pllim · Jul 2, 2020 · Jun 17, 2020 · Jun 17, 2020 · Jun 17, 2020 · Jun 19, 2020
diff --git a/astropy/_erfa/tests/test_erfa.py b/astropy/_erfa/tests/test_erfa.py
@@ -7,7 +7,6 @@
 
 from astropy import _erfa as erfa
 from astropy.time import Time
-from astropy.tests.helper import catch_warnings
 
 
 def test_erfa_wrapper():
@@ -20,13 +19,13 @@ def test_erfa_wrapper():
     ra = np.linspace(0.0, np.pi*2.0, 5)
     dec = np.linspace(-np.pi/2.0, np.pi/2.0, 4)
 
-    aob, zob, hob, dob, rob, eo = erfa.atco13(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, jd, 0.0, 0.0, 0.0, np.pi/4.0, 0.0, 0.0, 0.0, 1014.0, 0.0, 0.0, 0.5)
+    aob, zob, hob, dob, rob, eo = erfa.atco13(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, jd, 0.0, 0.0, 0.0, np.pi/4.0, 0.0, 0.0, 0.0, 1014.0, 0.0, 0.0, 0.5)  # noqa
     assert aob.shape == (121,)
 
-    aob, zob, hob, dob, rob, eo = erfa.atco13(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, jd[0], 0.0, 0.0, 0.0, np.pi/4.0, 0.0, 0.0, 0.0, 1014.0, 0.0, 0.0, 0.5)
+    aob, zob, hob, dob, rob, eo = erfa.atco13(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, jd[0], 0.0, 0.0, 0.0, np.pi/4.0, 0.0, 0.0, 0.0, 1014.0, 0.0, 0.0, 0.5)  # noqa
     assert aob.shape == ()
 
-    aob, zob, hob, dob, rob, eo = erfa.atco13(ra[:, None, None], dec[None, :, None], 0.0, 0.0, 0.0, 0.0, jd[None, None, :], 0.0, 0.0, 0.0, np.pi/4.0, 0.0, 0.0, 0.0, 1014.0, 0.0, 0.0, 0.5)
+    aob, zob, hob, dob, rob, eo = erfa.atco13(ra[:, None, None], dec[None, :, None], 0.0, 0.0, 0.0, 0.0, jd[None, None, :], 0.0, 0.0, 0.0, np.pi/4.0, 0.0, 0.0, 0.0, 1014.0, 0.0, 0.0, 0.5)  # noqa
     (aob.shape) == (5, 4, 121)
 
     iy, im, id, ihmsf = erfa.d2dtf("UTC", 3, jd, 0.0)
@@ -111,30 +110,21 @@ def test_errwarn_reporting():
     erfa.dat(1990, 1, 1, 0.5)
 
     # check warning is raised for a scalar
-    with catch_warnings() as w:
+    with pytest.warns(erfa.ErfaWarning, match=r'.* 1 of "dubious year \(Note 1\)"') as w:
         erfa.dat(100, 1, 1, 0.5)
-        assert len(w) == 1
-        assert w[0].category == erfa.ErfaWarning
-        assert '1 of "dubious year (Note 1)"' in str(w[0].message)
+    assert len(w) == 1
 
     # and that the count is right for a vector.
-    with catch_warnings() as w:
+    with pytest.warns(erfa.ErfaWarning, match=r'.* 2 of "dubious year \(Note 1\)".*') as w:
         erfa.dat([100, 200, 1990], 1, 1, 0.5)
-        assert len(w) == 1
-        assert w[0].category == erfa.ErfaWarning
-        assert '2 of "dubious year (Note 1)"' in str(w[0].message)
+    assert len(w) == 1
 
-    try:
+    with pytest.raises(erfa.ErfaError, match=r'.* 1 of "bad day \(Note 3\)", 1 of "bad month".*'):
         erfa.dat(1990, [1, 34, 2], [1, 1, 43], 0.5)
-    except erfa.ErfaError as e:
-        if '1 of "bad day (Note 3)", 1 of "bad month"' not in e.args[0]:
-            assert False, 'Raised the correct type of error, but wrong message: ' + e.args[0]
 
