Refactor comment deletion and ensure all comment records are deleted

Author: joshsmith

lib/code_corps/github/event/issue_comment/comment_deleter.ex

@@ -1,8 +1,7 @@
 defmodule CodeCorps.GitHub.Sync.Comment do
   alias CodeCorps.{
     GitHub,
-    GithubComment,
-    GitHub.Event.IssueComment.CommentDeleter
+    GithubComment
   }
   alias GitHub.Sync.Comment.Comment, as: CommentCommentSyncer
   alias GitHub.Sync.Comment.GithubComment, as: CommentGithubCommentSyncer
@@ -33,12 +32,13 @@ defmodule CodeCorps.GitHub.Sync.Comment do
 
   @doc """
   When provided a GitHub API payload, it deletes each `Comment` associated to
-  the specified `IssueComment`.
+  the specified `IssueComment` and then deletes the `GithubComment`.
   """
   @spec delete(map, map) :: Multi.t
-  def delete(_changes, payload) do
+  def delete(_, %{"id" => github_id}) do
     Multi.new
-    |> Multi.run(:comments, fn _ -> CommentDeleter.delete_all(payload) end)
+    |> Multi.run(:deleted_comments, fn _ -> CommentCommentSyncer.delete_all(github_id) end)
+    |> Multi.run(:deleted_github_comment, fn _ -> CommentGithubCommentSyncer.delete(github_id) end)
   end
 
   @spec sync_github_comment(GithubIssue.t, map) :: {:ok, GithubComment.t} | {:error, Ecto.Changeset.t}

lib/code_corps/github/sync/comment/comment.ex

@@ -41,6 +41,23 @@ defmodule CodeCorps.GitHub.Sync.Comment.Comment do
     |> ResultAggregator.aggregate
   end
 
+  @doc ~S"""
+  Deletes all `Comment` records related to `GithubComment` using the GitHub ID
+  from a GitHub API comment payload.
+
+  Returns a list of the deleted `Comment` records.
+  """
+  @spec delete_all(String.t) :: {:ok, list(Comment.t)}
+  def delete_all(github_id) do
+    query =
+      from c in Comment,
+        join: gc in GithubComment, on: gc.id == c.github_comment_id, where: gc.github_id == ^github_id
+
+    query
+    |> Repo.delete_all(returning: true)
+    |> (fn {_count, comments} -> {:ok, comments} end).()
+  end
+
   @spec sync(Task.t, GithubComment.t, User.t, map) :: {:ok, Comment.t} | {:error, Changeset.t}
   defp sync(%Task{} = task, %GithubComment{} = github_comment, %User{} = user, %{} = payload) do
     task

lib/code_corps/github/sync/comment/comment/comment.ex

@@ -37,6 +37,22 @@ defmodule CodeCorps.GitHub.Sync.Comment.GithubComment do
     end
   end
 
+  @doc ~S"""
+  Deletes the `GithubComment` record using the GitHub ID from a GitHub API
+  comment payload.
+
+  Returns the deleted `Comment` record or an empty `Comment` record if no such
+  record existed.
+  """
+  @spec delete(String.t) :: {:ok, GithubComment.t}
+  def delete(github_id) do
+    comment = Repo.get_by(GithubComment, github_id: github_id)
+    case comment do
+      nil -> {:ok, %GithubComment{}}
+      _ -> Repo.delete(comment, returning: true)
+    end
+  end
+
   @spec create_comment(map) :: linking_result
   defp create_comment(params) do
     %GithubComment{}

lib/code_corps/github/sync/comment/github_comment/github_comment.ex

@@ -127,6 +127,7 @@ defmodule CodeCorps.GitHub.Sync do
 
   @spec marshall_result(tuple) :: tuple
   defp marshall_result({:ok, %{comments: comments}}), do: {:ok, comments}
+  defp marshall_result({:ok, %{deleted_comments: _, deleted_github_comment: _}}), do: {:ok, nil}
   defp marshall_result({:ok, %{github_pull_request: pull_request}}), do: {:ok, pull_request}
   defp marshall_result({:ok, %{tasks: tasks}}), do: {:ok, tasks}
   defp marshall_result({:error, :repo, :unmatched_project, _steps}), do: {:ok, []}

lib/code_corps/github/sync/sync.ex

@@ -1,6 +1,7 @@
 defmodule CodeCorps.GitHub.Event.IssueCommentTest do
   @moduledoc false
 
