A new kind of plug-in: configurers. #563

2 files changed, 38 insertions, 3 deletions

diff --git a/tests/plugin_config.py b/tests/plugin_config.py
new file mode 100644
index 0000000..67a790a
--- /dev/null
+++ b/tests/plugin_config.py
@@ -0,0 +1,22 @@
+# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+# For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt
+
+"""A configuring plugin for test_plugins.py to import."""
+
+import coverage
+
+
+class Plugin(coverage.CoveragePlugin):
+    """A configuring plugin for testing."""
+    def configure(self, config):
+        """Configure all the things!"""
+        opt_name = "report:exclude_lines"
+        exclude_lines = config.get_option(opt_name)
+        exclude_lines.append(r"pragma: custom")
+        exclude_lines.append(r"pragma: or whatever")
+        config.set_option(opt_name, exclude_lines)
+
+
+def coverage_init(reg, options):        # pylint: disable=unused-argument
+    """Called by coverage to initialize the plugins here."""
+    reg.add_configurer(Plugin())
diff --git a/tests/test_plugins.py b/tests/test_plugins.py
index 4dfe0bd..c4fc3ac 100644
--- a/tests/test_plugins.py
+++ b/tests/test_plugins.py
@@ -621,10 +621,10 @@ class BadFileTracerTest(FileTracerTest):
 
         # There should be a warning explaining what's happening, but only one.
         # The message can be in two forms:
-        #   Disabling plugin '...' due to previous exception
+        #   Disabling plug-in '...' due to previous exception
         # or:
-        #   Disabling plugin '...' due to an exception:
-        msg = "Disabling plugin '%s.%s' due to " % (module_name, plugin_name)
+        #   Disabling plug-in '...' due to an exception:
+        msg = "Disabling plug-in '%s.%s' due to " % (module_name, plugin_name)
         warnings = stderr.count(msg)
         self.assertEqual(warnings, 1)
 
@@ -848,3 +848,16 @@ class BadFileTracerTest(FileTracerTest):
         self.run_bad_plugin(
             "bad_plugin", "Plugin", our_error=False, excmsg="an integer is required",
         )
+
+
+class ConfigurerPluginTest(CoverageTest):
+    """Test configuring plugins."""
+
+    def test_configurer_plugin(self):
+        cov = coverage.Coverage()
+        cov.set_option("run:plugins", ["tests.plugin_config"])
+        cov.start()
+        cov.stop()      # pragma: nested
+        excluded = cov.get_option("report:exclude_lines")
+        self.assertIn("pragma: custom", excluded)
+        self.assertIn("pragma: or whatever", excluded)