit() =~ "Submitted example"
  """
  def put_submitter(form, element_or_selector)

  def put_submitter(%Element{proxy: proxy} = form, submitter) when is_binary(submitter) do
    put_submitter(form, %Element{proxy: proxy, selector: submitter})
  end

  def put_submitter(%Element{} = form, %Element{} = submitter) do
    %{form | meta: Map.put(form.meta, :submitter, submitter)}
  end

  @doc """
  Sends a form submit event given by `element` and returns the rendered result.

  The `element` is created with `element/3` and must point to a single
  element on the page with a `phx-submit` attribute in it. The event name
  given set on `phx-submit` is then sent to the appropriate LiveView
  (or component if `phx-target` is set accordingly). All `phx-value-*`
  entries in the element are sent as values. Extra values, including hidden
  input fields, can be given with the `value` argument.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)

      assert view
             |> element("form")
             |> render_submit(%{deg: 123, avatar: upload}) =~ "123 exceeds limits"

  To submit a form along with some with hidden input values:

      assert view
             |> form("#term", user: %{name: "hello"})
             |> render_submit(%{user: %{"hidden_field" => "example"}}) =~ "Name updated"

  To submit a form by a specific submit element via `put_submitter/2`:

      assert view
             |> form("#term", user: %{name: "hello"})
             |> put_submitter("button[name=example_action]")
             |> render_submit() =~ "Action taken"

  """
  def render_submit(element, value \\ %{})
  def render_submit(%Element{} = element, value), do: render_event(element, :submit, value)
  def render_submit(view, event), do: render_submit(view, event, %{})

  @doc """
  Sends a form submit event to the view and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert render_submit(view, :refresh, %{deg: 32}) =~ "The temp is: 32℉"
  """
  def render_submit(view, event, value) do
    render_event(view, :submit, event, value)
  end

  @doc """
  Sends a form change event given by `element` and returns the rendered result.

  The `element` is created with `element/3` and must point to a single
  element on the page with a `phx-change` attribute in it. The event name
  given set on `phx-change` is then sent to the appropriate LiveView
  (or component if `phx-target` is set accordingly). All `phx-value-*`
  entries in the element are sent as values.

  If you need to pass any extra values or metadata, such as the "_target"
  parameter, you can do so by giving a map under the `value` argument.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)

      assert view
             |> element("form")
             |> render_change(%{deg: 123}) =~ "123 exceeds limits"

      # Passing metadata
      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)

      assert view
             |> element("form")
             |> render_change(%{_target: ["deg"], deg: 123}) =~ "123 exceeds limits"

  As with `render_submit/2`, hidden input field values can be provided like so:

      refute view
            |> form("#term", user: %{name: "hello"})
            |> render_change(%{user: %{"hidden_field" => "example"}}) =~ "can't be blank"

  """
  def render_change(element, value \\ %{})
  def render_change(%Element{} = element, value), do: render_event(element, :change, value)
  def render_change(view, event), do: render_change(view, event, %{})

  @doc """
  Sends a form change event to the view and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert render_change(view, :validate, %{deg: 123}) =~ "123 exceeds limits"
  """
  def render_change(view, event, value) do
    render_event(view, :change, event, value)
  end

  @doc """
  Sends a keydown event given by `element` and returns the rendered result.

  The `element` is created with `element/3` and must point to a single element
  on the page with a `phx-keydown` or `phx-window-keydown` attribute in it.
  The event name given set on `phx-keydown` is then sent to the appropriate
  LiveView (or component if `phx-target` is set accordingly). All `phx-value-*`
  entries in the element are sent as values. Extra values can be given with
  the `value` argument.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert view |> element("#inc") |> render_keydown() =~ "The temp is: 31℉"

  """
  def render_keydown(element, value \\ %{})

  def render_keydown(%Element{} = element, value),
    do: render_event(element, :keydown, value)

  def render_keydown(view, event), do: render_keydown(view, event, %{})

  @doc """
  Sends a keydown event to the view and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert render_keydown(view, :inc) =~ "The temp is: 31℉"

  """
  def render_keydown(view, event, value) do
    render_event(view, :keydown, event, value)
  end

  @doc """
  Sends a keyup event given by `element` and returns the rendered result.

  The `element` is created with `element/3` and must point to a single
  element on the page with a `phx-keyup` or `phx-window-keyup` attribute
  in it. The event name given set on `phx-keyup` is then sent to the
  appropriate LiveView (or component if `phx-target` is set accordingly).
  All `phx-value-*` entries in the element are sent as values. Extra values
  can be given with the `value` argument.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert view |> element("#inc") |> render_keyup() =~ "The temp is: 31℉"

  """
  def render_keyup(element, value \\ %{})
  def render_keyup(%Element{} = element, value), do: render_event(element, :keyup, value)
  def render_keyup(view, event), do: render_keyup(view, event, %{})

  @doc """
  Sends a keyup event to the view and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert render_keyup(view, :inc) =~ "The temp is: 31℉"

  """
  def render_keyup(view, event, value) do
    render_event(view, :keyup, event, value)
  end

  @doc """
  Sends a blur event given by `element` and returns the rendered result.

