pyspec compiler

pyspec.py

#!/usr/bin/env python

import re

def pyspec(source):
    def translate(lines):
        def name(n):
            return re.sub("_+", "_", re.sub(r"[\s\W]+", "_", n)).strip("_")
        def on_describe(m):
            r"""(\s*)describe\s+("[^"]*"|'[^']*'|[^:]+?)\s*:"""
            return "class %sTest(unittest.TestCase):" % name(m.group(2))
        def on_before(m):
            r"""(\s*)before\s*:"""
            return "def setUp(self):"
        def on_after(m):
            r"""(\s*)after\s*:"""
            return "def tearDown(self):"
        def on_it(m):
            r"""(\s*)it\s+("[^"]*"|'[^']*'|[^:]+?)\s*:"""
            return "def test_that_it_%s(self):" % name(m.group(2))
        def on_should(m):
            r"""(\s*)(.*?)\s+should\s+(==|!=|<=?|>=?|is(?:\s+not)?|(?:not\s+)in)\s+(.*)"""
            return 'assert %s %s %s, "%s should be %s %%r but was %%r" %% (%s, %s)' % (
                m.group(2), m.group(3), m.group(4),
                m.group(2).replace('"', '\\"'), m.group(3), m.group(4), m.group(2))
        def on_pending(m):
            r"""(\s*)pending$"""
            return 'assert False, "not yet implemented"'
        patterns = []
        for n, v in locals().items():
            if n.startswith("on_"):
                patterns.append([re.compile(v.__doc__), v])
        yield "import unittest"
        for line in lines:
            for p, f in patterns:
                m = p.match(line)
                if m:
                    yield "%s%s%s" % (m.group(1), f(m), line[m.end():])
                    break
            else:
                yield line
    import sys
    exec "\n".join(translate(source.splitlines())) in sys._getframe(1).f_globals

def main():
    import sys, unittest
    for name in sys.argv[1:]:
        f = open(name)
        try:
            pyspec(f.read())
        finally:
            f.close()
    unittest.main(argv=sys.argv[:1])    

if __name__ == '__main__':
    main()