Refactor helpers from UserTask and TaskSkill into Helpers.Policy

lib/code_corps/helpers/policy.ex

@@ -6,7 +6,11 @@ defmodule CodeCorps.Helpers.Policy do
 
   import Ecto.Query
 
-  alias CodeCorps.{Organization, OrganizationMembership, Project, Repo, StripeConnectAccount, User}
+  alias CodeCorps.{
+    Organization, OrganizationMembership,
+    Project, Repo, StripeConnectAccount,
+    TaskSkill, Task, User, UserTask
+  }
   alias Ecto.Changeset
 
   @doc """
@@ -15,6 +19,7 @@ defmodule CodeCorps.Helpers.Policy do
 
   Returns `CodeCorps.OrganizationMembership`
   """
+  @spec get_membership(nil | Changeset.t | Project.t | Organization.t | StripeConnectAccount.t, User.t) :: nil | OrganizationMembership.t
   def get_membership(nil, %User{}), do: nil
   def get_membership(%Changeset{changes: %{organization_id: organization_id}}, %User{id: user_id}), do: do_get_membership(organization_id, user_id)
   def get_membership(%Project{organization_id: organization_id}, %User{id: user_id}), do: do_get_membership(organization_id, user_id)
@@ -31,6 +36,7 @@ defmodule CodeCorps.Helpers.Policy do
 
   Returns `CodeCorps.Project`
   """
+  @spec get_project(struct | Changeset.t | any) :: Project.t
   def get_project(%{project_id: project_id}), do: Project |> Repo.get(project_id)
   def get_project(%Changeset{changes: %{project_id: project_id}}), do: Project |> Repo.get(project_id)
   def get_project(_), do: nil
@@ -40,25 +46,45 @@ defmodule CodeCorps.Helpers.Policy do
 
   Returns `:string`
   """
+  @spec get_role(nil | OrganizationMembership.t | Changeset.t) :: String.t
   def get_role(nil), do: nil
   def get_role(%OrganizationMembership{role: role}), do: role
   def get_role(%Changeset{} = changeset), do: changeset |> Changeset.get_field(:role)
 
   @doc """
   Determines if provided string is equal to "owner"
   """
+  @spec owner?(String.t) :: boolean
   def owner?("owner"), do: true
   def owner?(_), do: false
 
   @doc """
   Determines if provided string is equal to one of `["admin", "owner"]`
   """
+  @spec admin_or_higher?(String.t) :: boolean
   def admin_or_higher?(role) when role in ["admin", "owner"], do: true
   def admin_or_higher?(_), do: false
 
   @doc """
   Determines if provided string is equal to one of `["contributor", "admin", "owner"]`
   """
+  @spec contributor_or_higher?(String.t) :: boolean
   def contributor_or_higher?(role) when role in ["contributor", "admin", "owner"], do: true
   def contributor_or_higher?(_), do: false
+
+  @doc """
+  Retrieves task from associated record
+  """
+  @spec get_task(Changeset.t | TaskSkill.t | UserTask.t) :: Task.t
+  def get_task(%TaskSkill{task_id: task_id}), do: Repo.get(Task, task_id)
+  def get_task(%UserTask{task_id: task_id}), do: Repo.get(Task, task_id)
+  def get_task(%Changeset{changes: %{task_id: task_id}}), do: Repo.get(Task, task_id)
+
+  @doc """
+  Determines if the provided task was authored by the provided user
+  """
+  @spec task_authored_by?(Task.t, User.t) :: boolean
+  def task_authored_by?(%Task{user_id: author_id}, %User{id: user_id}), do: user_id == author_id
+
+
 end

web/policies/task_skill_policy.ex

@@ -3,17 +3,25 @@ defmodule CodeCorps.TaskSkillPolicy do
   Represents an authorization policy for performing actions on TaskSkill records.
   Used to authorize a controller action.
   """
+
   import CodeCorps.Helpers.Policy,
-    only: [get_project: 1, get_membership: 2, get_role: 1, contributor_or_higher?: 1]
+    only: [
+      contributor_or_higher?: 1,
+      get_membership: 2,
+      get_project: 1,
+      get_role: 1,
+      get_task: 1,
+      task_authored_by?: 2
+    ]
 
-  alias CodeCorps.{Repo, Task, TaskSkill, User}
+  alias CodeCorps.{TaskSkill, User}
   alias Ecto.Changeset
 
   @spec create?(User.t, Changeset.t) :: boolean
   def create?(%User{} = user, %Changeset{} = changeset) do
     cond do
       changeset |> get_task |> get_project |> get_membership(user) |> get_role |> contributor_or_higher? -> true
-      changeset |> get_task |> authored_by?(user) -> true
+      changeset |> get_task |> task_authored_by?(user) -> true
       true -> false
     end
   end
@@ -22,13 +30,8 @@ defmodule CodeCorps.TaskSkillPolicy do
   def delete?(%User{} = user, %TaskSkill{} = task_skill) do
     cond do
       task_skill |> get_task |> get_project |> get_membership(user) |> get_role |> contributor_or_higher? -> true
-      task_skill |> get_task |> authored_by?(user) -> true
+      task_skill |> get_task |> task_authored_by?(user) -> true
       true -> false
     end
   end
-
-  defp get_task(%TaskSkill{task_id: task_id}), do: Repo.get(Task, task_id)
-  defp get_task(%Changeset{changes: %{task_id: task_id}}), do: Repo.get(Task, task_id)
-
-  defp authored_by?(%Task{user_id: author_id}, %User{id: user_id}), do: user_id == author_id
 end

web/policies/user_task_policy.ex

@@ -4,16 +4,23 @@ defmodule CodeCorps.UserTaskPolicy do
   Used to authorize a controller action.
   """
   import CodeCorps.Helpers.Policy,
-    only: [get_project: 1, get_membership: 2, get_role: 1, contributor_or_higher?: 1]
+    only: [
+      contributor_or_higher?: 1,
+      get_membership: 2,
+      get_project: 1,
+      get_role: 1,
+      get_task: 1,
+      task_authored_by?: 2
+    ]
 
-  alias CodeCorps.{Repo, Task, UserTask, User}
+  alias CodeCorps.{User, UserTask}
   alias Ecto.Changeset
 
   @spec create?(User.t, Changeset.t) :: boolean
   def create?(%User{} = user, %Changeset{} = changeset) do
     cond do
       changeset |> get_task |> get_project |> get_membership(user) |> get_role |> contributor_or_higher? -> true
-      changeset |> get_task |> authored_by?(user) -> true
+      changeset |> get_task |> task_authored_by?(user) -> true
       true -> false
     end
   end
@@ -22,13 +29,8 @@ defmodule CodeCorps.UserTaskPolicy do
   def delete?(%User{} = user, %UserTask{} = user_task) do
     cond do
       user_task |> get_task |> get_project |> get_membership(user) |> get_role |> contributor_or_higher? -> true
-      user_task |> get_task |> authored_by?(user) -> true
+      user_task |> get_task |> task_authored_by?(user) -> true
       true -> false
     end
   end
-
-  defp get_task(%UserTask{task_id: task_id}), do: Repo.get(Task, task_id)
-  defp get_task(%Changeset{changes: %{task_id: task_id}}), do: Repo.get(Task, task_id)
-
-  defp authored_by?(%Task{user_id: author_id}, %User{id: user_id}), do: user_id == author_id
 end