  The `element` is created with `element/3` and must point to a single
  element on the page with a `phx-blur` attribute in it. The event name
  given set on `phx-blur` is then sent to the appropriate LiveView
  (or component if `phx-target` is set accordingly). All `phx-value-*`
  entries in the element are sent as values. Extra values can be given
  with the `value` argument.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)

      assert view
             |> element("#inactive")
             |> render_blur() =~ "Tap to wake"
  """
  def render_blur(element, value \\ %{})
  def render_blur(%Element{} = element, value), do: render_event(element, :blur, value)
  def render_blur(view, event), do: render_blur(view, event, %{})

  @doc """
  Sends a blur event to the view and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert render_blur(view, :inactive) =~ "Tap to wake"

  """
  def render_blur(view, event, value) do
    render_event(view, :blur, event, value)
  end

  @doc """
  Sends a focus event given by `element` and returns the rendered result.

  The `element` is created with `element/3` and must point to a single
  element on the page with a `phx-focus` attribute in it. The event name
  given set on `phx-focus` is then sent to the appropriate LiveView
  (or component if `phx-target` is set accordingly). All `phx-value-*`
  entries in the element are sent as values. Extra values can be given
  with the `value` argument.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)

      assert view
             |> element("#inactive")
             |> render_focus() =~ "Tap to wake"
  """
  def render_focus(element, value \\ %{})
  def render_focus(%Element{} = element, value), do: render_event(element, :focus, value)
  def render_focus(view, event), do: render_focus(view, event, %{})

  @doc """
  Sends a focus event to the view and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert render_focus(view, :inactive) =~ "Tap to wake"

  """
  def render_focus(view, event, value) do
    render_event(view, :focus, event, value)
  end

  @doc """
  Sends a hook event to the view or an element and returns the rendered result.

  It returns the contents of the whole LiveView or an `{:error, redirect}`
  tuple.

  ## Examples

      {:ok, view, body} = live(conn, "/thermo", _format: :gameboy)
      assert body =~ "The temp is: 30℉"
      assert render_hook(view, :refresh, %{deg: 32}) =~ "The temp is: 32℉"

  If you are pushing events from a hook to a component, then you must pass
  an `element`, created with `element/3`, as first argument and it must point
  to a single element on the page with a `phx-target` attribute in it:

      {:ok, view, _body} = live(conn, "/thermo", _format, :gameboy)
      assert view
             |> element("#thermo-component")
             |> render_hook(:refresh, %{deg: 32}) =~ "The temp is: 32℉"

  """
  def render_hook(view_or_element, event, value \\ %{})

  def render_hook(%Element{} = element, event, value) do
    render_event(%{element | event: to_string(event)}, :hook, value)
  end

  def render_hook(view, event, value) do
    render_event(view, :hook, event, value)
  end

  defp render_event(%Element{} = element, type, value) when is_map(value) or is_list(value) do
    call(element, {:render_event, element, type, value})
  end

  defp render_event(%View{} = view, type, event, value) when is_map(value) or is_list(value) do
    call(view, {:render_event, {proxy_topic(view), to_string(event), view.target}, type, value})
  end

  @doc """
  Awaits all current `assign_async` and `start_async` for a given LiveView or element.

  It renders the LiveView or Element once complete and returns the result.
  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `assert_receive_timeout` (100 ms).

  ## Examples

      {:ok, lv, body} = live(conn, "/path", _format: :gameboy)
      assert body =~ "loading data..."
      assert render_async(lv) =~ "data loaded!"
  """
  def render_async(
        view_or_element,
        timeout \\ Application.fetch_env!(:ex_unit, :assert_receive_timeout)
      ) do
    pids =
      case view_or_element do
        %View{} = view -> call(view, {:async_pids, {proxy_topic(view), nil, nil}})
        %Element{} = element -> call(element, {:async_pids, element})
      end

    timeout_ref = make_ref()
    Process.send_after(self(), {timeout_ref, :timeout}, timeout)

    pids
    |> Enum.map(&Process.monitor(&1))
    |> Enum.each(fn ref ->
      receive do
        {^timeout_ref, :timeout} ->
          raise RuntimeError, "expected async processes to finish within #{timeout}ms"

        {:DOWN, ^ref, :process, _pid, _reason} ->
          :ok
      end
    end)

    if !Process.cancel_timer(timeout_ref) do
      receive do
        {^timeout_ref, :timeout} -> :noop
      after
        0 -> :noop
      end
    end

    render(view_or_element)
  end

  @doc """
  Simulates a `push_patch` to the given `path` and returns the rendered result.
  """
  def render_patch(%View{} = view, path) when is_binary(path) do
    call(view, {:render_patch, proxy_topic(view), path})
  end

  @doc """
  Returns the current list of LiveView children for the `parent` LiveView.

