Add conversation show endpoint

lib/code_corps/messages/messages.ex

@@ -29,6 +29,14 @@ defmodule CodeCorps.Messages do
     |> Repo.all()
   end
 
+  @doc ~S"""
+  Gets a `CodeCorps.Conversation` record
+  """
+  @spec get_conversation(integer) :: Conversation.t
+  def get_conversation(id) do
+    Conversation |> Repo.get(id)
+  end
+
   @doc ~S"""
   Creates a `CodeCorps.Message` from a set of parameters.
   """

lib/code_corps/policy/conversation.ex

@@ -4,9 +4,11 @@ defmodule CodeCorps.Policy.Conversation do
   records.
   """
 
+  import CodeCorps.Policy.Helpers,
+    only: [administered_by?: 2, get_message: 1, get_project: 1]
   import Ecto.Query
 
-  alias CodeCorps.{Message, Policy, Repo, User}
+  alias CodeCorps.{Conversation, Message, Policy, Repo, User}
 
   @spec scope(Ecto.Queryable.t, User.t) :: Ecto.Queryable.t
   def scope(queryable, %User{admin: true}), do: queryable
@@ -21,4 +23,13 @@ defmodule CodeCorps.Policy.Conversation do
     |> where(user_id: ^id)
     |> or_where([c], c.message_id in ^scoped_message_ids)
   end
+
+  def show?(%User{id: user_id}, %Conversation{user_id: target_user_id})
+    when user_id == target_user_id do
+    true
+  end
+  def show?(%User{} = user, %Conversation{} = conversation) do
+    conversation |> get_message() |> get_project() |> administered_by?(user)
+  end
+  def show?(_, _), do: false
 end

lib/code_corps/policy/helpers.ex

@@ -5,6 +5,8 @@ defmodule CodeCorps.Policy.Helpers do
   """
 
   alias CodeCorps.{
+    Conversation,
+    Message,
     Organization,
     ProjectUser,
     Project,
@@ -98,6 +100,14 @@ defmodule CodeCorps.Policy.Helpers do
   defp owner?("owner"), do: true
   defp owner?(_), do: false
 
+  @doc """
+  Retrieves message from associated record
+  """
+  @spec get_message(Changeset.t() | Conversation.t() | map) :: Message.t()
+  def get_message(%Conversation{message_id: message_id}), do: Repo.get(Message, message_id)
+  def get_message(%{"message_id" => message_id}), do: Repo.get(Message, message_id)
+  def get_message(%Changeset{changes: %{message_id: message_id}}), do: Repo.get(Message, message_id)
+
   @doc """
   Retrieves task from associated record
   """

lib/code_corps/policy/policy.ex

@@ -40,6 +40,9 @@ defmodule CodeCorps.Policy do
   defp can?(%User{} = current_user, :create, %Comment{}, %{} = params), do: Policy.Comment.create?(current_user, params)
   defp can?(%User{} = current_user, :update, %Comment{} = comment, %{}), do: Policy.Comment.update?(current_user, comment)
 
+  # Conversation
+  defp can?(%User{} = current_user, :show, %Conversation{} = conversation, %{}), do: Policy.Conversation.show?(current_user, conversation)
+
   # DonationGoal
   defp can?(%User{} = current_user, :create, %DonationGoal{}, %{} = params), do: Policy.DonationGoal.create?(current_user, params)
   defp can?(%User{} = current_user, :update, %DonationGoal{} = donation_goal, %{}), do: Policy.DonationGoal.update?(current_user, donation_goal)

lib/code_corps_web/controllers/conversation_controller.ex

@@ -19,4 +19,13 @@ defmodule CodeCorpsWeb.ConversationController do
       conn |> render("index.json-api", data: conversations)
     end
   end
+
+  @spec show(Conn.t, map) :: Conn.t
+  def show(%Conn{} = conn, %{"id" => id}) do
+    with %User{} = current_user <- conn |> CodeCorps.Guardian.Plug.current_resource,
+      %Conversation{} = conversation <- Messages.get_conversation(id),
+      {:ok, :authorized} <- current_user |> Policy.authorize(:show, conversation, %{}) do
+      conn |> render("show.json-api", data: conversation)
+    end
+  end
 end

lib/code_corps_web/router.ex

@@ -71,7 +71,7 @@ defmodule CodeCorpsWeb.Router do
 
     resources "/categories", CategoryController, only: [:create, :update]
     resources "/comments", CommentController, only: [:create, :update]
-    resources "/conversations", ConversationController, only: [:index]
+    resources "/conversations", ConversationController, only: [:index, :show]
     resources "/donation-goals", DonationGoalController, only: [:create, :update, :delete]
     post "/oauth/github", UserController, :github_oauth
     resources "/github-app-installations", GithubAppInstallationController, only: [:create]

test/lib/code_corps/helpers/policy_test.exs

@@ -54,7 +54,6 @@ defmodule CodeCorps.Policy.HelpersTest do
   end
 
   describe "administered_by?/2" do
-
     test "returns false if given invalid arguments" do
       refute Helpers.administered_by?(nil, 2)
     end
@@ -81,7 +80,6 @@ defmodule CodeCorps.Policy.HelpersTest do
   end
 
   describe "contributed_by?/2" do
-
     test "returns false if given invalid arguments" do
       refute Helpers.contributed_by?(nil, 2)
     end
@@ -133,6 +131,27 @@ defmodule CodeCorps.Policy.HelpersTest do
     end
   end
 
