Get the command name from the file path of the first command-line argument.

2 files changed, 29 insertions, 3 deletions

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index 63e4eb1f..841d8f4a 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -404,9 +404,11 @@ class CoverageScript(object):
 
         self.coverage = None
 
-        self.program_name = os.path.basename(sys.argv[0])
-        if self.program_name == '__main__.py':
-            self.program_name = 'coverage'
+        program_path = sys.argv[0]
+        if program_path.endswith(os.path.sep + '__main__.py'):
+            # The path is the main module of a package; get that path instead.
+            program_path = os.path.dirname(program_path)
+        self.program_name = os.path.basename(program_path)
         if env.WINDOWS:
             # entry_points={'console_scripts':...} on Windows makes files
             # called coverage.exe, coverage3.exe, and coverage-3.5.exe. These
diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
index 2378887a..d7b5d307 100644
--- a/tests/test_cmdline.py
+++ b/tests/test_cmdline.py
@@ -642,6 +642,30 @@ class CmdLineStdoutTest(BaseCmdLineTest):
             self.assertIn("without C extension", out)
         self.assertLess(out.count("\n"), 4)
 
+    def test_help_contains_command_name(self):
+        """ Command name should be present in help output. """
+        fake_command_path = "lorem/ipsum/dolor"
+        expected_command_name = "dolor"
+        fake_argv = [fake_command_path, "sit", "amet"]
+        with mock.patch.object(sys, 'argv', new=fake_argv):
+            self.command_line("help")
+        self.assertIn(expected_command_name, out)
+
+    def test_help_contains_command_name_from_package(self):
+        """
+        Command package name should be present in help output.
+
+        When the main module is actually a package's `__main__` module, the resulting command line
+        has the `__main__.py` file's patch as the command name. Instead, the command name should be
+        derived from the package name.
+        """
+        fake_command_path = "lorem/ipsum/dolor/__main__.py"
+        expected_command_name = "dolor"
+        fake_argv = [fake_command_path, "sit", "amet"]
+        with mock.patch.object(sys, 'argv', new=fake_argv):
+            self.command_line("help")
+        self.assertIn(expected_command_name, out)
+
     def test_help(self):
         self.command_line("help")
         out = self.stdout()