  Children are returned in the order they appear in the rendered template body.

  ## Examples

      {:ok, view, _body} = live(conn, "/thermo", _format: :gameboy)
      assert [clock_view] = live_children(view)
      assert render_click(clock_view, :snooze) =~ "snoozing"
  """
  def live_children(%View{} = parent) do
    call(parent, {:live_children, proxy_topic(parent)})
  end

  @doc """
  Gets the nested LiveView child by `child_id` from the `parent` LiveView.

  ## Examples

      {:ok, view, _body} = live(conn, "/thermo", _format: :gameboy)
      assert clock_view = find_live_child(view, "clock")
      assert render_click(clock_view, :snooze) =~ "snoozing"
  """
  def find_live_child(%View{} = parent, child_id) do
    parent
    |> live_children()
    |> Enum.find(fn %View{id: id} -> id == child_id end)
  end

  @doc """
  Checks if the given element exists on the page.

  ## Examples

      assert view |> element("#some-element") |> has_element?()

  """
  def has_element?(%Element{} = element) do
    call(element, {:render_element, :has_element?, element})
  end

  defguardp is_text_filter(text_filter)
            when is_binary(text_filter) or is_struct(text_filter, Regex) or is_nil(text_filter)

  @doc """
  Checks if the given `selector` with `text_filter` is on `view`.

  See `element/3` for more information.

  ## Examples

      assert has_element?(view, "#some-element")

  """
  def has_element?(%View{} = view, selector, text_filter \\ nil)
      when is_binary(selector) and is_text_filter(text_filter) do
    has_element?(element(view, selector, text_filter))
  end

  @doc """
  Returns the string template body of the rendered view or element.

  If a view is provided, the entire LiveView is rendered.
  If a view after calling `with_target/2` or an element
  are given, only that particular context is returned.

  ## Examples

      {:ok, view, _body} = live(conn, "/thermo", _format: :gameboy)
      assert render(view) =~ ~s|<button id="alarm">Snooze</div>|

      assert view
             |> element("#alarm")
             |> render() == "Snooze"
  """
  def render(view_or_element) do
    view_or_element
    |> coerce_view_or_element()
    |> render_tree()
    |> ViewTree.to_markup()
  end

  defp coerce_view_or_element(%Phoenix.LiveViewTest.View{} = view),
    do: Map.put(view, :__struct__, View)

  defp coerce_view_or_element(%Phoenix.LiveViewTest.Element{} = element),
    do: Map.put(element, :__struct__, Element)

  defp coerce_view_or_element(view_or_element),
    do: view_or_element

  @doc """
  Sets the target of the view for events.

  This emulates `phx-target` directly in tests, without
  having to dispatch the event to a specific element.
  This can be useful for invoking events to one or
  multiple components at the same time:

      view
      |> with_target("#user-1,#user-2")
      |> render_click("Hide", %{})

  """
  def with_target(%View{} = view, target) do
    %{view | target: target}
  end

  defp render_tree(%View{} = view) do
    render_tree(view, {proxy_topic(view), "render", view.target})
  end

  defp render_tree(%Element{} = element) do
    render_tree(element, element)
  end

  defp render_tree(view_or_element, topic_or_element) do
    call(view_or_element, {:render_element, :find_element, topic_or_element})
  end

  defp call(view_or_element, tuple) do
    try do
      GenServer.call(proxy_pid(view_or_element), tuple, :infinity)
    catch
      :exit, {{:shutdown, {kind, opts}}, _} when kind in [:redirect, :live_redirect] ->
        {:error, {kind, opts}}

      :exit, {{exception, stack}, _} ->
        exit({{exception, stack}, {__MODULE__, :call, [view_or_element]}})
    else
      :ok -> :ok
      {:ok, result} -> result
      {:raise, exception} -> raise exception
    end
  end

  @doc """
  Returns an element to scope a function to.

  It expects the current LiveView, a query selector, and a text filter.

  An optional text filter may be given to filter the results by the query
  selector. If the text filter is a string or a regex, it will match any
  element that contains the string (including as a substring) or matches the
  regex.

  So a link containing the text "unopened" will match `element("a", "opened")`.
  To prevent this, a regex could specify that "opened" appear without the prefix "un".
  For example, `element("a", ~r{(?<!un)opened})`.
  But it may be clearer to add an LVN template attribute to make the element easier to
  select.

  After the text filter is applied, only one element must remain, otherwise an
  error is raised.

