Task: Add more tests for LiveViewDiscoveryService (#310)

* add debugged_lv_process test

* add tests for lv_process/2

* refactor and test successor_lv_process/1

* add test for group_lv_processes/1

* add test for lv_processes/0

Author: GuzekAlan

lib/live_debugger/live_views/channel_dashboard_live.ex

@@ -5,6 +5,7 @@ defmodule LiveDebugger.LiveViews.ChannelDashboardLive do
 
   require Logger
 
+  alias LiveDebugger.Structs.LvProcess
   alias Phoenix.LiveView.JS
   alias LiveDebugger.Utils.URL
   alias Phoenix.LiveView.AsyncResult
@@ -98,11 +99,10 @@ defmodule LiveDebugger.LiveViews.ChannelDashboardLive do
   @impl true
   def handle_async(:fetch_lv_process, {:ok, nil}, socket) do
     with %{debugged_module: module} when not is_nil(module) <- socket.assigns,
-         [lv_process] <- LiveViewDiscoveryService.successor_lv_processes(module) do
+         %LvProcess{socket_id: socket_id, transport_pid: transport_pid} <-
+           LiveViewDiscoveryService.successor_lv_process(module) do
       socket
-      |> push_navigate(
-        to: Routes.channel_dashboard(lv_process.socket_id, lv_process.transport_pid)
-      )
+      |> push_navigate(to: Routes.channel_dashboard(socket_id, transport_pid))
       |> noreply()
     else
       _ ->

lib/live_debugger/services/live_view_discovery_service.ex

@@ -46,15 +46,20 @@ defmodule LiveDebugger.Services.LiveViewDiscoveryService do
   end
 
   @doc """
-  Finds potential successor LvProcess based on module when websocket connection breaks and new one is created.
-  This is a common scenario when user recompiles code or refreshes the page
+  Finds potential successors LvProcesses based on module when websocket connection breaks and new one is created.
+  This is a common scenario when user recompiles code or refreshes the page.
+  When more than one process is found, `nil` is returned.
   """
-  @spec successor_lv_processes(module :: module()) :: [LvProcess.t()]
-  def successor_lv_processes(module) do
+  @spec successor_lv_process(module :: module()) :: LvProcess.t() | nil
+  def successor_lv_process(module) when is_atom(module) do
     lv_processes()
     |> Enum.filter(fn lv_process ->
-      not lv_process.debugger? and lv_process.module == module
+      lv_process.module == module
     end)
+    |> case do
+      [lv_process] -> lv_process
+      _ -> nil
+    end
   end
 
   @doc """

test/services/live_view_discovery_service_test.exs

@@ -55,6 +55,29 @@ defmodule LiveDebugger.Services.LiveViewDiscoveryServiceTest do
     end
   end
 
+  test "debugger_lv_processes/0 returns only LiveDebugger LvProcesses" do
+    live_debugger_pid = :c.pid(0, 0, 2)
+    live_view_pid = :c.pid(0, 0, 1)
+
+    live_debugger_module = :"Elixir.LiveDebugger.SomLiveView"
+    live_view_module = :"Elixir.SomeLiveView"
+
+    MockProcessService
+    |> expect(:list, fn -> [live_debugger_pid, live_view_pid] end)
+    |> expect(:initial_call, fn _ -> {live_debugger_module, :mount} end)
+    |> expect(:initial_call, fn _ -> {live_view_module, :mount} end)
+    |> expect(:state, fn ^live_debugger_pid ->
+      {:ok, Fakes.state(root_pid: live_debugger_pid, module: live_debugger_module)}
+    end)
+    |> expect(:state, fn ^live_view_pid ->
+      {:ok, Fakes.state(root_pid: live_view_pid, module: live_view_module)}
+    end)
+
+    assert [
+             %LvProcess{pid: ^live_debugger_pid}
+           ] = LiveViewDiscoveryService.debugger_lv_processes()
+  end
+
   describe "lv_process/1" do
     test "returns LvProcess based on socket_id" do
       searched_live_view_pid = :c.pid(0, 1, 0)
@@ -112,6 +135,230 @@ defmodule LiveDebugger.Services.LiveViewDiscoveryServiceTest do
     end
   end
 
