Optionally skip empty files in reports

11 files changed, 110 insertions, 5 deletions

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index 66d4dc3c..ef1184d0 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -93,6 +93,10 @@ class Opts(object):
         '--skip-covered', action='store_true',
         help="Skip files with 100% coverage.",
     )
+    skip_empty = optparse.make_option(
+        '--skip-empty', action='store_true',
+        help="Skip empty files.",
+    )
     show_contexts = optparse.make_option(
         '--show-contexts', action='store_true',
         help="Show contexts for covered lines.",
@@ -203,6 +207,7 @@ class CoverageOptionParser(optparse.OptionParser, object):
             rcfile=True,
             show_missing=None,
             skip_covered=None,
+            skip_empty=None,
             show_contexts=None,
             source=None,
             timid=None,
@@ -354,6 +359,7 @@ CMDS = {
             Opts.omit,
             Opts.title,
             Opts.skip_covered,
+            Opts.skip_empty,
             Opts.show_contexts,
             Opts.contexts,
             ] + GLOBAL_ARGS,
@@ -375,6 +381,7 @@ CMDS = {
             Opts.contexts,
             Opts.show_missing,
             Opts.skip_covered,
+            Opts.skip_empty,
             ] + GLOBAL_ARGS,
         usage="[options] [modules]",
         description="Report coverage statistics on modules."
@@ -575,6 +582,7 @@ class CoverageScript(object):
             total = self.coverage.report(
                 show_missing=options.show_missing,
                 skip_covered=options.skip_covered,
+                skip_empty=options.skip_empty,
                 **report_args
                 )
         elif options.action == "annotate":
@@ -584,6 +592,7 @@ class CoverageScript(object):
                 directory=options.directory,
                 title=options.title,
                 skip_covered=options.skip_covered,
+                skip_empty=options.skip_empty,
                 show_contexts=options.show_contexts,
                 **report_args
                 )
diff --git a/coverage/config.py b/coverage/config.py
index 7d691145..c6689d2d 100644
--- a/coverage/config.py
+++ b/coverage/config.py
@@ -205,6 +205,7 @@ class CoverageConfig(object):
         self.report_contexts = None
         self.show_missing = False
         self.skip_covered = False
+        self.skip_empty = False
 
         # Defaults for [html]
         self.extra_css = None
@@ -362,6 +363,7 @@ class CoverageConfig(object):
         ('report_omit', 'report:omit', 'list'),
         ('show_missing', 'report:show_missing', 'boolean'),
         ('skip_covered', 'report:skip_covered', 'boolean'),
+        ('skip_empty', 'report:skip_empty', 'boolean'),
         ('sort', 'report:sort'),
 
         # [html]
diff --git a/coverage/control.py b/coverage/control.py
index 7be28413..ff015882 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -774,7 +774,7 @@ class Coverage(object):
     def report(
         self, morfs=None, show_missing=None, ignore_errors=None,
         file=None, omit=None, include=None, skip_covered=None,
-        contexts=None,
+        contexts=None, skip_empty=None,
     ):
         """Write a textual summary report to `file`.
 
@@ -794,6 +794,9 @@ class Coverage(object):
 
         If `skip_covered` is true, don't report on files with 100% coverage.
 
+        If `skip_empty` is true, don't report on empty files (those that have
+        no statements).
+
         `contexts` is a list of regular expressions.  Only data from
         :ref:`dynamic contexts <dynamic_contexts>` that match one of those
         expressions (using :func:`re.search <python:re.search>`) will be
@@ -815,7 +818,7 @@ class Coverage(object):
             self,
             ignore_errors=ignore_errors, report_omit=omit, report_include=include,
             show_missing=show_missing, skip_covered=skip_covered,
-            report_contexts=contexts,
+            report_contexts=contexts, skip_empty=skip_empty,
         ):
             reporter = SummaryReporter(self)
             return reporter.report(morfs, outfile=file)
@@ -843,7 +846,8 @@ class Coverage(object):
 
     def html_report(self, morfs=None, directory=None, ignore_errors=None,
                     omit=None, include=None, extra_css=None, title=None,
-                    skip_covered=None, show_contexts=None, contexts=None):
+                    skip_covered=None, show_contexts=None, contexts=None,
+                    skip_empty=None):
         """Generate an HTML report.
 
