Support directories on the 'coverage run' command line. #252

8 files changed, 58 insertions, 24 deletions

diff --git a/AUTHORS.txt b/AUTHORS.txt
index d484edf1..1508d45d 100644
--- a/AUTHORS.txt
+++ b/AUTHORS.txt
@@ -26,6 +26,7 @@ David Christian
 David Stanek
 Detlev Offenbach
 Devin Jeanpierre
+Dmitry Trofimov
 Eduardo Schettino
 Edward Loper
 Geoff Bache
diff --git a/CHANGES.txt b/CHANGES.txt
index 492e831c..45a264a2 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -27,6 +27,9 @@ Latest
 - In parallel mode, ``coverage erase`` will now delete all of the data files,
   fixing `issue 262`_.
 
+- Coverage.py now accepts a directory name for ``coverage run`` and will run a
+  ``__main__.py`` found there, just like Python will.  Fixes `issue 252`_.
+
 - The XML report now includes a ``missing-branches`` attribute.  Thanks, Steve
   Peak.  This is not a part of the Cobertura DTD, so the XML report no longer
   references the DTD.
@@ -60,6 +63,7 @@ Latest
   support, finishing up `issue 387`_.
 
 .. _issue 236: https://bitbucket.org/ned/coveragepy/issues/236/pickles-are-bad-and-you-should-feel-bad
+.. _issue 252: https://bitbucket.org/ned/coveragepy/issues/252/coverage-wont-run-a-program-with
 .. _issue 262: https://bitbucket.org/ned/coveragepy/issues/262/when-parallel-true-erase-should-erase-all
 .. _issue 275: https://bitbucket.org/ned/coveragepy/issues/275/refer-consistently-to-project-as-coverage
 .. _issue 313: https://bitbucket.org/ned/coveragepy/issues/313/add-license-file-containing-2-3-or-4
diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index fc40e619..aeb74bd5 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -5,7 +5,6 @@
 
 import glob
 import optparse
-import os
 import sys
 import traceback
 
@@ -560,19 +559,14 @@ class CoverageScript(object):
             if not options.append:
                 self.coverage.erase()
 
-        # Set the first path element properly.
-        old_path0 = sys.path[0]
-
         # Run the script.
         self.coverage.start()
         code_ran = True
         try:
             if options.module:
-                sys.path[0] = ''
                 self.run_python_module(args[0], args)
             else:
                 filename = args[0]
-                sys.path[0] = os.path.abspath(os.path.dirname(filename))
                 self.run_python_file(filename, args)
         except NoSource:
             code_ran = False
@@ -584,9 +578,6 @@ class CoverageScript(object):
                     self.coverage.combine(data_paths=[self.coverage.config.data_file])
                 self.coverage.save()
 
-            # Restore the old path
-            sys.path[0] = old_path0
-
         return OK
 
     def do_debug(self, args):
diff --git a/coverage/execfile.py b/coverage/execfile.py
index d1158b51..1845f8d7 100644
--- a/coverage/execfile.py
+++ b/coverage/execfile.py
@@ -108,10 +108,10 @@ def run_python_module(modulename, args):
 
     pathname = os.path.abspath(pathname)
     args[0] = pathname
-    run_python_file(pathname, args, package=packagename, modulename=modulename)
+    run_python_file(pathname, args, package=packagename, modulename=modulename, path0="")
 
 
-def run_python_file(filename, args, package=None, modulename=None):
+def run_python_file(filename, args, package=None, modulename=None, path0=None):
     """Run a Python file as if it were the main program on the command line.
 
     `filename` is the path to the file to execute, it need not be a .py file.
@@ -121,6 +121,9 @@ def run_python_file(filename, args, package=None, modulename=None):
 
     `modulename` is the name of the module the file was run as.
 
+    `path0` is the value to put into sys.path[0].  If it's None, then this
+    function will decide on a value.
+
     """
     if modulename is None and sys.version_info >= (3, 3):
         modulename = '__main__'
@@ -142,7 +145,10 @@ def run_python_file(filename, args, package=None, modulename=None):
     sys.argv = args
 
     if os.path.isdir(filename):
-        # in directory we should look for __main__ module
+        # Running a directory means running the __main__.py file in that
+        # directory.
+        my_path0 = filename
+
         for ext in [".py", ".pyc", ".pyo"]:
             try_filename = os.path.join(filename, "__main__" + ext)
             if os.path.exists(try_filename):
@@ -150,6 +156,12 @@ def run_python_file(filename, args, package=None, modulename=None):
                 break
         else:
             raise NoSource("Can't find '__main__' module in '%s'" % filename)
+    else:
+        my_path0 = os.path.abspath(os.path.dirname(filename))
+
+    # Set sys.path correctly.
+    old_path0 = sys.path[0]
+    sys.path[0] = path0 if path0 is not None else my_path0
 
