Added a 'coverage debug' command to get internal information for diagnosing problems. Also, all commands should at least take -h.

6 files changed, 102 insertions, 13 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 7165ec9f..d9e50f1f 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -25,7 +25,10 @@ Version 3.1, unreleased
 

 - Programs that change directory will still write .coverage files in the

   directory where execution started.  Fixed `issue 24`_.

-  

+

+- Added a "coverage info" command for getting diagnostic information about the

+  coverage.py installation.

+

 .. _issue 11: http://bitbucket.org/ned/coveragepy/issue/11

 .. _issue 12: http://bitbucket.org/ned/coveragepy/issue/12

 .. _issue 13: http://bitbucket.org/ned/coveragepy/issue/13

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index accade5b..d421aabe 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -199,7 +199,7 @@ CMDS = {
             "missed with !."
         ),
 
-    'help': CmdOptionParser("help",
+    'help': CmdOptionParser("help", [Opts.help],
         usage = "[command]",
         description = "Describe how to use coverage.py"
         ),
@@ -217,14 +217,22 @@ CMDS = {
             "executed, excluded, and missed lines."
         ),
     
-    'combine': CmdOptionParser("combine",
+    'combine': CmdOptionParser("combine", [Opts.help],
         usage = " ",
         description = "Combine data from multiple coverage files collected "
             "with 'run -p'.  The combined results are stored into a single "
             "file representing the union of the coverage."
         ),
 
-    'erase': CmdOptionParser("erase",
+    'debug': CmdOptionParser("debug", [Opts.help],
+        usage = "<topic>",
+        description = "Display information the internals of coverage.py, "
+            "for diagnosing problems. "
+            "Topics are 'data' to show a summary of the data collected in "
+            ".coverage, or 'sys' to show installation information."
+        ),
+
+    'erase': CmdOptionParser("erase", [Opts.help],
         usage = " ",
         description = "Erase previously collected coverage data."
         ),
@@ -371,6 +379,7 @@ class CoverageScript:
             'execute' in options.actions or
             'annotate' in options.actions or
             'html' in options.actions or
+            'debug' in options.actions or
             'report' in options.actions or
             'xml' in options.actions
             )
@@ -389,6 +398,35 @@ class CoverageScript:
             timid = options.timid,
             )
 
+        if 'debug' in options.actions:
+            if not args:
+                self.help_fn("What information would you like: data, sys?")
+                return ERR
+            for info in args:
+                if info == 'sys':
+                    print("-- sys ----------------------------------------")
+                    for label, info in self.coverage.sysinfo():
+                        if isinstance(info, list):
+                            print("%15s:" % label)
+                            for e in info:
+                                print("%15s  %s" % ("", e))
+                        else:
+                            print("%15s: %s" % (label, info))
+                elif info == 'data':
+                    print("-- data ---------------------------------------")
+                    self.coverage.load()
+                    summary = self.coverage.data.summary(fullpath=True)
+                    if summary:
+                        filenames = sorted(summary.keys())
+                        for f in filenames:
+                            print("%s: %d lines" % (f, summary[f]))
+                    else:
+                        print("No data collected")
+                else:
+                    self.help_fn("Don't know what you mean by %r" % info)
+                    return ERR
+            return OK
+
         if 'erase' in options.actions or options.erase_first:
             self.coverage.erase()
         else:
diff --git a/coverage/collector.py b/coverage/collector.py
index a121193d..3b56d241 100644
--- a/coverage/collector.py
+++ b/coverage/collector.py
@@ -118,6 +118,10 @@ class Collector:
             # trace function.
             self._trace_class = Tracer or PyTracer
 
