def create(conn, job_control_params) do

Try dumping out what you’re getting in job_control_params here when you run the tests. Does it match what JobControls.create_job_control/1 expects?

I don’t believe it will: create_job_control is called from fixture(:job_control) with parameters shaped like

%{comment: ..., control: ..., value: ...}

but in the tests this code:

    test "renders job_control when data is valid", %{conn: conn} do
      conn = post(conn, Routes.job_control_path(conn, :create), job_control: @create_attrs)

will pass (unless use FarmqWeb, :controller is doing something nonstandard) parameters shaped like:

%{"job_control" => %{"comment" => ..., "control" => ..., "value" => ...}}

cast will ignore parameters it doesn’t understand, so it will filter out ALL the input here.

A typical idiom in controller actions looks like:

  def create(conn, %{"job_control" => job_control_params}) do
    with {:ok, %JobControl{} = job_control} <- JobControls.create_job_control(job_control_params) do

...


  def update(conn, %{"id" => id, "job_control" => job_control_params}) do
    job_control = JobControls.get_job_control!(id)

    with {:ok, %JobControl{} = job_control} <- JobControls.update_job_control(job_control, job_control_params) do