Use pytest.importorskip in tests (#492)

* Use pytest.importorskip and add skip_test_env_var

* Adds changelog entry

Author: jrbourbeau

docs/release.rst

@@ -28,6 +28,9 @@ Upcoming Release
 * Removed support for Python 2.
   By :user:`jhamman`; :issue:`393`, :issue:`470`.
 
+* Updates tests to use ``pytest.importorskip``.
+  By :user:`James Bourbeau <jrbourbeau>`; :issue:`492`
+
 * Update ``DirectoryStore`` to create files with more permissive permissions.
   By :user:`Eduardo Gonzalez <eddienko>` and :user:`James Bourbeau <jrbourbeau>`; :issue:`493`
 

zarr/tests/test_convenience.py

@@ -654,14 +654,14 @@ def test_logging(self):
 
 
 def temp_h5f():
+    h5py = pytest.importorskip("h5py")
     fn = tempfile.mktemp()
     atexit.register(os.remove, fn)
     h5f = h5py.File(fn, mode='w')
     atexit.register(lambda v: v.close(), h5f)
     return h5f
 
 
-@unittest.skipIf(h5py is None, 'h5py is not installed')
 class TestCopyHDF5ToZarr(TestCopy):
 
     def __init__(self, *args, **kwargs):
@@ -672,7 +672,6 @@ def __init__(self, *args, **kwargs):
         self.new_dest = group
 
 
-@unittest.skipIf(h5py is None, 'h5py is not installed')
 class TestCopyZarrToHDF5(TestCopy):
 
     def __init__(self, *args, **kwargs):
@@ -683,7 +682,6 @@ def __init__(self, *args, **kwargs):
         self.new_dest = temp_h5f
 
 
-@unittest.skipIf(h5py is None, 'h5py is not installed')
 class TestCopyHDF5ToHDF5(TestCopy):
 
     def __init__(self, *args, **kwargs):

zarr/tests/test_core.py

@@ -23,16 +23,7 @@
                           LRUStoreCache, NestedDirectoryStore, SQLiteStore,
                           atexit_rmglob, atexit_rmtree, init_array, init_group)
 from zarr.util import buffer_size
-
-try:
-    import azure.storage.blob as asb
-except ImportError:  # pragma: no cover
-    asb = None
-
-
-# also check for environment variables indicating whether tests requiring
-# services should be run
-ZARR_TEST_ABS = os.environ.get('ZARR_TEST_ABS', '0')
+from zarr.tests.util import skip_test_env_var
 
 
 # noinspection PyMethodMayBeStatic
@@ -1404,13 +1395,12 @@ def test_nbytes_stored(self):
         assert expect_nbytes_stored == z.nbytes_stored
 
 
-@pytest.mark.skipif(asb is None or ZARR_TEST_ABS == '0',
-                    reason="azure-blob-storage could not be imported or tests not"
-                           "enabled via environment variable")
+@skip_test_env_var("ZARR_TEST_ABS")
 class TestArrayWithABSStore(TestArray):
 
     @staticmethod
     def absstore():
+        asb = pytest.importorskip("azure.storage.blob")
         blob_client = asb.BlockBlobService(is_emulated=True)
         blob_client.delete_container('test')
         blob_client.create_container('test')
@@ -1737,17 +1727,11 @@ def test_nbytes_stored(self):
         pass  # not implemented
 
 
-try:
-    import bsddb3
-except ImportError:  # pragma: no cover
-    bsddb3 = None
-
-
-@unittest.skipIf(bsddb3 is None, 'bsddb3 is not installed')
 class TestArrayWithDBMStoreBerkeleyDB(TestArray):
 
     @staticmethod
     def create_array(read_only=False, **kwargs):
+        bsddb3 = pytest.importorskip("bsddb3")
         path = mktemp(suffix='.dbm')
         atexit.register(os.remove, path)
         store = DBMStore(path, flag='n', open=bsddb3.btopen)
@@ -1762,17 +1746,11 @@ def test_nbytes_stored(self):
         pass  # not implemented
 
 
-try:
-    import lmdb
-except ImportError:  # pragma: no cover
-    lmdb = None
-
-
-@unittest.skipIf(lmdb is None, 'lmdb is not installed')
 class TestArrayWithLMDBStore(TestArray):
 