+  use CodeCorps.BackgroundProcessingCase
   use CodeCorps.DbAccessCase
 
   import CodeCorps.GitHub.TestHelpers
@@ -76,10 +77,9 @@ defmodule CodeCorps.GitHub.Event.IssueCommentTest do
       github_comment = insert(:github_comment, github_id: github_id, github_issue: github_issue)
       insert(:comment, github_comment: github_comment)
 
-      {:ok, comments} = IssueComment.handle(@payload)
-      assert Enum.count(comments) == 1
+      {:ok, nil} = IssueComment.handle(@payload)
       assert Repo.aggregate(Comment, :count, :id) == 0
-      assert Repo.aggregate(GithubComment, :count, :id) == 1 # FIXME
+      assert Repo.aggregate(GithubComment, :count, :id) == 0
     end
 
     test "returns error if payload is wrong" do

test/lib/code_corps/github/event/issue_comment/comment_deleter_test.exs

@@ -1,6 +1,7 @@
 defmodule CodeCorps.GitHub.Event.IssuesTest do
   @moduledoc false
 
+  use CodeCorps.BackgroundProcessingCase
   use CodeCorps.DbAccessCase
 
   import CodeCorps.GitHub.TestHelpers

test/lib/code_corps/github/event/issue_comment/issue_comment_test.exs

@@ -1,6 +1,7 @@
 defmodule CodeCorps.GitHub.Event.PullRequestTest do
   @moduledoc false
 
+  use CodeCorps.BackgroundProcessingCase
   use CodeCorps.DbAccessCase
 
   import CodeCorps.GitHub.TestHelpers

test/lib/code_corps/github/event/issues/issues_test.exs

@@ -6,12 +6,13 @@ defmodule CodeCorps.GitHub.Sync.Comment.CommentTest do
   import CodeCorps.GitHub.TestHelpers
 
   alias CodeCorps.{
-    Repo,
-    Comment
+    Comment,
+    GithubComment,
+    Repo
   }
   alias CodeCorps.GitHub.Sync.Comment.Comment, as: CommentCommentSyncer
 
-  describe "sync all/3" do
+  describe "sync_all/3" do
     @payload load_event_fixture("issue_comment_created")
 
     test "creates missing, updates existing comments for each project associated with the github repo" do
@@ -77,4 +78,36 @@ defmodule CodeCorps.GitHub.Sync.Comment.CommentTest do
       assert Enum.count(errors) == 1
     end
   end
+
+  describe "delete_all/1" do
+    test "deletes all the Comment records for a GithubComment" do
+      github_comment = insert(:github_comment)
+      comments = insert_list(2, :comment, github_comment: github_comment)
+      insert(:comment)
+
+      comment_ids = Enum.map(comments, &Map.get(&1, :id))
+
+      {:ok, deleted_comments} =
+        github_comment.github_id
+        |> CommentCommentSyncer.delete_all()
+
+      assert Enum.count(deleted_comments) == 2
+      assert Repo.aggregate(Comment, :count, :id) == 1
+      assert Repo.aggregate(GithubComment, :count, :id) == 1
+
+      for deleted_comment <- deleted_comments do
+        assert deleted_comment.id in comment_ids
+      end
+    end
+
+    test "works when there are no Comment records for a GithubComment" do
+      github_comment = insert(:github_comment)
+
+      {:ok, deleted_comments} =
+        github_comment.github_id
+        |> CommentCommentSyncer.delete_all()
+
+      assert Enum.count(deleted_comments) == 0
+    end
+  end
 end