  If no text filter is given, then the query selector itself must return
  a single element.

      assert view
            |> element("#term > :first-child", "Increment")
            |> render() =~ "Increment</a>"

  Attribute selectors are also supported, and may be used on special cases
  like ids which contain periods:

      assert view
             |> element(~s{[href="/foo"][id="foo.bar.baz"]})
             |> render() =~ "Increment</a>"
  """
  def element(%View{proxy: proxy}, selector, text_filter \\ nil)
      when is_binary(selector) and is_text_filter(text_filter) do
    %Element{proxy: proxy, selector: selector, text_filter: text_filter}
  end

  @doc """
  Returns a form element to scope a function to.

  It expects the current LiveView, a query selector, and the form data.
  The query selector must return a single element.

  The form data will be validated directly against the form markup and
  make sure the data you are changing/submitting actually exists, failing
  otherwise.

  ## Examples

      assert view
            |> form("#term", user: %{name: "hello"})
            |> render_submit() =~ "Name updated"

  This function is meant to mimic what the user can actually do, so you cannot
   set hidden input values. However, hidden values can be given when calling
   `render_submit/2` or `render_change/2`, see their docs for examples.
  """
  def form(%View{proxy: proxy}, selector, form_data \\ %{}) when is_binary(selector) do
    %Element{proxy: proxy, selector: selector, form_data: form_data}
  end

  @doc """
  Builds a file input for testing uploads within a form.

  Given the form ViewTree selector, the upload name, and a list of maps of client metadata
  for the upload, the returned file input can be passed to `render_upload/2`.

  Client metadata takes the following form:

    * `:last_modified` - the last modified timestamp
    * `:name` - the name of the file
    * `:content` - the binary content of the file
    * `:size` - the byte size of the content
    * `:type` - the MIME type of the file
    * `:relative_path` - for simulating webkitdirectory metadata
    * `:meta` - optional metadata sent by the client

  ## Examples

      avatar = file_input(lv, "#my-form-id", :avatar, [%{
        last_modified: 1_594_171_879_000,
        name: "myfile.jpeg",
        content: File.read!("myfile.jpg"),
        size: 1_396_009,
        type: "image/jpeg"
      }])

      assert render_upload(avatar, "myfile.jpeg") =~ "100%"
  """
  defmacro file_input(view, form_selector, name, entries) do
    quote bind_quoted: [view: view, selector: form_selector, name: name, entries: entries] do
      require Phoenix.ChannelTest
      builder = fn -> Phoenix.ChannelTest.connect(Phoenix.LiveView.Socket, %{}) end
      LiveViewNativeTest.__file_input__(view, selector, name, entries, builder)
    end
  end

  @doc false
  def __file_input__(view, selector, name, entries, builder) do
    cid = find_cid!(view, selector)

    for entry <- entries do
      content = entry[:content]
      size = entry[:size]

      if content && size && byte_size(content) != size do
        raise ArgumentError, """
        entry content size must match provided size.

        By default the content size is calculated using byte_size/1, so you
        rarely need to provide the size option yourself unless you are testing
        for misbehaving clients.
        """
      end
    end

    case Phoenix.LiveView.Channel.fetch_upload_config(view.pid, name, cid) do
      {:ok, %{external: false}} ->
        start_upload_client(builder, view, selector, name, entries, cid)

      {:ok, %{external: func}} when is_function(func) ->
        start_external_upload_client(view, selector, name, entries, cid)

      :error ->
        raise "no uploads allowed for #{name}"
    end
  end

  defp find_cid!(view, selector) do
    view_tree = view |> render() |> ViewTree.parse()

    with {:ok, form} <- ViewTree.maybe_one(view_tree, selector) do
      [cid | _] = ViewTree.targets_from_node(view_tree, form)
      cid
    else
      {:error, _reason, msg} -> raise ArgumentError, msg
    end
  end

  defp start_upload_client(builder, view, form_selector, name, entries, cid) do
    {:ok, socket} = builder.()
    spec = {UploadClient, socket: socket, cid: cid}
    {:ok, pid} = Supervisor.start_child(fetch_test_supervisor!(), spec)
    Upload.new(pid, view, form_selector, name, entries, cid)
  end

  defp start_external_upload_client(view, form_selector, name, entries, cid) do
    spec = {UploadClient, cid: cid}
    {:ok, pid} = Supervisor.start_child(fetch_test_supervisor!(), spec)
    Upload.new(pid, view, form_selector, name, entries, cid)
  end

  @doc """
  Returns the most recent title that was updated via a `page_title` assign.

  ## Examples

      render_click(view, :event_that_triggers_page_title_update)
      assert page_title(view) =~ "my title"

  """
  def page_title(view) do
    call(view, :page_title)
  end

  @doc """
  Asserts a live patch will happen within `timeout` milliseconds.
  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `assert_receive_timeout` (100 ms).

  It returns the new path.

  To assert on the flash message, you can assert on the result of the
  rendered LiveView.

