1 files changed, 98 insertions, 0 deletions
diff --git a/setuptools/tests/contexts.py b/setuptools/tests/contexts.py
new file mode 100644
index 00000000..51ce8984
--- /dev/null
+++ b/setuptools/tests/contexts.py
@@ -0,0 +1,98 @@
+import tempfile
+import os
+import shutil
+import sys
+import contextlib
+import site
+import io
+
+import pkg_resources
+
+
+@contextlib.contextmanager
+def tempdir(cd=lambda dir: None, **kwargs):
+    temp_dir = tempfile.mkdtemp(**kwargs)
+    orig_dir = os.getcwd()
+    try:
+        cd(temp_dir)
+        yield temp_dir
+    finally:
+        cd(orig_dir)
+        shutil.rmtree(temp_dir)
+
+
+@contextlib.contextmanager
+def environment(**replacements):
+    """
+    In a context, patch the environment with replacements. Pass None values
+    to clear the values.
+    """
+    saved = dict(
+        (key, os.environ[key])
+        for key in replacements
+        if key in os.environ
+    )
+
+    # remove values that are null
+    remove = (key for (key, value) in replacements.items() if value is None)
+    for key in list(remove):
+        os.environ.pop(key, None)
+        replacements.pop(key)
+
+    os.environ.update(replacements)
+
+    try:
+        yield saved
+    finally:
+        for key in replacements:
+            os.environ.pop(key, None)
+        os.environ.update(saved)
+
+
+@contextlib.contextmanager
+def quiet():
+    """
+    Redirect stdout/stderr to StringIO objects to prevent console output from
+    distutils commands.
+    """
+
+    old_stdout = sys.stdout
+    old_stderr = sys.stderr
+    new_stdout = sys.stdout = io.StringIO()
+    new_stderr = sys.stderr = io.StringIO()
+    try:
+        yield new_stdout, new_stderr
+    finally:
+        new_stdout.seek(0)
+        new_stderr.seek(0)
+        sys.stdout = old_stdout
+        sys.stderr = old_stderr
+
+
+@contextlib.contextmanager
+def save_user_site_setting():
+    saved = site.ENABLE_USER_SITE
+    try:
+        yield saved
+    finally:
+        site.ENABLE_USER_SITE = saved
+
+
+@contextlib.contextmanager
+def save_pkg_resources_state():
+    pr_state = pkg_resources.__getstate__()
+    # also save sys.path
+    sys_path = sys.path[:]
+    try:
+        yield pr_state, sys_path
+    finally:
+        sys.path[:] = sys_path
+        pkg_resources.__setstate__(pr_state)
+
+
+@contextlib.contextmanager
+def suppress_exceptions(*excs):
+    try:
+        yield
+    except excs:
+        pass