+  describe "lv_process/2" do
+    test "returns LvProcess based on socket_id and transport_pid" do
+      searched_live_view_pid = :c.pid(0, 1, 0)
+      searched_module = :"Elixir.SearchedLiveView"
+      socket_id = "phx-GBsi_6M7paYhySQj"
+      transport_pid = :c.pid(0, 7, 1)
+
+      live_view_pid_1 = :c.pid(0, 0, 1)
+      live_view_pid_2 = :c.pid(0, 0, 2)
+      other_module = :"Elixir.SomeLiveView"
+      other_socket_id = "phx-other-socket"
+      other_transport_pid = :c.pid(0, 7, 2)
+
+      MockProcessService
+      |> expect(:list, fn -> [searched_live_view_pid, live_view_pid_1, live_view_pid_2] end)
+      |> expect(:initial_call, fn _ -> {searched_module, :mount} end)
+      |> expect(:initial_call, 2, fn _ -> {other_module, :mount} end)
+      |> expect(:state, fn ^searched_live_view_pid ->
+        {:ok,
+         Fakes.state(
+           root_pid: searched_live_view_pid,
+           module: searched_module,
+           socket_id: socket_id,
+           transport_pid: transport_pid
+         )}
+      end)
+      |> expect(:state, fn live_view_pid ->
+        {:ok,
+         Fakes.state(
+           root_pid: live_view_pid,
+           module: other_module,
+           socket_id: other_socket_id,
+           transport_pid: transport_pid
+         )}
+      end)
+      |> expect(:state, fn live_view_pid ->
+        {:ok,
+         Fakes.state(
+           root_pid: live_view_pid,
+           module: other_module,
+           socket_id: socket_id,
+           transport_pid: other_transport_pid
+         )}
+      end)
+
+      assert %LvProcess{pid: ^searched_live_view_pid} =
+               LiveViewDiscoveryService.lv_process(socket_id, transport_pid)
+    end
+
+    test "returns nil if no LiveView process of given socket_id and transport_pid" do
+      socket_id = "phx-GBsi_6M7paYhySQj"
+      transport_pid = :c.pid(0, 7, 1)
+
+      live_view_pid_1 = :c.pid(0, 0, 1)
+      live_view_pid_2 = :c.pid(0, 0, 2)
+
+      other_socket_id = "phx-other-socket"
+      other_transport_pid = :c.pid(0, 7, 2)
+
+      MockProcessService
+      |> expect(:list, fn -> [live_view_pid_1, live_view_pid_2] end)
+      |> expect(:initial_call, 2, fn _ -> {:"Elixir.SomeLiveView", :mount} end)
+      |> expect(:state, fn live_view_pid ->
+        {:ok,
+         Fakes.state(
+           root_pid: live_view_pid,
+           socket_id: other_socket_id,
+           transport_pid: transport_pid
+         )}
+      end)
+      |> expect(:state, fn live_view_pid ->
+        {:ok,
+         Fakes.state(
+           root_pid: live_view_pid,
+           socket_id: socket_id,
+           transport_pid: other_transport_pid
+         )}
+      end)
+
+      assert nil ==
+               LiveViewDiscoveryService.lv_process(socket_id, transport_pid)
+    end
+  end
+
+  describe "successor_lv_process/1" do
+    test "returns successor LvProcesses of the given module" do
+      successor_pid = :c.pid(0, 0, 1)
+      live_view_pid = :c.pid(0, 1, 0)
+
+      successor_module = :"Elixir.SomeLiveView"
+      other_module = :"Elixir.OtherLiveView"
+
+      MockProcessService
+      |> expect(:list, fn -> [successor_pid, live_view_pid] end)
+      |> expect(:initial_call, fn _ -> {successor_module, :mount} end)
+      |> expect(:initial_call, fn _ -> {other_module, :mount} end)
+      |> expect(:state, fn ^successor_pid ->
+        {:ok, Fakes.state(root_pid: successor_pid, module: successor_module)}
+      end)
+      |> expect(:state, fn ^live_view_pid ->
+        {:ok, Fakes.state(root_pid: live_view_pid, module: other_module)}
+      end)
+
+      assert %LvProcess{pid: ^successor_pid} =
+               LiveViewDiscoveryService.successor_lv_process(successor_module)
+    end
+
+    test "returns nil if no LiveView process of given module" do
+      live_view_pid = :c.pid(0, 0, 1)
+
+      successor_module = :"Elixir.SomeLiveView"
+      other_module = :"Elixir.OtherLiveView"
+
+      MockProcessService
+      |> expect(:list, fn -> [live_view_pid] end)
+      |> expect(:initial_call, fn _ -> {other_module, :mount} end)