     try:
         # Make a code object somehow.
@@ -181,11 +193,10 @@ def run_python_file(filename, args, package=None, modulename=None):
 
             raise ExceptionDuringRun(typ, err, tb.tb_next)
     finally:
-        # Restore the old __main__
+        # Restore the old __main__, argv, and path.
         sys.modules['__main__'] = old_main_mod
-
-        # Restore the old argv and path
         sys.argv = old_argv
+        sys.path[0] = old_path0
 
 
 def make_code_from_py(filename):
diff --git a/tests/test_execfile.py b/tests/test_execfile.py
index 2533f81d..a3ea1153 100644
--- a/tests/test_execfile.py
+++ b/tests/test_execfile.py
@@ -86,14 +86,17 @@ class RunFileTest(CoverageTest):
             run_python_file("xyzzy.py", [])
 
     def test_directory_with_main(self):
-        directory_with_main = os.path.join(HERE, "with_main")
-        run_python_file(directory_with_main, [directory_with_main])
-        self.assertEqual(self.stdout(), "1\n")
+        self.make_file("with_main/__main__.py", """\
+            print("I am __main__")
+            """)
+        run_python_file("with_main", ["with_main"])
+        self.assertEqual(self.stdout(), "I am __main__\n")
 
     def test_directory_without_main(self):
-        with self.assertRaises(NoSource):
-            directory_with_main = os.path.join(HERE, "with_main", "without")
-            run_python_file(directory_with_main, [directory_with_main])
+        self.make_file("without_main/__init__.py", "")
+        with self.assertRaisesRegex(NoSource, "Can't find '__main__' module in 'without_main'"):
+            run_python_file("without_main", ["without_main"])
+
 
 class RunPycFileTest(CoverageTest):
     """Test cases for `run_python_file`."""
diff --git a/tests/test_process.py b/tests/test_process.py
index 7c8b0c2d..fcd88827 100644
--- a/tests/test_process.py
+++ b/tests/test_process.py
@@ -7,6 +7,7 @@
 import glob
 import os
 import os.path
+import re
 import sys
 import textwrap
 
@@ -387,6 +388,26 @@ class ProcessTest(CoverageTest):
         out_py = self.run_command("python -m tests.try_execfile")
         self.assertMultiLineEqual(out_cov, out_py)
 
+    def test_coverage_run_dir_is_like_python_dir(self):
+        tryfile = os.path.join(HERE, "try_execfile.py")
+        with open(tryfile) as f:
+            self.make_file("with_main/__main__.py", f.read())
+        out_cov = self.run_command("coverage run with_main")
+        out_py = self.run_command("python with_main")
+
+        # The coverage.py results are not identical to the Python results, and
+        # I don't know why.  For now, ignore those failures. If someone finds
+        # a real problem with the discrepancies, we can work on it some more.
+        ignored = r"__file__|__loader__|__package__"
+        # PyPy includes the current directory in the path when running a
+        # directory, while CPython and coverage.py do not.  Exclude that from
+        # the comparison also...
+        if env.PYPY:
+            ignored += "|"+re.escape(os.getcwd())
+        out_cov = remove_matching_lines(out_cov, ignored)
+        out_py = remove_matching_lines(out_py, ignored)
+        self.assertMultiLineEqual(out_cov, out_py)
+
     def test_coverage_run_dashm_equal_to_doubledashsource(self):
         """regression test for #328
 
@@ -995,3 +1016,9 @@ class ProcessStartupWithSourceTest(ProcessCoverageMixin, CoverageTest):
 
     def test_script_pkg_sub(self):
         self.assert_pth_and_source_work_together('', 'pkg', 'sub')
+
+
+def remove_matching_lines(text, pat):
+    """Return `text` with all lines matching `pat` removed."""
+    lines = [l for l in text.splitlines(True) if not re.search(pat, l)]
+    return "".join(lines)
diff --git a/tests/with_main/__main__.py b/tests/with_main/__main__.py
deleted file mode 100644
index e7a4e4f9..00000000
--- a/tests/with_main/__main__.py
+++ /dev/null
@@ -1,2 +0,0 @@
-x = 1
-print(x)
\ No newline at end of file
diff --git a/tests/with_main/without/__init__.py b/tests/with_main/without/__init__.py
deleted file mode 100644
index 595e3818..00000000
--- a/tests/with_main/without/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-__author__ = 'traff'