Merge pull request #1113 from nedbat/nedbat/capsys

More unittest removal

1 files changed, 70 insertions, 0 deletions

diff --git a/tests/mixins.py b/tests/mixins.py
new file mode 100644
index 00000000..ab0623c0
--- /dev/null
+++ b/tests/mixins.py
@@ -0,0 +1,70 @@
+# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt
+
+"""
+Test class mixins
+
+Some of these are transitional while working toward pure-pytest style.
+"""
+
+import functools
+import types
+
+import pytest
+
+from coverage.backunittest import unittest
+from coverage.misc import StopEverything
+
+
+def convert_skip_exceptions(method):
+    """A decorator for test methods to convert StopEverything to SkipTest."""
+    @functools.wraps(method)
+    def _wrapper(*args, **kwargs):
+        try:
+            result = method(*args, **kwargs)
+        except StopEverything:
+            raise unittest.SkipTest("StopEverything!")
+        return result
+    return _wrapper
+
+
+class SkipConvertingMetaclass(type):
+    """Decorate all test methods to convert StopEverything to SkipTest."""
+    def __new__(cls, name, bases, attrs):
+        for attr_name, attr_value in attrs.items():
+            if attr_name.startswith('test_') and isinstance(attr_value, types.FunctionType):
+                attrs[attr_name] = convert_skip_exceptions(attr_value)
+
+        return super(SkipConvertingMetaclass, cls).__new__(cls, name, bases, attrs)
+
+
+StopEverythingMixin = SkipConvertingMetaclass('StopEverythingMixin', (), {})
+
+
+class StdStreamCapturingMixin:
+    """
+    Adapter from the pytest capsys fixture to more convenient methods.
+
+    This doesn't also output to the real stdout, so we probably want to move
+    to "real" capsys when we can use fixtures in test methods.
+
+    Once you've used one of these methods, the capturing is reset, so another
+    invocation will only return the delta.
+
+    """
+    @pytest.fixture(autouse=True)
+    def _capcapsys(self, capsys):
+        """Grab the fixture so our methods can use it."""
+        self.capsys = capsys
+
+    def stdouterr(self):
+        """Returns (out, err), two strings for stdout and stderr."""
+        return self.capsys.readouterr()
+
+    def stdout(self):
+        """Returns a string, the captured stdout."""
+        return self.capsys.readouterr().out
+
+    def stderr(self):
+        """Returns a string, the captured stderr."""
+        return self.capsys.readouterr().err