  ## Examples

      render_click(view, :event_that_triggers_patch)
      assert_patch view

      render_click(view, :event_that_triggers_patch)
      assert_patch view, 30

      render_click(view, :event_that_triggers_patch)
      path = assert_patch view
      assert path =~ ~r/path/\d+/
  """
  def assert_patch(view, timeout \\ Application.fetch_env!(:ex_unit, :assert_receive_timeout))

  def assert_patch(view, timeout) when is_integer(timeout) do
    {path, _flash} = assert_navigation(view, :patch, nil, timeout)
    path
  end

  def assert_patch(view, to) when is_binary(to) do
    assert_patch(view, to, Application.fetch_env!(:ex_unit, :assert_receive_timeout))
  end

  @doc """
  Asserts a live patch will happen to a given path within `timeout`
  milliseconds.

  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `assert_receive_timeout` (100 ms).

  It returns the new path.

  To assert on the flash message, you can assert on the result of the
  rendered LiveView.

  ## Examples
      render_click(view, :event_that_triggers_patch)
      assert_patch view, "/path"

      render_click(view, :event_that_triggers_patch)
      assert_patch view, "/path", 30

  """
  def assert_patch(view, to, timeout)
      when is_binary(to) and is_integer(timeout) do
    {path, _flash} = assert_navigation(view, :patch, to, timeout)
    path
  end

  @doc """
  Asserts a live patch was performed, and returns the new path.

  To assert on the flash message, you can assert on the result of
  the rendered LiveView.

  ## Examples

      render_click(view, :event_that_triggers_redirect)
      assert_patched view, "/path"

  """
  def assert_patched(view, to) do
    assert_patch(view, to, 0)
  end

  @doc ~S"""
  Asserts a redirect will happen within `timeout` milliseconds.
  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `assert_receive_timeout` (100 ms).

  It returns a tuple containing the new path and the flash messages from said
  redirect, if any. Note the flash will contain string keys.

  ## Examples

      render_click(view, :event_that_triggers_redirect)
      {path, flash} = assert_redirect view
      assert flash["info"] == "Welcome"
      assert path =~ ~r/path\/\d+/

      render_click(view, :event_that_triggers_redirect)
      assert_redirect view, 30
  """
  def assert_redirect(view, timeout \\ Application.fetch_env!(:ex_unit, :assert_receive_timeout))

  def assert_redirect(view, timeout) when is_integer(timeout) do
    assert_navigation(view, :redirect, nil, timeout)
  end

  def assert_redirect(view, to) when is_binary(to) do
    assert_redirect(view, to, Application.fetch_env!(:ex_unit, :assert_receive_timeout))
  end

  @doc """
  Asserts a redirect will happen to a given path within `timeout` milliseconds.

  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `assert_receive_timeout` (100 ms).

  It returns the flash messages from said redirect, if any.
  Note the flash will contain string keys.

  ## Examples

      render_click(view, :event_that_triggers_redirect)
      flash = assert_redirect view, "/path"
      assert flash["info"] == "Welcome"

      render_click(view, :event_that_triggers_redirect)
      assert_redirect view, "/path", 30
  """
  def assert_redirect(view, to, timeout)
      when is_binary(to) and is_integer(timeout) do
    {_path, flash} = assert_navigation(view, :redirect, to, timeout)
    flash
  end

  @doc """
  Asserts a redirect was performed.

  It returns the flash messages from said redirect, if any. Note the
  flash will contain string keys.

  ## Examples

      render_click(view, :event_that_triggers_redirect)
      flash = assert_redirected view, "/path"
      assert flash["info"] == "Welcome"

  """
  def assert_redirected(view, to) do
    assert_redirect(view, to, 0)
  end

  defp assert_navigation(view, kind, to, timeout) do
    %{proxy: {ref, topic, _}, endpoint: endpoint} = view

    receive do
      {^ref, {^kind, ^topic, %{to: new_to} = opts}} when new_to == to or to == nil ->
        {new_to, Phoenix.LiveView.Utils.verify_flash(endpoint, opts[:flash])}
    after
      timeout ->
        message =
          if to do
            "expected #{inspect(view.module)} to #{kind} to #{inspect(to)}, "
          else
            "expected #{inspect(view.module)} to #{kind}, "
          end

        case flush_navigation(ref, topic, nil) do
          {new_kind, new_to} when new_to != to ->
            raise ArgumentError, message <> "but got a #{new_kind} to #{inspect(new_to)}"

          _ ->
            raise ArgumentError, message <> "but got none"
        end
    end
  end

  @doc """
  Refutes a redirect to a given path was performed.

  It returns :ok if the specified redirect isn't already in the mailbox.