-    try:
+    with pytest.raises(erfa.ErfaError) as e:
         erfa.dat(200, [1, 34, 2], [1, 1, 43], 0.5)
-    except erfa.ErfaError as e:
-        if 'warning' in e.args[0]:
-            assert False, 'Raised the correct type of error, but there were warnings mixed in: ' + e.args[0]
+    assert 'warning' not in str(e.value), f'Raised the correct type of error, but there were warnings mixed in: {str(e.value)}'  # noqa
 
 
 def test_vector_inouts():

diff --git a/astropy/config/tests/test_configs.py b/astropy/config/tests/test_configs.py
@@ -8,8 +8,6 @@
 
 import pytest
 
-from astropy.tests.helper import catch_warnings
-
 from astropy.config import configuration
 from astropy.config import paths
 from astropy.utils.data import get_pkg_data_filename
@@ -310,11 +308,10 @@ def osraiser(dirnm, linkto, pkgname=None):
 
     # now run the basic tests, and make sure the warning about no astropy
     # is present
-    with catch_warnings(configuration.ConfigurationMissingWarning) as w:
+    with pytest.warns(configuration.ConfigurationMissingWarning,
+                      match='Configuration defaults will be used') as w:
         test_configitem()
     assert len(w) == 1
-    w = w[0]
-    assert 'Configuration defaults will be used' in str(w.message)
 
 
 def test_configitem_setters():
@@ -375,14 +372,14 @@ def setup_class(self):
     def test_alias_read(self):
         from astropy.utils.data import conf
 
-        with catch_warnings() as w:
+        with pytest.warns(
+                AstropyDeprecationWarning,
+                match=r"Config parameter 'name_resolve_timeout' in section "
+                      r"\[coordinates.name_resolve\].*") as w:
             conf.reload()
             assert conf.remote_timeout == 42
 
         assert len(w) == 1
-        assert str(w[0].message).startswith(
-            "Config parameter 'name_resolve_timeout' in section "
-            "[coordinates.name_resolve]")
 
     def teardown_class(self):
         from astropy.utils.data import conf
@@ -417,7 +414,7 @@ def test_warning_move_to_top_level():
     configuration._override_config_file = get_pkg_data_filename('data/deprecated.cfg')
 
     try:
-        with catch_warnings(AstropyDeprecationWarning) as w:
+        with pytest.warns(AstropyDeprecationWarning) as w:
             conf.reload()
             conf.max_lines
         assert len(w) == 1

diff --git a/astropy/coordinates/tests/test_api_ape5.py b/astropy/coordinates/tests/test_api_ape5.py
@@ -16,14 +16,14 @@
 import numpy as np
 from numpy import testing as npt
 
-from astropy.tests.helper import raises, assert_quantity_allclose as assert_allclose
+from astropy.tests.helper import assert_quantity_allclose as assert_allclose
 from astropy import units as u
 from astropy import time
 from astropy import coordinates as coords
 from astropy.units import allclose
 
 try:
-    import scipy  # pylint: disable=W0611
+    import scipy  # pylint: disable=W0611  # noqa
 except ImportError:
     HAS_SCIPY = False
 else:
@@ -78,7 +78,7 @@ def test_representations_api():
     c2 = SphericalRepresentation(lon=[8, 9]*u.hourangle, lat=[5, 6]*u.deg, distance=10*u.kpc)
     assert len(c2.distance) == 2
     # when they can't be broadcast, it is a ValueError (same as Numpy)
-    with raises(ValueError):
+    with pytest.raises(ValueError):
         c2 = UnitSphericalRepresentation(lon=[8, 9, 10]*u.hourangle, lat=[5, 6]*u.deg)
 
     # It's also possible to pass in scalar quantity lists with mixed units. These
@@ -101,7 +101,7 @@ def test_representations_api():
     assert isinstance(c1.distance, Distance)
 
