Fix error grouping issue

[odarriba]

The errors are being grouped in a wrong way because a type mismatch comparison was done between the application name and the stacktrace application name.

The fix is to convert the configured application name to a string and be able to compare it with the stacktrace application name.

You can test it putting this script on the root project:

Mix.install([
  {:ecto_sql, "~> 3.0"},
  {:postgrex, "~> 0.1"},
  {:error_tracker, path: "."},
  {:bandit, "~> 1.0"}
])

### ErrorLogger config

Application.put_env(:error_tracker, :repo, Repo)
Application.put_env(:error_tracker, :otp_app, :myapp)
Application.put_env(:error_tracker, :enabled, true)

defmodule AddErrorTracker do
  use Ecto.Migration

  def up, do: ErrorTracker.Migration.up(version: 4)

  def down, do: ErrorTracker.Migration.down(version: 1)
end

### Common config

Application.put_env(:myapp, Repo, database: "mix_install_examples")

defmodule Repo do
  use Ecto.Repo, adapter: Ecto.Adapters.Postgres, otp_app: :myapp
end

defmodule Migration0 do
  use Ecto.Migration

  def change do
    create table("posts") do
      add(:title, :string)
      timestamps(type: :utc_datetime_usec)
    end
  end
end

defmodule Post do
  use Ecto.Schema

  schema "posts" do
    field(:title, :string)
    timestamps(type: :utc_datetime_usec)
  end
end

defmodule Main do
  import Ecto.Query, warn: false

  def migrate do
    Repo.__adapter__().storage_down(Repo.config())
    :ok = Repo.__adapter__().storage_up(Repo.config())
    {:ok, _} = Repo.start_link([])
    Ecto.Migrator.run(Repo, [{0, Migration0}, {1, AddErrorTracker}], :up, all: true, log_migrations_sql: :info)
  end

  def register_app_and_modules do
    :application.load({:application, :myapp, [
      {:description, ~c"My sample application"},
      {:vsn, ~c"0.1.0"},
      {:modules, [Router]},
      {:registered, [Router]},
      {:applications, [:kernel, :stdlib]}
    ]})
  end

  def run_http_server do
    Supervisor.start_link([{Bandit, [plug: Router, port: 1234]}], strategy: :one_for_one)
  end

  def make_requests do
    :inets.start()
    :httpc.request("http://localhost:1234/route1")
    :httpc.request("http://localhost:1234/route2")
  end

  def check_what_was_collected do
    ErrorTracker.Error
    |> Repo.all()
    |> IO.inspect()

    ErrorTracker.Occurrence
    |> Repo.all()
    |> Enum.map(&Enum.take(&1.stacktrace.lines, 2))
    |> IO.inspect()
  end
end

defmodule Router do
  use Plug.Router
  use ErrorTracker.Integrations.Plug

  plug(:match)
  plug(:dispatch)

  get "/route1" do
    Repo.get!(Post, 1)
    send_resp(conn, 200, "Anything")
  end

  get "/route2" do
    Repo.get!(Post, 2)
    send_resp(conn, 200, "Anything")
  end
end

Main.migrate()
Main.register_app_and_modules()
Main.run_http_server()
Main.make_requests()
Main.check_what_was_collected() # <- demonstrates the issue

Process.sleep(:infinity)

This closes #132

[crbelaus]

Amazing! I don't know how we missed that one.