         The HTML is written to `directory`.  The file "index.html" is the
@@ -871,6 +875,7 @@ class Coverage(object):
             ignore_errors=ignore_errors, report_omit=omit, report_include=include,
             html_dir=directory, extra_css=extra_css, html_title=title,
             skip_covered=skip_covered, show_contexts=show_contexts, report_contexts=contexts,
+            skip_empty=skip_empty,
         ):
             reporter = HtmlReporter(self)
             return reporter.report(morfs)
diff --git a/coverage/html.py b/coverage/html.py
index 4a0e1a33..e3b814c5 100644
--- a/coverage/html.py
+++ b/coverage/html.py
@@ -282,6 +282,12 @@ class HtmlReporter(object):
                 file_be_gone(html_path)
                 return
 
+        if self.config.skip_empty:
+            # Don't report on empty files.
+            if nums.n_statements == 0:
+                file_be_gone(html_path)
+                return
+
         # Find out if the file on disk is already correct.
         if self.incr.can_skip_file(self.data, fr, rootname):
             self.file_summaries.append(self.incr.index_info(rootname))
diff --git a/coverage/summary.py b/coverage/summary.py
index 08c8a947..97d9fff0 100644
--- a/coverage/summary.py
+++ b/coverage/summary.py
@@ -21,6 +21,7 @@ class SummaryReporter(object):
         self.outfile = None
         self.fr_analysis = []
         self.skipped_count = 0
+        self.empty_count = 0
         self.total = Numbers()
         self.fmt_err = u"%s   %s: %s"
 
@@ -48,6 +49,7 @@ class SummaryReporter(object):
         max_name = max([len(fr.relative_filename()) for (fr, analysis) in self.fr_analysis] + [5])
         fmt_name = u"%%- %ds  " % max_name
         fmt_skip_covered = u"\n%s file%s skipped due to complete coverage."
+        fmt_skip_empty = u"\n%s empty file%s skipped."
 
         header = (fmt_name % "Name") + u" Stmts   Miss"
         fmt_coverage = fmt_name + u"%6d %6d"
@@ -129,6 +131,10 @@ class SummaryReporter(object):
             self.writeout(
                 fmt_skip_covered % (self.skipped_count, 's' if self.skipped_count > 1 else '')
                 )
+        if self.config.skip_empty and self.empty_count:
+            self.writeout(
+                fmt_skip_empty % (self.empty_count, 's' if self.empty_count > 1 else '')
+                )
 
         return self.total.n_statements and self.total.pc_covered
 
@@ -142,5 +148,8 @@ class SummaryReporter(object):
         if self.config.skip_covered and no_missing_lines and no_missing_branches:
             # Don't report on 100% files.
             self.skipped_count += 1
+        elif self.config.skip_empty and nums.n_statements == 0:
+            # Don't report on empty files.
+            self.empty_count += 1
         else:
             self.fr_analysis.append((fr, analysis))
diff --git a/doc/config.rst b/doc/config.rst
index e332f50a..d7623532 100644
--- a/doc/config.rst
+++ b/doc/config.rst
@@ -294,6 +294,11 @@ missing lines.  See :ref:`cmd_summary` for more information.
 ``skip_covered`` (boolean, default False): Don't include files in the report
 that are 100% covered files. See :ref:`cmd_summary` for more information.
 
+.. _config_report_skip_empty:
+
+``skip_empty`` (boolean, default False): Don't include empty files (those that
+have 0 statements) in the report. See :ref:`cmd_summary` for more information.
+
 .. _config_report_sort:
 
 ``sort`` (string, default "Name"): Sort the text report by the named column.
diff --git a/tests/test_api.py b/tests/test_api.py
index b2143548..6455d097 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -904,7 +904,8 @@ class TestRunnerPluginTest(CoverageTest):
         cov.combine()
         cov.save()
         report = StringIO()
-        cov.report(show_missing=None, ignore_errors=True, file=report, skip_covered=None)
+        cov.report(show_missing=None, ignore_errors=True, file=report, skip_covered=None,
+                   skip_empty=None)
         self.assertEqual(report.getvalue(), textwrap.dedent("""\
             Name      Stmts   Miss  Cover
             -----------------------------
diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
index 26624b19..666327c8 100644
--- a/tests/test_cmdline.py
+++ b/tests/test_cmdline.py
@@ -37,10 +37,11 @@ class BaseCmdLineTest(CoverageTest):
     _defaults.Coverage().html_report(
         directory=None, ignore_errors=None, include=None, omit=None, morfs=[],
         skip_covered=None, show_contexts=None, title=None, contexts=None,
+        skip_empty=None,
     )
     _defaults.Coverage().report(
         ignore_errors=None, include=None, omit=None, morfs=[],
-        show_missing=None, skip_covered=None, contexts=None,
+        show_missing=None, skip_covered=None, contexts=None, skip_empty=None,
     )
     _defaults.Coverage().xml_report(
         ignore_errors=None, include=None, omit=None, morfs=[], outfile=None,
@@ -261,6 +262,7 @@ class CmdLineTest(BaseCmdLineTest):
         out = self.stdout()
         self.assertIn("cover_pylib:", out)
         self.assertIn("skip_covered:", out)
+        self.assertIn("skip_empty:", out)
 
