Task: Improve tests for ModuleDiscoveryService (#317)

* add test for all_modules/0

* better mocking

* improve module discovery service tests

Author: GuzekAlan

lib/live_debugger/services/module_discovery_service.ex

@@ -21,9 +21,9 @@ defmodule LiveDebugger.Services.ModuleDiscoveryService do
   Returns a list of loaded LiveView modules.
   """
 
-  @spec live_view_modules(loaded_modules :: [module()]) :: [module()]
-  def live_view_modules(loaded_modules) do
-    find_modules_by_behaviour(loaded_modules, @live_view_behaviour)
+  @spec live_view_modules(modules :: [module()]) :: [module()]
+  def live_view_modules(modules) do
+    find_modules_by_behaviour(modules, @live_view_behaviour)
   end
 
   @doc """
@@ -37,13 +37,13 @@ defmodule LiveDebugger.Services.ModuleDiscoveryService do
   iex> LiveDebugger.Services.ModuleDiscoveryService.live_view_modules(services)
   [MyAppWeb.LiveComponent, ...]
   """
-  @spec live_component_modules(loaded_modules :: [module()]) :: [module()]
-  def live_component_modules(loaded_modules) do
-    find_modules_by_behaviour(loaded_modules, @live_component_behaviour)
+  @spec live_component_modules(modules :: [module()]) :: [module()]
+  def live_component_modules(modules) do
+    find_modules_by_behaviour(modules, @live_component_behaviour)
   end
 
-  defp find_modules_by_behaviour(loaded_modules, behaviour) do
-    loaded_modules
+  defp find_modules_by_behaviour(modules, behaviour) do
+    modules
     |> Enum.filter(&ModuleService.loaded?/1)
     |> Enum.reject(&debugger?/1)
     |> Enum.filter(&behaviour?(&1, behaviour))

test/services/module_discovery_service_test.exs

@@ -4,78 +4,105 @@ defmodule LiveDebugger.Services.ModuleDiscoveryServiceTest do
   import Mox
 
   alias LiveDebugger.Services.ModuleDiscoveryService
+  alias LiveDebugger.MockModuleService
+
+  @modules [
+    CoolApp.LiveViews.UserDashboard,
+    CoolApp.LiveViews.UserProfile,
+    CoolApp.Service.UserService,
+    CoolApp.LiveComponent.UserElement,
+    CoolApp.LiveComponent.UserSettings
+  ]
+
+  test "all_modules/0 returns all modules" do
+    modules = @modules
+
+    MockModuleService
+    |> expect(:all, fn ->
+      Enum.map(modules, fn module ->
+        {to_charlist(module), to_charlist("/prefix/lib/#{module}.beam"),
+         module == CoolApp.LiveViews.UserDashboard}
+      end)
+    end)
+
+    assert modules == ModuleDiscoveryService.all_modules()
+  end
 
   describe "live_view_modules/1" do
     test "filters LiveView modules correctly" do
-      modules = [
-        CoolApp.LiveViews.UserDashboard,
-        CoolApp.Service.UserService,
-        CoolApp.LiveComponent.UserElement
-      ]
-
-      LiveDebugger.MockModuleService
-      |> expect(:loaded?, 3, fn _module -> true end)
-      |> expect(:behaviours, 3, fn module ->
-        case module do
-          CoolApp.LiveViews.UserDashboard -> [Phoenix.LiveView]
-          CoolApp.Service.UserService -> []
-          CoolApp.LiveComponent.UserElement -> [Phoenix.LiveComponent]
-        end
+      modules = @modules
+
+      MockModuleService
+      |> expect(:loaded?, 5, fn _module -> true end)
+      |> expect(:behaviours, 5, fn module ->
+        get_behaviours(module)
       end)
 
-      result = ModuleDiscoveryService.live_view_modules(modules)
-      assert result == [CoolApp.LiveViews.UserDashboard]
+      assert ModuleDiscoveryService.live_view_modules(modules) == [
+               CoolApp.LiveViews.UserDashboard,
+               CoolApp.LiveViews.UserProfile
+             ]
     end
 
     test "filters unloaded modules correctly" do
-      modules = [
-        CoolApp.LiveViews.UserDashboard,
-        CoolApp.Service.UserService,
-        CoolApp.LiveComponent.UserElement
-      ]
+      modules = @modules
 
-      LiveDebugger.MockModuleService
-      |> expect(:loaded?, 3, fn _module -> false end)
+      MockModuleService
+      |> expect(:loaded?, 5, fn
+        CoolApp.LiveViews.UserDashboard -> false
+        _ -> true
+      end)
+      |> expect(:behaviours, 4, fn module ->
+        get_behaviours(module)
+      end)
 
-      result = ModuleDiscoveryService.live_view_modules(modules)
-      assert result == []
+      assert ModuleDiscoveryService.live_view_modules(modules) == [
+               CoolApp.LiveViews.UserProfile
+             ]
     end
   end
 
   describe "live_component_modules/1" do
     test "filters LiveComponent modules correctly" do
-      loaded_modules = [
-        CoolApp.LiveViews.UserDashboard,
-        CoolApp.Service.UserService,
-        CoolApp.LiveComponent.UserElement
-      ]
-
-      LiveDebugger.MockModuleService
-      |> expect(:loaded?, 3, fn _module -> true end)
-      |> expect(:behaviours, 3, fn module ->
-        case module do
-          CoolApp.LiveViews.UserDashboard -> [Phoenix.LiveView]
-          CoolApp.Service.UserService -> []
-          CoolApp.LiveComponent.UserElement -> [Phoenix.LiveComponent]
-        end
+      modules = @modules
+
+      MockModuleService
+      |> expect(:loaded?, 5, fn _module -> true end)
+      |> expect(:behaviours, 5, fn module ->
+        get_behaviours(module)
       end)
 
-      result = ModuleDiscoveryService.live_component_modules(loaded_modules)
-      assert result == [CoolApp.LiveComponent.UserElement]
+      assert ModuleDiscoveryService.live_component_modules(modules) == [
+               CoolApp.LiveComponent.UserElement,
+               CoolApp.LiveComponent.UserSettings
+             ]
     end
 
     test "filters unloaded modules correctly" do
-      modules = [
-        CoolApp.LiveViews.UserDashboard,
-        CoolApp.Service.UserService,
-        CoolApp.LiveComponent.UserElement
-      ]
+      modules = @modules
 
-      LiveDebugger.MockModuleService
-      |> expect(:loaded?, 3, fn _module -> false end)
+      MockModuleService
+      |> expect(:loaded?, 5, fn
+        CoolApp.LiveComponent.UserElement -> false
+        _ -> true
+      end)
+      |> expect(:behaviours, 4, fn module ->
+        get_behaviours(module)
+      end)
+
+      assert ModuleDiscoveryService.live_component_modules(modules) == [
+               CoolApp.LiveComponent.UserSettings
+             ]
+    end
+  end
 
-      result = ModuleDiscoveryService.live_component_modules(modules)
-      assert result == []
+  defp get_behaviours(module) do
+    case module do
+      CoolApp.LiveViews.UserDashboard -> [Phoenix.LiveView]
+      CoolApp.LiveViews.UserProfile -> [Phoenix.LiveView]
+      CoolApp.Service.UserService -> []
+      CoolApp.LiveComponent.UserElement -> [Phoenix.LiveComponent]
+      CoolApp.LiveComponent.UserSettings -> [Phoenix.LiveComponent]
     end
   end
 end