  ## Examples

      render_click(view, :event_that_triggers_redirect_to_path)
      :ok = refute_redirected view, "/wrong_path"
  """
  def refute_redirected(view, to) when is_binary(to) do
    refute_navigation(view, :redirect, to)
  end

  defp refute_navigation(view = %{proxy: {ref, topic, _}}, kind, to) do
    receive do
      {^ref, {^kind, ^topic, %{to: new_to}}} when new_to == to or to == nil ->
        message =
          if to do
            "expected #{inspect(view.module)} not to #{kind} to #{inspect(to)}, "
          else
            "expected #{inspect(view.module)} not to #{kind}, "
          end

        raise ArgumentError, message <> "but got a #{kind} to #{inspect(to)}"
    after
      0 -> :ok
    end
  end

  defp flush_navigation(ref, topic, last) do
    receive do
      {^ref, {kind, ^topic, %{to: to}}} when kind in [:patch, :redirect] ->
        flush_navigation(ref, topic, {kind, to})
    after
      0 -> last
    end
  end

  @doc """
  Asserts an event will be pushed within `timeout`.
  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `assert_receive_timeout` (100 ms).

  ## Examples

      assert_push_event view, "scores", %{points: 100, user: "josé"}
  """
  defmacro assert_push_event(
             view,
             event,
             payload,
             timeout \\ Application.fetch_env!(:ex_unit, :assert_receive_timeout)
           ) do
    quote do
      %{proxy: {ref, _topic, _}} = unquote(view)

      assert_receive {^ref, {:push_event, unquote(event), unquote(payload)}}, unquote(timeout)
    end
  end

  @doc """
  Refutes an event will be pushed within timeout.

  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `refute_receive_timeout` (100 ms).

  ## Examples

      refute_push_event view, "scores", %{points: _, user: "josé"}
  """
  defmacro refute_push_event(
             view,
             event,
             payload,
             timeout \\ Application.fetch_env!(:ex_unit, :refute_receive_timeout)
           ) do
    quote do
      %{proxy: {ref, _topic, _}} = unquote(view)

      receive do
        {^ref, {:push_event, unquote(event), unquote(payload) = data}} ->
          flunk("""
          Unexpectedly received event "#{unquote(event)}"

          Payload:

          #{inspect(data, pretty: true)}
          """)
      after
        unquote(timeout) ->
          false
      end
    end
  end

  @doc """
  Asserts a hook reply was returned from a `handle_event` callback.

  The default `timeout` is [ExUnit](https://hexdocs.pm/ex_unit/ExUnit.html#configure/1)'s
  `assert_receive_timeout` (100 ms).

  ## Examples

      assert_reply view, %{result: "ok", transaction_id: _}
  """
  defmacro assert_reply(
             view,
             payload,
             timeout \\ Application.fetch_env!(:ex_unit, :assert_receive_timeout)
           ) do
    quote do
      %{proxy: {ref, _topic, _}} = unquote(view)

      assert_receive {^ref, {:reply, unquote(payload)}}, unquote(timeout)
    end
  end

  @doc """
  Follows the redirect from a `render_*` action or an `{:error, redirect}`
  tuple.

  Imagine you have a LiveView that redirects on a `render_click`
  event. You can make sure it immediately redirects after the
  `render_click` action by calling `follow_redirect/3`:

      live_view
      |> render_click("redirect")
      |> follow_redirect(conn)

  Or in the case of an error tuple:

      assert {:error, {:redirect, %{to: "/somewhere"}}} = result = live(conn, "my-path")
      {:ok, view, body} = follow_redirect(result, conn, :gameboy)

  `follow_redirect/3` expects a connection as second argument.
  This is the connection that will be used to perform the underlying
  request.

  If the LiveView redirects with a live redirect, this macro returns
  `{:ok, live_view, disconnected_body}` with the content of the new
  LiveView, the same as the `live/3` macro. If the LiveView redirects
  with a regular redirect, this macro returns `{:ok, conn}` with the
  rendered redirected page. In any other case, this macro raises.

  Finally, note that you can optionally assert on the path you are
  being redirected to by passing a third argument:

      live_view
      |> render_click("redirect")
      |> follow_redirect(conn, "/redirected/page")

  """
  defmacro follow_redirect(reason, conn, to \\ nil) do
    quote bind_quoted: binding() do
      case reason do
        {:error, {:live_redirect, opts}} ->
          {conn, to} = Phoenix.LiveViewTest.__follow_redirect__(conn, @endpoint, to, opts)
          live(conn, to)

        {:error, {:redirect, opts}} ->
          {conn, to} = Phoenix.LiveViewTest.__follow_redirect__(conn, @endpoint, to, opts)
          {:ok, get(conn, to)}

        _ ->
          raise "LiveView did not redirect"
      end
    end
  end

  @doc false
  def __follow_redirect__(conn, endpoint, expected_to, %{to: to} = opts) do
    if expected_to && expected_to != to do
      raise ArgumentError,
            "expected LiveView to redirect to #{inspect(expected_to)}, but got #{inspect(to)}"
    end

    conn = Phoenix.ConnTest.ensure_recycled(conn)

    if flash = opts[:flash] do
      {Phoenix.ConnTest.put_req_cookie(conn, @flash_cookie, ensure_signed_flash(endpoint, flash)),
       to}
    else
      {conn, to}
    end
  end

  defp ensure_signed_flash(endpoint, flash) when is_map(flash) do
    Phoenix.LiveView.Utils.sign_flash(endpoint, flash)
  end

  defp ensure_signed_flash(_, flash), do: flash

  @doc """
  Performs a live redirect from one LiveView to another.

