"Cannot begin test transaction because we are already inside one"

Question

我遵循了 this tutorial 并且我的简单测试总是失败并出现此错误

1) test /index returns a list of contacts (WorldNote.ChatsControllerTest)                                             
     test/controllers/chats_controller_test.exs:16                                                                      
     ** (RuntimeError) cannot begin test transaction because we are already inside one                                  
     stacktrace:                                                                                                        
       (ecto) lib/ecto/adapters/sql.ex:321: anonymous fn/6 in Ecto.Adapters.SQL.start_test_transaction/3                
       (ecto) lib/ecto/adapters/sql.ex:615: Ecto.Adapters.SQL.pool_transaction/4                                        
       (ecto) lib/ecto/adapters/sql.ex:314: Ecto.Adapters.SQL.start_test_transaction/3                                  
       test/controllers/chats_controller_test.exs:9: WorldNote.ChatsControllerTest.__ex_unit_setup_0/1                  
       test/controllers/chats_controller_test.exs:1: WorldNote.ChatsControllerTest.__ex_unit__/2

代码很简单

defmodule WorldNote.ChatsControllerTest do
  use ExUnit.Case, async: false
  use Plug.Test
  alias WorldNote.Chats
  alias WorldNote.Repo
  alias Ecto.Adapters.SQL

  setup do
    SQL.begin_test_transaction(Repo)

    on_exit fn ->
      SQL.rollback_test_transaction(Repo)
    end
  end

  test "/index returns a list of contacts" do
    contacts_as_json =
      %Chats{fbid: 1234567890, latitude: 0.0, longitude: 0.0, content: "yo"}
      |> Repo.insert
      |> List.wrap
      |> Poison.encode!

    response = conn(:get, "/api/contacts") |> send_request

    assert response.status == 200
    assert response.resp_body == contacts_as_json
  end

  defp send_request(conn) do
    conn
    |> put_private(:plug_skip_csrf_protection, true)
    |> WorldNote.Endpoint.call([])
  end
end

我用谷歌搜索了整个错误 cannot begin test transaction because we are already inside one。但是找不到任何修复。

PS。我正在使用 Postgresql

Answer 1

您使用的是最新的 Phoenix 吗？如果是这样，它应该已经生成 test/support/conn_case.ex，其中已经包含运行控制器测试所需的所有步骤。您只需要在测试中执行 use YourApp.ConnCase 即可。博客 post 是在测试基础设施到位之前写的。 :)

也就是说，原因很可能是因为 test/test_helper.exs 已经调用了 begin_test_transaction。

"Cannot begin test transaction because we are already inside one"

"Cannot begin test transaction because we are already inside one"

elixir

ecto

phoenix-framework