+  describe "get_message/1" do
+    test "should return message of a map" do
+      message = insert(:message)
+      result = Helpers.get_message(%{"message_id" => message.id})
+      assert result.id == message.id
+    end
+
+    test "should return message of a Conversation" do
+      message = insert(:message)
+      conversation = insert(:conversation, message: message)
+      result = Helpers.get_message(conversation)
+      assert result.id == message.id
+    end
+
+    test "should return message of a Changeset" do
+      message = insert(:message)
+      changeset = %Changeset{changes: %{message_id: message.id}}
+      result = Helpers.get_message(changeset)
+      assert result.id == message.id
+    end
+  end
 
   describe "get_project/1" do
     test "return project if the project_id is defined on the struct" do
@@ -219,5 +238,4 @@ defmodule CodeCorps.Policy.HelpersTest do
       refute Helpers.task_authored_by?(task, other_user)
     end
   end
-
 end

test/lib/code_corps/messages/messages_test.exs

@@ -282,4 +282,14 @@ defmodule CodeCorps.MessagesTest do
       assert other_conversation_started_by_admin_with_reply.id in result_ids
     end
   end
+
+  describe "get_conversation/1" do
+    test "gets a single conversation" do
+      conversation = insert(:conversation)
+
+      result = Messages.get_conversation(conversation.id)
+
+      assert result.id == conversation.id
+    end
+  end
 end

test/lib/code_corps/policy/conversation_test.exs

@@ -1,7 +1,7 @@
 defmodule CodeCorps.Policy.ConversationTest do
   use CodeCorps.PolicyCase
 
-  import CodeCorps.Policy.Conversation, only: [scope: 2]
+  import CodeCorps.Policy.Conversation, only: [scope: 2, show?: 2]
 
   alias CodeCorps.{Conversation, Repo}
 
@@ -71,4 +71,46 @@ defmodule CodeCorps.Policy.ConversationTest do
       refute some_other_conversation.id in result_ids
     end
   end
+
+  describe "show?" do
+    test "returns true when user is the target" do
+      user = insert(:user)
+      message = insert(:message)
+      conversation = insert(:conversation, message: message, user: user)
+
+      assert show?(user, conversation)
+    end
+
+    test "returns false when user is a pending project member" do
+      %{project: project, user: user} = insert(:project_user, role: "pending")
+      message = insert(:message, project: project)
+      conversation = insert(:conversation, message: message)
+
+      refute show?(user, conversation)
+    end
+
+    test "returns false when user is a project contributor" do
+      %{project: project, user: user} = insert(:project_user, role: "contributor")
+      message = insert(:message, project: project)
+      conversation = insert(:conversation, message: message)
+
+      refute show?(user, conversation)
+    end
+
+    test "returns true when user is a project admin" do
+      %{project: project, user: user} = insert(:project_user, role: "admin")
+      message = insert(:message, project: project)
+      conversation = insert(:conversation, message: message)
+
+      assert show?(user, conversation)
+    end
+
+    test "returns true when user is project owner" do
+      %{project: project, user: user} = insert(:project_user, role: "owner")
+      message = insert(:message, project: project)
+      conversation = insert(:conversation, message: message)
+
+      assert show?(user, conversation)
+    end
+  end
 end

test/lib/code_corps_web/controllers/conversation_controller_test.exs

@@ -30,4 +30,27 @@ defmodule CodeCorpsWeb.ConversationControllerTest do
       |> assert_ids_from_response([conversation_1.id, conversation_2.id])
     end
   end
+
+  describe "show" do
+    @tag :authenticated
+    test "shows chosen resource", %{conn: conn, current_user: user} do
+      conversation = insert(:conversation, user: user)
+
+      conn
+      |> request_show(conversation)
+      |> json_response(200)
+      |> assert_id_from_response(conversation.id)
+    end
+
+    test "renders 401 when unauthenticated", %{conn: conn} do
+      conversation = insert(:conversation)
+      assert conn |> request_show(conversation) |> json_response(401)
+    end
+
+    @tag :authenticated
+    test "renders 403 when unauthorized", %{conn: conn} do
+      conversation = insert(:conversation)
+      assert conn |> request_show(conversation) |> json_response(403)
+    end
+  end
 end