     # but they are read-only, as representations are immutable once created
-    with raises(AttributeError):
+    with pytest.raises(AttributeError):
         c1.lat = Latitude(5, u.deg)
     # Note that it is still possible to modify the array in-place, but this is not
     # sanctioned by the API, as this would prevent things like caching.
@@ -111,7 +111,7 @@ def test_representations_api():
     # coordinates are defined, other conventions can be included as new classes.
     # Later there may be other conventions that we implement - for now just the
     # physics convention, as it is one of the most common cases.
-    c3 = PhysicsSphericalRepresentation(phi=120*u.deg, theta=85*u.deg, r=3*u.kpc)
+    _ = PhysicsSphericalRepresentation(phi=120*u.deg, theta=85*u.deg, r=3*u.kpc)
 
     # first dimension must be length-3 if a lone `Quantity` is passed in.
     c1 = CartesianRepresentation(np.random.randn(3, 100) * u.kpc)
@@ -170,11 +170,11 @@ def test_frame_api():
 
     # the information required to specify the frame is immutable
     J2001 = time.Time('J2001')
-    with raises(AttributeError):
+    with pytest.raises(AttributeError):
         fk5.equinox = J2001
 
     # Similar for the representation data.
-    with raises(AttributeError):
+    with pytest.raises(AttributeError):
         fk5.data = UnitSphericalRepresentation(lon=8*u.hour, lat=5*u.deg)
 
     # There is also a class-level attribute that lists the attributes needed to
@@ -224,7 +224,7 @@ def test_frame_api():
     assert coo3.separation_3d(coo4).kpc == 1.0
 
     # The next example fails because `coo1` and `coo2` don't have distances
-    with raises(ValueError):
+    with pytest.raises(ValueError):
         assert coo1.separation_3d(coo2).kpc == 1.0
 
     # repr/str also shows info, with frame and data
@@ -289,7 +289,7 @@ def test_transform_api():
     assert_allclose(fk5_2.ra, fk5_trans_2.ra, rtol=0, atol=1e-10*u.deg)
 
     # Trying to transforming a frame with no data is of course an error:
-    with raises(ValueError):
+    with pytest.raises(ValueError):
         FK5(equinox=J2001).transform_to(ICRS)
 
     # To actually define a new transformation, the same scheme as in the
@@ -306,8 +306,8 @@ class SomeNewSystem(BaseCoordinateFrame):
 
     @frame_transform_graph.transform(DynamicMatrixTransform, SomeNewSystem, FK5)
     def new_to_fk5(newobj, fk5frame):
-        ot = newobj.obstime
-        eq = fk5frame.equinox
+        _ = newobj.obstime
+        _ = fk5frame.equinox
         # ... build a *cartesian* transform matrix using `eq` that transforms from
         # the `newobj` frame as observed at `ot` to FK5 an equinox `eq`
         matrix = np.eye(3)
@@ -417,8 +417,10 @@ def test_highlevel_api():
     # assert str(m31icrs) == '<SkyCoord (ICRS) RA=10.68471 deg, Dec=41.26875 deg>'
 
     if HAS_SCIPY:
-        cat1 = coords.SkyCoord(ra=[1, 2]*u.hr, dec=[3, 4.01]*u.deg, distance=[5, 6]*u.kpc, frame='icrs')
-        cat2 = coords.SkyCoord(ra=[1, 2, 2.01]*u.hr, dec=[3, 4, 5]*u.deg, distance=[5, 200, 6]*u.kpc, frame='icrs')
+        cat1 = coords.SkyCoord(ra=[1, 2]*u.hr, dec=[3, 4.01]*u.deg,
+                               distance=[5, 6]*u.kpc, frame='icrs')
+        cat2 = coords.SkyCoord(ra=[1, 2, 2.01]*u.hr, dec=[3, 4, 5]*u.deg,
+                               distance=[5, 200, 6]*u.kpc, frame='icrs')
         idx1, sep2d1, dist3d1 = cat1.match_to_catalog_sky(cat2)
         idx2, sep2d2, dist3d2 = cat1.match_to_catalog_3d(cat2)
 