  When redirecting between two LiveViews of the same `live_session`,
  mounts the new LiveView and shutsdown the previous one, which
  mimics general browser live navigation behaviour.

  When attempting to navigate from a LiveView of a different
  `live_session`, an error redirect condition is returned indicating
  a failed `push_navigate` from the client.

  ## Examples

      assert {:ok, page_live, _body} = live(conn, "/page/1", _format: :gameboy)
      assert {:ok, page2_live, _body} = live(conn, "/page/2", _format: :gameboy)

      assert {:error, {:redirect, _}} = live_redirect(page2_live, to: "/admin")
  """
  def live_redirect(view, opts) do
    __live_redirect__(view, opts)
  end

  @doc false
  def __live_redirect__(%View{} = view, opts, token_func \\ & &1) do
    {session, %ClientProxy{} = root} = ClientProxy.root_view(proxy_pid(view))

    url =
      case Keyword.fetch!(opts, :to) do
        "/" <> _ = path -> URI.merge(root.uri, path)
        url -> url
      end

    live_module =
      case Phoenix.LiveView.Route.live_link_info_without_checks(root.endpoint, root.router, url) do
        {:internal, route} ->
          route.view

        _ ->
          raise ArgumentError, """
          attempted to navigate to a non-live route at #{inspect(url)}
          """
      end

    body = render(view)
    ClientProxy.stop(proxy_pid(view), {:shutdown, :duplicate_topic})
    root_token = token_func.(root.session_token)
    static_token = token_func.(root.static_token)

    start_proxy(url, %{
      response: body,
      live_redirect: {root.id, root_token, static_token},
      connect_params: root.connect_params,
      connect_info: root.connect_info,
      live_module: live_module,
      endpoint: root.endpoint,
      router: root.router,
      session: session,
      url: url
    })
  end

  @doc """
  Receives a `form_element` and asserts that `phx-trigger-action` has been
  set to true, following up on that request.

  Imagine you have a LiveView that sends an HTTP form submission. Say that it
  sets the `phx-trigger-action` to true, as a response to a submit event.
  You can follow the trigger action like this:

      form = form(live_view, selector, %{"form" => "data"})

      # First we submit the form. Optionally verify that phx-trigger-action
      # is now part of the form.
      assert render_submit(form) =~ ~r/phx-trigger-action/

      # Now follow the request made by the form
      conn = follow_trigger_action(form, conn)
      assert conn.method == "POST"
      assert conn.params == %{"form" => "data"}

  """
  defmacro follow_trigger_action(form, conn) do
    quote bind_quoted: binding() do
      {method, path, form_data} =
        Phoenix.LiveViewTest.__render_trigger_submit__(
          form,
          :follow_trigger_action,
          "phx-trigger-action",
          "could not follow trigger action because form #{inspect(form.selector)} " <>
            "does not have a phx-trigger-action attribute"
        )

      dispatch(conn, @endpoint, method, path, form_data)
    end
  end

  @doc """
  Receives a form element and submits the HTTP request through the plug pipeline.

  Imagine you have a LiveView that validates form data, but submits the form to
  a controller via the normal form `action` attribute. This is especially useful
  in scenarios where the result of a form submit needs to write to the plug session.

  You can follow submit the form with the `%Plug.Conn{}`, like this:

      form = form(live_view, selector, %{"form" => "data"})

      # Now submit the LiveView form to the plug pipeline
      conn = submit_form(form, conn)
      assert conn.method == "POST"
      assert conn.params == %{"form" => "data"}
  """
  defmacro submit_form(form, conn) do
    quote bind_quoted: binding() do
      {method, path, form_data} =
        Phoenix.LiveViewTest.__render_trigger_submit__(
          form,
          :submit_form,
          "action",
          "could not submit form because form #{inspect(form.selector)} " <>
            "does not have an action attribute"
        )

      dispatch(conn, @endpoint, method, path, form_data)
    end
  end

  def __render_trigger_submit__(%Element{} = form, name, required_attr, error_msg) do
    case render_tree(form) do
      {"form", attrs, _child_nodes} ->
        if not List.keymember?(attrs, required_attr, 0) do
          raise ArgumentError, error_msg <> ", got: #{inspect(attrs)}"
        end

        {"action", path} = List.keyfind(attrs, "action", 0) || {"action", call(form, :url)}
        {"method", method} = List.keyfind(attrs, "method", 0) || {"method", "get"}
        {method, path, form.form_data || %{}}

      {tag, _, _} ->
        raise ArgumentError,
              "could not #{name} because given element did not return a form, " <>
                "got #{inspect(tag)} instead"
    end
  end

  defp proxy_pid(%{proxy: {_ref, _topic, pid}}), do: pid

  defp proxy_topic(%{proxy: {_ref, topic, _pid}}), do: topic

  @doc"""
  Asserts the given status code, that we have a LiveCiewNative client response and
  returns the response body if one was set or sent.

