1 files changed, 96 insertions, 0 deletions
diff --git a/_pytest/recwarn.py b/_pytest/recwarn.py
new file mode 100644
index 0000000000..e2fb2b17e4
--- /dev/null
+++ b/_pytest/recwarn.py
@@ -0,0 +1,96 @@
+""" recording warnings during test function execution. """
+
+import py
+import sys, os
+
+def pytest_funcarg__recwarn(request):
+    """Return a WarningsRecorder instance that provides these methods:
+
+    * ``pop(category=None)``: return last warning matching the category.
+    * ``clear()``: clear list of warnings
+    """
+    if sys.version_info >= (2,7):
+        import warnings
+        oldfilters = warnings.filters[:]
+        warnings.simplefilter('default')
+        def reset_filters():
+            warnings.filters[:] = oldfilters
+        request.addfinalizer(reset_filters)
+    wrec = WarningsRecorder()
+    request.addfinalizer(wrec.finalize)
+    return wrec
+
+def pytest_namespace():
+    return {'deprecated_call': deprecated_call}
+
+def deprecated_call(func, *args, **kwargs):
+    """ assert that calling ``func(*args, **kwargs)``
+    triggers a DeprecationWarning.
+    """
+    warningmodule = py.std.warnings
+    l = []
+    oldwarn_explicit = getattr(warningmodule, 'warn_explicit')
+    def warn_explicit(*args, **kwargs):
+        l.append(args)
+        oldwarn_explicit(*args, **kwargs)
+    oldwarn = getattr(warningmodule, 'warn')
+    def warn(*args, **kwargs):
+        l.append(args)
+        oldwarn(*args, **kwargs)
+
+    warningmodule.warn_explicit = warn_explicit
+    warningmodule.warn = warn
+    try:
+        ret = func(*args, **kwargs)
+    finally:
+        warningmodule.warn_explicit = warn_explicit
+        warningmodule.warn = warn
+    if not l:
+        #print warningmodule
+        __tracebackhide__ = True
+        raise AssertionError("%r did not produce DeprecationWarning" %(func,))
+    return ret
+
+
+class RecordedWarning:
+    def __init__(self, message, category, filename, lineno, line):
+        self.message = message
+        self.category = category
+        self.filename = filename
+        self.lineno = lineno
+        self.line = line
+
+class WarningsRecorder:
+    def __init__(self):
+        warningmodule = py.std.warnings
+        self.list = []
+        def showwarning(message, category, filename, lineno, line=0):
+            self.list.append(RecordedWarning(
+                message, category, filename, lineno, line))
+            try:
+                self.old_showwarning(message, category,
+                    filename, lineno, line=line)
+            except TypeError:
+                # < python2.6
+                self.old_showwarning(message, category, filename, lineno)
+        self.old_showwarning = warningmodule.showwarning
+        warningmodule.showwarning = showwarning
+
+    def pop(self, cls=Warning):
+        """ pop the first recorded warning, raise exception if not exists."""
+        for i, w in enumerate(self.list):
+            if issubclass(w.category, cls):
+                return self.list.pop(i)
+        __tracebackhide__ = True
+        assert 0, "%r not found in %r" %(cls, self.list)
+
+    #def resetregistry(self):
+    #    import warnings
+    #    warnings.onceregistry.clear()
+    #    warnings.__warningregistry__.clear()
+
+    def clear(self):
+        self.list[:] = []
+
+    def finalize(self):
+        py.std.warnings.showwarning = self.old_showwarning