diff --git a/astropy/coordinates/tests/test_distance.py b/astropy/coordinates/tests/test_distance.py
@@ -12,11 +12,10 @@
 from astropy.units import allclose as quantity_allclose
 from astropy.coordinates import Longitude, Latitude, Distance, CartesianRepresentation
 from astropy.coordinates.builtin_frames import ICRS, Galactic
-from astropy.tests.helper import catch_warnings
 from astropy.utils.exceptions import AstropyWarning
 
 try:
-    import scipy  # pylint: disable=W0611
+    import scipy  # pylint: disable=W0611  # noqa
 except ImportError:
     HAS_SCIPY = False
 else:
@@ -51,6 +50,7 @@ def test_distances():
     # 3D position
     c = Galactic(l=158.558650*u.degree, b=-43.350066*u.degree,
                  distance=Distance(12, u.parsec))
+    assert quantity_allclose(c.distance, 12 * u.pc)
 
     # or initialize distances via redshifts - this is actually tested in the
     # function below that checks for scipy. This is kept here as an example
@@ -233,13 +233,11 @@ def test_parallax():
     with pytest.raises(ValueError):
         Distance(parallax=[10, 1, -1] * u.mas)
 
-    with catch_warnings(AstropyWarning) as w:
+    with pytest.warns(AstropyWarning):
         Distance(parallax=-1 * u.mas, allow_negative=True)
-    assert len(w) > 0
 
-    with catch_warnings(AstropyWarning) as w:
+    with pytest.warns(AstropyWarning):
         Distance(parallax=[10, 1, -1] * u.mas, allow_negative=True)
-    assert len(w) > 0
 
 
 def test_distance_in_coordinates():

diff --git a/astropy/coordinates/tests/test_frames.py b/astropy/coordinates/tests/test_frames.py
@@ -6,8 +6,7 @@
 import pytest
 
 from astropy import units as u
-from astropy.tests.helper import (catch_warnings,
-                                  assert_quantity_allclose as assert_allclose)
+from astropy.tests.helper import assert_quantity_allclose as assert_allclose
 from astropy.utils import OrderedDescriptorContainer
 from astropy.utils.exceptions import AstropyWarning
 from astropy.coordinates import representation as r
@@ -821,11 +820,9 @@ def test_represent_as():
     assert isinstance(rep2.differentials['s'], r.CylindricalDifferential)
 
     # single class with positional in_frame_units, verify that warning raised
-    with catch_warnings() as w:
+    with pytest.warns(AstropyWarning, match='argument position') as w:
         icrs.represent_as(r.CylindricalRepresentation, False)
-        assert len(w) == 1
-        assert w[0].category == AstropyWarning
-        assert 'argument position' in str(w[0].message)
+    assert len(w) == 1
 
     # TODO: this should probably fail in the future once we figure out a better
     # workaround for dealing with UnitSphericalRepresentation's with

diff --git a/astropy/coordinates/tests/test_iau_fullstack.py b/astropy/coordinates/tests/test_iau_fullstack.py
@@ -13,7 +13,6 @@
 from astropy.coordinates.builtin_frames.utils import get_jd12
 from astropy.coordinates import EarthLocation
 from astropy.coordinates import SkyCoord
-from astropy.tests.helper import catch_warnings
 from astropy import _erfa as erfa
 from astropy.utils import iers
 from .utils import randomly_sample_sphere
@@ -164,26 +163,19 @@ def test_future_altaz():
     if hasattr(utils, '__warningregistry__'):
         utils.__warningregistry__.clear()
 
-    with catch_warnings() as found_warnings:
-
-        location = EarthLocation(lat=0*u.deg, lon=0*u.deg)
-        t = Time('J2161')
-
-        SkyCoord(1*u.deg, 2*u.deg).transform_to(AltAz(location=location, obstime=t))
+    location = EarthLocation(lat=0*u.deg, lon=0*u.deg)
+    t = Time('J2161')
 