     def test_erase(self):
         # coverage erase
@@ -370,6 +372,11 @@ class CmdLineTest(BaseCmdLineTest):
             cov.load()
             cov.report(skip_covered=True)
             """)
+        self.cmd_executes("report --skip-empty", """\
+            cov = Coverage()
+            cov.load()
+            cov.report(skip_empty=True)
+            """)
         self.cmd_executes("report --contexts=foo,bar", """\
             cov = Coverage()
             cov.load()
diff --git a/tests/test_config.py b/tests/test_config.py
index ebea18a7..fcbac816 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -311,6 +311,7 @@ class ConfigFileTest(UsingModulesMixin, CoverageTest):
 
         show_missing= TruE
         skip_covered = TruE
+        skip_empty  =TruE
 
         [{section}html]
 
@@ -386,6 +387,7 @@ class ConfigFileTest(UsingModulesMixin, CoverageTest):
         self.assertEqual(cov.config.plugins, ["plugins.a_plugin", "plugins.another"])
         self.assertTrue(cov.config.show_missing)
         self.assertTrue(cov.config.skip_covered)
+        self.assertTrue(cov.config.skip_empty)
         self.assertEqual(cov.config.html_dir, r"c:\tricky\dir.somewhere")
         self.assertEqual(cov.config.extra_css, "something/extra.css")
         self.assertEqual(cov.config.html_title, "Title & nums # nums!")
diff --git a/tests/test_html.py b/tests/test_html.py
index 77e068d0..74cc15d9 100644
--- a/tests/test_html.py
+++ b/tests/test_html.py
@@ -533,6 +533,20 @@ class HtmlTest(HtmlTestHelpers, CoverageTest):
         self.assert_doesnt_exist("htmlcov/main_file_py.html")
         self.assert_exists("htmlcov/not_covered_py.html")
 
+    def test_report_skip_empty_files(self):
+        self.make_file("submodule/__init__.py", "")
+        self.make_file("main_file.py", """
+            import submodule
+
+            def normal():
+                print("z")
+            normal()
+        """)
+        self.run_coverage(htmlargs=dict(skip_empty=True))
+        self.assert_exists("htmlcov/index.html")
+        self.assert_exists("htmlcov/main_file_py.html")
+        self.assert_doesnt_exist("htmlcov/submodule___init___py.html")
+
 
 class HtmlStaticFileTest(CoverageTest):
     """Tests of the static file copying for the HTML report."""
diff --git a/tests/test_summary.py b/tests/test_summary.py
index b25c7764..01b6f9d0 100644
--- a/tests/test_summary.py
+++ b/tests/test_summary.py
@@ -431,6 +431,51 @@ class SummaryTest(UsingModulesMixin, CoverageTest):
         squeezed = self.squeezed_lines(report)
         self.assertEqual(squeezed[0], "No data to report.")
 
+    def test_report_skip_empty(self):
+        self.make_file("main.py", """
+            import submodule
+
+            def normal():
+                print("z")
+            normal()
+            """)
+        self.make_file("submodule/__init__.py", "")
+        self.omit_site_packages()
+        out = self.run_command("coverage run main.py")
+        self.assertEqual(out, "z\n")
+        report = self.report_from_command("coverage report --skip-empty")
+
+        # Name             Stmts   Miss  Cover
+        # ------------------------------------
+        # main.py              4      0   100%
+        # ------------------------------------
+        # TOTAL                4      0   100%
+        #
+        # 1 empty file skipped.
+
+        self.assertEqual(self.line_count(report), 7, report)
+        squeezed = self.squeezed_lines(report)
+        self.assertEqual(squeezed[2], "main.py 4 0 100%")
+        self.assertEqual(squeezed[4], "TOTAL 4 0 100%")
+        self.assertEqual(squeezed[6], "1 empty file skipped.")
+        self.assertEqual(self.last_command_status, 0)
+
+    def test_report_skip_empty_no_data(self):
+        self.make_file("__init__.py", "")
+        self.omit_site_packages()
+        out = self.run_command("coverage run __init__.py")
+        self.assertEqual(out, "")
+        report = self.report_from_command("coverage report --skip-empty")
+
+        # Name             Stmts   Miss  Cover
+        # ------------------------------------
+        #
+        # 1 empty file skipped.
+
+        self.assertEqual(self.line_count(report), 4, report)
+        lines = self.report_lines(report)
+        self.assertEqual(lines[3], "1 empty file skipped.")
+
     def test_report_precision(self):
         self.make_file(".coveragerc", """\
             [report]