pytest follow up

[massich]

Migrate the value validation

• assert_equal (nose2pytest) [MRG] nosetests to pytests #310

• assert_almost_equal (or floating point comparison [MRG] nosetests to pytests #310)
  Instead of using the nose2pytest's default transformation which changes assert_almost_equal(a, b, delta[,msg]) into assert abs(a-b) <= delta[, msg], we chose to use the approx helper function that translates to assert a == approx(b, [abs=delta])[, msg]. In this manner:

  + from pytest import approx
  -    assert_equal(score, 0.65025)
  +    assert score == approx(0.65025)

• assert_array_equal

• assert_array_almost_equal

• assert_allclose

Migrate raising checks

• assert_raise [MRG] Migrate raising errors from nose to pytest #321
  Based on the documentation here, assert_raises(ValueError, func, *args, **kwargs ) can become: pytest.raises(ValueError, func, *args, **kwargs ), pytest.raises(ValueError, "func(*args, **kwargs)" ) or with raises(ValueError): func(*args, **kwargs). The first option can be done using find-replace but we latter is preferred for readability. (it has been carried out manually)
  here is an example:

  -    assert_raises(TypeError, Pipeline)
  +    with raises(TypeError):
  +        Pipeline()

• assert_raises_regex [MRG] Migrate raising errors from nose to pytest #321
  See match(regexp) here
  In example:

  -    assert_raises_regex(ValueError, "has to be one of",
  -                        ada.fit_sample, X, Y)
  +    with raises(ValueError, match="has to be one of"):
  +        ada.fit_sample(X, Y)

• assert_raise_message ([MRG] Migrate raising errors from nose to pytest #321: f8ad59e)
  Use assert + regex match.

• assert_warns
  Deprecation warnings are treated different (see this)

• assert_warns_message

• assert_no_warnings

• my_assert (this is a custom assert with in a loop here)

yield

• yield

Set-up and tare-down become fixtures

Other things to migrate

• Update the CI (at master)
• Update Makefiles (at master)

[massich]

assert_array_equal, assert_array_almost_equal, etc belong to numpy not nosetests. So we don't need to translate them. I would like to translate them but they are not supported by numpy.
I'll check whenever is not an array and change it by pytest.

otherwise, the Issue can be closed.

[massich]

assert_allclose can be changed by pytest assert.

imbalanced-learn/imblearn/metrics/tests/test_score_objects.py

Line 38 in a2de53a

assert_allclose(grid.best_score_, 0.92, rtol=R_TOL)

[glemaitre]

addressed by #470