+    def tracer_name(self):
+        """Return the class name of the tracer we're using."""
+        return self._trace_class.__name__
+
     def reset(self):
         """Clear collected data, and prepare to collect more."""
         # A dictionary with an entry for (Python source file name, line number
diff --git a/coverage/control.py b/coverage/control.py
index 4fdec930..d51dd294 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -332,3 +332,27 @@ class coverage:
             outfile = open(outfile, "w")
         reporter = XmlReporter(self, ignore_errors)
         reporter.report(morfs, omit_prefixes=omit_prefixes, outfile=outfile)
+
+    def sysinfo(self):
+        """Return a list of key,value pairs showing internal information."""
+        
+        import coverage as covmod
+        import platform, re, sys
+
+        info = [
+            ('version', covmod.__version__),
+            ('coverage', covmod.__file__),
+            ('cover_prefix', self.cover_prefix),
+            ('pylib_prefix', self.pylib_prefix),
+            ('tracer', self.collector.tracer_name()),
+            ('data_file', self.data.filename),
+            ('python', sys.version),
+            ('platform', platform.platform()),
+            ('cwd', os.getcwd()),
+            ('path', sys.path),
+            ('environment', [
+                ("%s = %s" % (k, v)) for k, v in os.environ.items()
+                    if re.search("^COV|^PY", k)
+                ]),
+            ]
+        return info
diff --git a/coverage/data.py b/coverage/data.py
index 4d368f55..54979658 100644
--- a/coverage/data.py
+++ b/coverage/data.py
@@ -164,14 +164,19 @@ class CoverageData:
         """
         return self.lines.get(filename) or {}
 
-    def summary(self):
+    def summary(self, fullpath=False):
         """Return a dict summarizing the coverage data.
         
-        Keys are the basename of the filenames, and values are the number of
-        executed lines.  This is useful in the unit tests.
+        Keys are based on the filenames, and values are the number of executed
+        lines.  If `fullpath` is true, then the keys are the full pathnames of
+        the files, otherwise they are the basenames of the files.
         
         """
         summ = {}
+        if fullpath:
+            filename_fn = lambda f: f
+        else:
+            filename_fn = os.path.basename
         for filename, lines in self.lines.items():
-            summ[os.path.basename(filename)] = len(lines)
+            summ[filename_fn(filename)] = len(lines)
         return summ
diff --git a/test/test_cmdline.py b/test/test_cmdline.py
index d2413712..7e7cba2a 100644
--- a/test/test_cmdline.py
+++ b/test/test_cmdline.py
@@ -66,18 +66,23 @@ class CmdLineTest(CoverageTest):
         self.assertEqual(m1.method_calls, m2.method_calls)
 
     def cmd_help(self, args, help_msg=None, topic=None, ret=ERR):
-        """Run a command line, and check that it prints the right help."""
+        """Run a command line, and check that it prints the right help.
+        
+        Only the last function call in the mock is checked, which should be the
+        help message that we want to see.
+        
+        """
         m, r = self.mock_command_line(args)
         self.assertEqual(r, ret,
                 "Wrong status: got %s, wanted %s" % (r, ret)
                 )
         if help_msg:
-            self.assertEqual(m.method_calls,
-                [('help_fn', (help_msg,), {})]
+            self.assertEqual(m.method_calls[-1],
+                ('help_fn', (help_msg,), {})
                 )
         else:
-            self.assertEqual(m.method_calls,
-                [('help_fn', (), {'topic':topic})]
+            self.assertEqual(m.method_calls[-1],
+                ('help_fn', (), {'topic':topic})
                 )
             
 
@@ -340,6 +345,16 @@ class NewCmdLineTest(CmdLineTest):
     def testCombine(self):
         self.cmd_executes_same("combine", "-c")
 
+    def testDebug(self):
+        self.cmd_help("debug", "What information would you like: data, sys?")
+        self.cmd_help("debug foo", "Don't know what you mean by 'foo'")
+
+    def testDebugSys(self):
+        self.command_line("debug sys")
+        out = self.stdout()
+        assert "version:" in out
+        assert "data_file:" in out
+    
     def testErase(self):
         self.cmd_executes_same("erase", "-e")