     # check that these message(s) appear among any other warnings.  If tests are run with
     # --remote-data then the IERS table will be an instance of IERS_Auto which is
     # assured of being "fresh".  In this case getting times outside the range of the
     # table does not raise an exception.  Only if using IERS_B (which happens without
     # --remote-data, i.e. for all CI testing) do we expect another warning.
-    messages_to_find = ["Tried to get polar motions for times after IERS data is valid."]
+    with pytest.warns(AstropyWarning, match=r"Tried to get polar motions for "
+                      "times after IERS data is valid.*") as found_warnings:
+        SkyCoord(1*u.deg, 2*u.deg).transform_to(AltAz(location=location, obstime=t))
+
     if isinstance(iers.earth_orientation_table.get(), iers.IERS_B):
-        messages_to_find.append("(some) times are outside of range covered by IERS table.")
-
-    messages_found = [False for _ in messages_to_find]
-    for w in found_warnings:
-        if issubclass(w.category, AstropyWarning):
-            for i, message_to_find in enumerate(messages_to_find):
-                if message_to_find in str(w.message):
-                    messages_found[i] = True
-    assert all(messages_found)
+        messages_found = ["(some) times are outside of range covered by IERS "
+                          "table." in str(w.message) for w in found_warnings]
+        assert any(messages_found)
diff --git a/astropy/coordinates/tests/test_regression.py b/astropy/coordinates/tests/test_regression.py
@@ -6,7 +6,6 @@
 place to live
 """
 
-
 import io
 import copy
 import pytest
@@ -28,7 +27,7 @@
 from astropy.utils import iers
 from astropy.table import Table
 
-from astropy.tests.helper import assert_quantity_allclose, catch_warnings
+from astropy.tests.helper import assert_quantity_allclose
 from .test_matching import HAS_SCIPY
 from astropy.units import allclose as quantity_allclose
 
@@ -209,6 +208,7 @@ def test_regression_futuretimes_4302():
 
     Relevant comment: https://github.com/astropy/astropy/pull/4302#discussion_r44836531
     """
+    from astropy.utils.compat.context import nullcontext
     from astropy.utils.exceptions import AstropyWarning
 
     # this is an ugly hack to get the warning to show up even if it has already
@@ -217,25 +217,22 @@ def test_regression_futuretimes_4302():
     if hasattr(utils, '__warningregistry__'):
         utils.__warningregistry__.clear()
 
-    with catch_warnings() as found_warnings:
-        future_time = Time('2511-5-1')
-        c = CIRS(1*u.deg, 2*u.deg, obstime=future_time)
-        c.transform_to(ITRS(obstime=future_time))
-
     # check that out-of-range warning appears among any other warnings.  If
     # tests are run with --remote-data then the IERS table will be an instance
     # of IERS_Auto which is assured of being "fresh".  In this case getting
     # times outside the range of the table does not raise an exception.  Only
     # if using IERS_B (which happens without --remote-data, i.e. for all CI
     # testing) do we expect another warning.
     if isinstance(iers.earth_orientation_table.get(), iers.IERS_B):
-        saw_iers_warnings = False
-        for w in found_warnings:
-            if issubclass(w.category, AstropyWarning):
-                if '(some) times are outside of range covered by IERS table' in str(w.message):
-                    saw_iers_warnings = True
-                    break
-        assert saw_iers_warnings, 'Never saw IERS warning'
+        ctx = pytest.warns(
+            AstropyWarning,
+            match=r'\(some\) times are outside of range covered by IERS table.*')
+    else:
+        ctx = nullcontext()
+    with ctx:
+        future_time = Time('2511-5-1')
+        c = CIRS(1*u.deg, 2*u.deg, obstime=future_time)
+        c.transform_to(ITRS(obstime=future_time))
 
 
 def test_regression_4996():