     @staticmethod
     def create_array(read_only=False, **kwargs):
+        pytest.importorskip("lmdb")
         path = mktemp(suffix='.lmdb')
         atexit.register(atexit_rmtree, path)
         store = LMDBStore(path, buffers=True)
@@ -1790,11 +1768,11 @@ def test_nbytes_stored(self):
         pass  # not implemented
 
 
-@unittest.skipIf(lmdb is None, 'lmdb is not installed')
 class TestArrayWithLMDBStoreNoBuffers(TestArray):
 
     @staticmethod
     def create_array(read_only=False, **kwargs):
+        pytest.importorskip("lmdb")
         path = mktemp(suffix='.lmdb')
         atexit.register(atexit_rmtree, path)
         store = LMDBStore(path, buffers=False)
@@ -1809,17 +1787,11 @@ def test_nbytes_stored(self):
         pass  # not implemented
 
 
-try:
-    import sqlite3
-except ImportError:  # pragma: no cover
-    sqlite3 = None
-
-
-@unittest.skipIf(sqlite3 is None, 'python built without sqlite')
 class TestArrayWithSQLiteStore(TestArray):
 
     @staticmethod
     def create_array(read_only=False, **kwargs):
+        pytest.importorskip("sqlite3")
         path = mktemp(suffix='.db')
         atexit.register(atexit_rmtree, path)
         store = SQLiteStore(path)

zarr/tests/test_hierarchy.py

@@ -22,16 +22,7 @@
                           atexit_rmtree, group_meta_key, init_array,
                           init_group)
 from zarr.util import InfoReporter
-
-try:
-    import azure.storage.blob as asb
-except ImportError:  # pragma: no cover
-    asb = None
-
-
-# also check for environment variables indicating whether tests requiring
-# services should be run
-ZARR_TEST_ABS = os.environ.get('ZARR_TEST_ABS', '0')
+from zarr.tests.util import skip_test_env_var
 
 
 # noinspection PyStatementEffect
@@ -887,13 +878,12 @@ def create_store():
         return store, None
 
 
-@pytest.mark.skipif(asb is None or ZARR_TEST_ABS == '0',
-                    reason="azure-blob-storage could not be imported or tests not enabled"
-                           "via environment variable")
+@skip_test_env_var("ZARR_TEST_ABS")
 class TestGroupWithABSStore(TestGroup):
 
     @staticmethod
     def create_store():
+        asb = pytest.importorskip("azure.storage.blob")
         blob_client = asb.BlockBlobService(is_emulated=True)
         blob_client.delete_container('test')
         blob_client.create_container('test')
@@ -933,50 +923,32 @@ def create_store():
         return store, None
 
 
-try:
-    import bsddb3
-except ImportError:  # pragma: no cover
-    bsddb3 = None
-
-
-@unittest.skipIf(bsddb3 is None, 'bsddb3 is not installed')
 class TestGroupWithDBMStoreBerkeleyDB(TestGroup):
 
     @staticmethod
     def create_store():
+        bsddb3 = pytest.importorskip("bsddb3")
         path = tempfile.mktemp(suffix='.dbm')
         atexit.register(os.remove, path)
         store = DBMStore(path, flag='n', open=bsddb3.btopen)
         return store, None
 
 
-try:
-    import lmdb
-except ImportError:  # pragma: no cover
-    lmdb = None
-
-
-@unittest.skipIf(lmdb is None, 'lmdb is not installed')
 class TestGroupWithLMDBStore(TestGroup):
 
     @staticmethod
     def create_store():
+        pytest.importorskip("lmdb")
         path = tempfile.mktemp(suffix='.lmdb')
         atexit.register(atexit_rmtree, path)
         store = LMDBStore(path)
         return store, None
 
 
-try:
-    import sqlite3
-except ImportError:  # pragma: no cover
-    sqlite3 = None
-
-
-@unittest.skipIf(sqlite3 is None, 'python built without sqlite')
 class TestGroupWithSQLiteStore(TestGroup):
 
     def create_store(self):
+        pytest.importorskip("sqlite3")
         path = tempfile.mktemp(suffix='.db')
         atexit.register(atexit_rmtree, path)
         store = SQLiteStore(path)