Use metaclass for test generation, works way better for test discovery.

Test - naming, bikeshedding.

tests/unittests/run_tests.py

@@ -0,0 +1,16 @@
+import unittest
+
+if __name__ == '__main__':
+
+    # use the default shared TestLoader instance
+    test_loader = unittest.defaultTestLoader
+
+    # use the basic test runner that outputs to sys.stderr
+    test_runner = unittest.TextTestRunner()
+
+    # automatically discover all tests in the current dir of the form test*.py
+    # NOTE: only works for python 2.7 and later
+    test_suite = test_loader.discover('.')
+
+    # run the test suite
+    test_runner.run(test_suite)

tests/unittests/test_file_output.py

@@ -0,0 +1,50 @@
+"""
+Check if shoebot can create files in all it's different output formats
+and that none are zero bytes long.
+"""
+
+import tempfile
+import unittest
+
+from os import stat, unlink
+from os.path import exists
+
+import shoebot
+
+from shoebot.core import CairoCanvas, CairoImageSink
+from shoebot.data import BezierPath
+from shoebot.grammar import NodeBot
+
+
+FORMATS = ["png", "ps", "pdf", "svg"]
+BOT_CODE = "background(0)"
+
+def run_shoebot_code(code, outputfile):
+    bot = shoebot.create_bot(outputfile=outputfile)
+    bot.run(code)
+    return outputfile
+
+
+class TestFileOutputMeta(type):
+    def __new__(mcs, name, bases, dct):
+        def create_output_test(fmt, name):
+            def test(self):
+                h, fn = tempfile.mkstemp(suffix=".%s" % fmt)
+                run_shoebot_code(BOT_CODE, outputfile=fn)
+                self.assertTrue(exists(fn), "%s was not created" % fn)
+                size_not_zero = stat(fn).st_size != 0
+                self.assertTrue(size_not_zero, "%s is zero bytes." % fn)
+                unlink(fn)
+            return test
+
+        for fmt in FORMATS:
+            test_name = 'test_create_' + fmt
+            dct[test_name] = create_output_test(fmt, name)
+
+        return type.__new__(mcs, name, bases, dct)
+
+class TestSequence(unittest.TestCase):
+    __metaclass__ = TestFileOutputMeta
+
+if __name__ == '__main__':
+    unittest.main()