  The 3rd argument should correspond with the client's format name.

  ## Examples

      assert lvn_response(conn, 200, :gameboy) =~ "<GameBoyLayout>"
  """
  def lvn_response(conn, status, format) do
    body = Phoenix.ConnTest.response(conn, status)
    _    = Phoenix.ConnTest.response_content_type(conn, format)
    body
  end

  @doc """
  Performs an upload of a file input and renders the result.

  See `file_input/4` for details on building a file input.

  ## Examples

  Given the following LiveView template:

  ```heex
  <%= for entry <- @uploads.avatar.entries do %>
    <%= entry.name %>: <%= entry.progress %>%
  <% end %>
  ```

  Your test case can assert the uploaded content:

      avatar = file_input(lv, "#my-form-id", :avatar, [
        %{
          last_modified: 1_594_171_879_000,
          name: "myfile.jpeg",
          content: File.read!("myfile.jpg"),
          size: 1_396_009,
          type: "image/jpeg"
        }
      ])

      assert render_upload(avatar, "myfile.jpeg") =~ "100%"

  By default, the entire file is chunked to the server, but an optional
  percentage to chunk can be passed to test chunk-by-chunk uploads:

      assert render_upload(avatar, "myfile.jpeg", 49) =~ "49%"
      assert render_upload(avatar, "myfile.jpeg", 51) =~ "100%"

  Before making assertions about the how the upload is consumed server-side,
  you will need to call `render_submit/1`.

  In the case where an upload progress callback issues a navigate, patch, or
  redirect, the following will be returned:

    * for a patch, the current view will be patched
    * for a navigate, this function will return
      `{:error, {:live_redirect, %{to: url}}}`, which can be followed
      with `follow_redirect/2`
    * for a regular redirect, this function will return
      `{:error, {:redirect, %{to: url}}}`, which can be followed
      with `follow_redirect/2`
  """
  def render_upload(%Upload{} = upload, entry_name, percent \\ 100) do
    entry_ref =
      Enum.find_value(upload.entries, fn
        %{"name" => ^entry_name, "ref" => ref} -> ref
        %{} -> nil
      end)

    if !entry_name do
      raise ArgumentError, "no such entry with name #{inspect(entry_name)}"
    end

    case UploadClient.fetch_allow_acknowledged(upload, entry_name) do
      {:ok, _token} ->
        render_chunk(upload, entry_name, percent)

      {:error, :nopreflight} ->
        case preflight_upload(upload) do
          {:ok, %{ref: ref, config: config, entries: entries_resp, errors: errors}} ->
            if entry_errors = errors[entry_ref] do
              UploadClient.allowed_ack(upload, ref, config, entry_name, entries_resp, errors)
              {:error, for(reason <- entry_errors, do: [entry_ref, reason])}
            else
              case UploadClient.allowed_ack(upload, ref, config, entry_name, entries_resp, errors) do
                :ok -> render_chunk(upload, entry_name, percent)
                {:error, reason} -> {:error, reason}
              end
            end

          {:error, reason} ->
            {:error, reason}
        end

      {:error, reason} ->
        {:error, reason}
    end
  end

  @doc """
  Performs a preflight upload request.

  Useful for testing external uploaders to retrieve the `:external` entry metadata.

  ## Examples

      avatar = file_input(lv, "#my-form-id", :avatar, [%{name: ..., ...}, ...])
      assert {:ok, %{ref: _ref, config: %{chunk_size: _}}} = preflight_upload(avatar)
  """
  def preflight_upload(%Upload{} = upload) do
    # LiveView channel returns error conditions as error key in payload, ie `%{error: reason}`
    case call(
           upload.element,
           {:render_event, upload.element, :allow_upload, {upload.entries, upload.cid}}
         ) do
      %{error: reason} -> {:error, reason}
      %{ref: _ref} = resp -> {:ok, resp}
    end
  end

  defp render_chunk(upload, entry_name, percent) do
    %{proxy: {_ref, _topic, pid}} = upload.view
    monitor_ref = Process.monitor(pid)

    try do
      case UploadClient.chunk(upload, entry_name, percent, proxy_pid(upload.view)) do
        {:ok, _} ->
          render(upload.view)

        {:error, reason} ->
          {:error, reason}
      end
    catch
      :exit, reason ->
        receive do
          {:DOWN, ^monitor_ref, :process, _pid, {:shutdown, {:live_redirect, opts}}} ->
            {:error, {:live_redirect, opts}}

          {:DOWN, ^monitor_ref, :process, _pid, {:shutdown, {:redirect, opts}}} ->
            {:error, {:redirect, opts}}
        after
          0 -> exit(reason)
        end
    end
  end
end