Testing Elixir

Testing Update

Testing update is a bit of a combination of the testing for the create and read functions. Let’s first look at the function we’re going to test:

testing_ecto/lib/users/users.ex

def update(%User{} = existing_user, update_params) do
  existing_user
  |> User.update_changeset(update_params)
  |> Repo.update()
end

You can see that, like create/1, this function is a very lightweight wrapper around calls to the schema’s changeset function (update_changeset/2 in this case) and then to Repo.update/1. Testing it will be similar, but you’ll need to insert an existing user to be updated by the code. Let’s write our success test first:

describe "update/2" do
  test "success: it updates database and returns the user"  ...