Add API documentation

Add docstrings and sphinx structure to expose them through the developer
docs for the library.

Also add a 'docs' target in tox.ini to make building the documentation
locally easier.

Remove the nearly useless usage.rst file.

Turn on the pbr flag to treat doc build warnings as errors.

Closes-bug: #1329952

Change-Id: I274a4144edf4efe9ed786e220e40003fda6f99e0

6 files changed, 70 insertions, 14 deletions

diff --git a/doc/source/api.rst b/doc/source/api.rst
new file mode 100644
index 0000000..fc873d4
--- /dev/null
+++ b/doc/source/api.rst
@@ -0,0 +1,23 @@
+=====
+ API
+=====
+
+oslotest.base
+=============
+
+.. automodule:: oslotest.base
+
+.. autoclass:: oslotest.base.BaseTestCase
+   :members:
+
+oslotest.mockpatch
+==================
+
+.. automodule:: oslotest.mockpatch
+   :members:
+
+oslotest.moxstubout
+===================
+
+.. automodule:: oslotest.moxstubout
+   :members:
diff --git a/doc/source/index.rst b/doc/source/index.rst
index 97f5fd8..1bdc6d5 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -14,7 +14,7 @@ Contents:
 
    readme
    installation
-   usage
+   api
    contributing
 
 Indices and tables
diff --git a/doc/source/usage.rst b/doc/source/usage.rst
deleted file mode 100644
index a8ccdc4..0000000
--- a/doc/source/usage.rst
+++ /dev/null
@@ -1,13 +0,0 @@
-========
-Usage
-========
-
-To use  in a project::
-
-    from oslotest import base
-
-
-    class MyTest(base.BaseTestCase):
-
-        def test_something(self):
-            self.assertTrue(True)
diff --git a/oslotest/base.py b/oslotest/base.py
index f84e810..f9c4b92 100644
--- a/oslotest/base.py
+++ b/oslotest/base.py
@@ -28,6 +28,38 @@ _LOG_FORMAT = "%(levelname)8s [%(name)s] %(message)s"
 
 
 class BaseTestCase(testtools.TestCase):
+    """Base class for unit test classes.
+
+    If the environment variable ``OS_TEST_TIMEOUT`` is set to an
+    integer value, a timer is configured to control how long
+    individual test cases can run. This lets tests fail for taking too
+    long, and prevents deadlocks from completely hanging test runs.
+
+    If the environment variable ``OS_STDOUT_CAPTURE`` is set, a fake
+    stream replaces ``sys.stdout`` so the test can look at the output
+    it produces.
+
+    If the environment variable ``OS_STDERR_CAPTURE`` is set, a fake
+    stream replaces ``sys.stderr`` so the test can look at the output
+    it produces.
+
+    If the environment variable ``OS_DEBUG`` is set to a true value,
+    debug logging is enabled.
+
+    If the environment variable ``OS_LOG_CAPTURE`` is set to a true
+    value, a logging fixture is installed to capture the log output.
+
+    Uses the fixtures_ module to configure a :class:`NestedTempFile`
+    to ensure that all temporary files are created in an isolated
+    location.
+
+    Uses the fixtures_ module to configure a :class:`TempHomeDir` to
+    change the ``HOME`` environment variable to point to a temporary
+    location.
+
+    .. _fixtures: https://pypi.python.org/pypi/fixtures
+
+    """
 
     def setUp(self):
         super(BaseTestCase, self).setUp()
@@ -73,6 +105,14 @@ class BaseTestCase(testtools.TestCase):
             logging.basicConfig(format=_LOG_FORMAT, level=level)
 
     def create_tempfiles(self, files, ext='.conf'):
+        """Safely create temporary files.
+
+        :param files: Sequence of tuples containing (filename, file_contents).
+        :type files: list of tuple
+        :param ext: File name extension for the temporary file.
+        :type ext: str
+        :return: A list of str with the names of the files created.
+        """
         tempfiles = []
         for (basename, contents) in files:
             if not os.path.isabs(basename):
diff --git a/setup.cfg b/setup.cfg
index 8f8f2ef..db254a7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -34,3 +34,6 @@ all_files = 1
 
 [upload_sphinx]
 upload-dir = doc/build/html
+
+[pbr]
+warnerrors = true
diff --git a/tox.ini b/tox.ini
index b9dc298..a1da19c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -23,6 +23,9 @@ commands =
 [testenv:venv]
 commands = {posargs}
 
+[testenv:docs]
+commands = python setup.py build_sphinx
+
 [flake8]
 show-source = True
 exclude = .tox,dist,doc,*.egg,build