+      |> expect(:state, fn ^live_view_pid ->
+        {:ok, Fakes.state(root_pid: live_view_pid, module: other_module)}
+      end)
+
+      assert nil == LiveViewDiscoveryService.successor_lv_process(successor_module)
+    end
+
+    test "returns nil if more than one LiveViewProcess of given module found" do
+      live_view_pid_1 = :c.pid(0, 0, 1)
+      live_view_pid_2 = :c.pid(0, 0, 2)
+
+      successor_module = :"Elixir.SomeLiveView"
+
+      MockProcessService
+      |> expect(:list, fn -> [live_view_pid_1, live_view_pid_2] end)
+      |> expect(:initial_call, 2, fn _ -> {successor_module, :mount} end)
+      |> expect(:state, 2, fn live_view_pid ->
+        {:ok, Fakes.state(root_pid: live_view_pid, module: successor_module)}
+      end)
+
+      assert nil == LiveViewDiscoveryService.successor_lv_process(successor_module)
+    end
+  end
+
+  test "group_lv_processes/1 groups LvProcesses into proper map" do
+    pid_1 = :c.pid(0, 0, 1)
+    pid_2 = :c.pid(0, 0, 2)
+
+    root_pid_1 = :c.pid(0, 1, 1)
+    root_pid_2 = :c.pid(0, 1, 2)
+    root_pid_3 = :c.pid(0, 1, 3)
+
+    transport_pid_1 = :c.pid(0, 7, 1)
+    transport_pid_2 = :c.pid(0, 7, 2)
+
+    lv_process_1 = %LvProcess{
+      pid: root_pid_1,
+      root_pid: root_pid_1,
+      transport_pid: transport_pid_1
+    }
+
+    lv_process_2 = %LvProcess{
+      pid: pid_1,
+      root_pid: root_pid_1,
+      transport_pid: transport_pid_1
+    }
+
+    lv_process_3 = %LvProcess{
+      pid: root_pid_2,
+      root_pid: root_pid_2,
+      transport_pid: transport_pid_2
+    }
+
+    lv_process_4 = %LvProcess{
+      pid: pid_2,
+      root_pid: root_pid_2,
+      transport_pid: transport_pid_2
+    }
+
+    lv_process_5 = %LvProcess{
+      pid: root_pid_3,
+      root_pid: root_pid_3,
+      transport_pid: transport_pid_2
+    }
+
+    assert %{
+             transport_pid_1 => %{
+               lv_process_1 => [lv_process_2]
+             },
+             transport_pid_2 => %{
+               lv_process_3 => [lv_process_4],
+               lv_process_5 => []
+             }
+           } ==
+             LiveViewDiscoveryService.group_lv_processes([
+               lv_process_1,
+               lv_process_2,
+               lv_process_3,
+               lv_process_4,
+               lv_process_5
+             ])
+  end
+
+  test "lv_processes/0 returns all LiveView processes" do
+    live_view_pid_1 = :c.pid(0, 0, 1)
+    live_view_pid_2 = :c.pid(0, 0, 2)
+    non_live_view_pid = :c.pid(0, 0, 3)
+
+    module = :"Elixir.SomeLiveView"
+    non_live_view_module = :"Elixir.SomeOtherModule"
+
+    MockProcessService
+    |> expect(:list, fn -> [live_view_pid_1, live_view_pid_2, non_live_view_pid] end)
+    |> expect(:initial_call, 2, fn _ -> {module, :mount} end)
+    |> expect(:initial_call, fn _ -> {non_live_view_module, :some_initial_call} end)
+    |> expect(:state, fn ^live_view_pid_1 ->
+      {:ok, Fakes.state(root_pid: live_view_pid_1, module: module)}
+    end)
+    |> expect(:state, fn ^live_view_pid_2 ->
+      {:ok, Fakes.state(root_pid: live_view_pid_2, module: module)}
+    end)
+
+    assert [
+             %LvProcess{pid: ^live_view_pid_1},
+             %LvProcess{pid: ^live_view_pid_2}
+           ] = LiveViewDiscoveryService.lv_processes()
+  end
+
   describe "children_lv_processes/1" do
     test "returns children LvProcesses of the given pid" do
       parent_pid = :c.pid(0, 0, 1)

test/support/fakes.ex

@@ -7,6 +7,7 @@ defmodule LiveDebugger.Fakes do
     socket_id = Keyword.get(opts, :socket_id, "phx-GBsi_6M7paYhySQj")
     root_pid = Keyword.get(opts, :root_pid, :c.pid(0, 0, 0))
     parent_pid = Keyword.get(opts, :parent_pid, nil)
+    transport_pid = Keyword.get(opts, :transport_pid, :c.pid(0, 7, 0))
     module = Keyword.get(opts, :module, LiveDebugger.LiveViews.Main)
 
     %{
@@ -17,6 +18,7 @@ defmodule LiveDebugger.Fakes do
         parent_pid: parent_pid,
         root_pid: root_pid,
         router: LiveDebuggerDev.Router,
+        transport_pid: transport_pid,
         assigns: %{
           assign: :value,
           counter: 0,