4 files changed, 116 insertions, 0 deletions
diff --git a/tests/modules/plugins/__init__.py b/tests/modules/plugins/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/tests/modules/plugins/__init__.py
diff --git a/tests/modules/plugins/a_plugin.py b/tests/modules/plugins/a_plugin.py
new file mode 100644
index 00000000..93ac4854
--- /dev/null
+++ b/tests/modules/plugins/a_plugin.py
@@ -0,0 +1,6 @@
+"""A plugin for tests to reference."""
+
+from coverage.plugin import CoveragePlugin
+
+class Plugin(CoveragePlugin):
+    pass
diff --git a/tests/modules/plugins/another.py b/tests/modules/plugins/another.py
new file mode 100644
index 00000000..93ac4854
--- /dev/null
+++ b/tests/modules/plugins/another.py
@@ -0,0 +1,6 @@
+"""A plugin for tests to reference."""
+
+from coverage.plugin import CoveragePlugin
+
+class Plugin(CoveragePlugin):
+    pass
diff --git a/tests/test_plugins.py b/tests/test_plugins.py
new file mode 100644
index 00000000..bc94b983
--- /dev/null
+++ b/tests/test_plugins.py
@@ -0,0 +1,104 @@
+"""Tests for plugins."""
+
+import coverage
+from coverage.plugin import load_plugins
+
+from tests.coveragetest import CoverageTest
+
+
+class FakeConfig(object):
+    """A fake config for use in tests."""
+
+    def __init__(self, plugin, options):
+        self.plugin = plugin
+        self.options = options
+        self.asked_for = []
+
+    def get_plugin_options(self, module):
+        """Just return the options for `module` if this is the right module."""
+        self.asked_for.append(module)
+        if module == self.plugin:
+            return self.options
+        else:
+            return {}
+
+
+class PluginUnitTest(CoverageTest):
+    """Test load_plugins directly."""
+
+    def test_importing_and_configuring(self):
+        self.make_file("plugin1.py", """\
+            from coverage.plugin import CoveragePlugin
+
+            class Plugin(CoveragePlugin):
+                def __init__(self, options):
+                    super(Plugin, self).__init__(options)
+                    self.this_is = "me"
+            """)
+
+        config = FakeConfig("plugin1", {'a':'hello'})
+        plugins = load_plugins(["plugin1"], config)
+
+        self.assertEqual(len(plugins), 1)
+        self.assertEqual(plugins[0].this_is, "me")
+        self.assertEqual(plugins[0].options, {'a':'hello'})
+        self.assertEqual(config.asked_for, ['plugin1'])
+
+    def test_importing_and_configuring_more_than_one(self):
+        self.make_file("plugin1.py", """\
+            from coverage.plugin import CoveragePlugin
+
+            class Plugin(CoveragePlugin):
+                def __init__(self, options):
+                    super(Plugin, self).__init__(options)
+                    self.this_is = "me"
+            """)
+        self.make_file("plugin2.py", """\
+            from coverage.plugin import CoveragePlugin
+
+            class Plugin(CoveragePlugin):
+                pass
+            """)
+
+        config = FakeConfig("plugin1", {'a':'hello'})
+        plugins = load_plugins(["plugin1", "plugin2"], config)
+
+        self.assertEqual(len(plugins), 2)
+        self.assertEqual(plugins[0].this_is, "me")
+        self.assertEqual(plugins[0].options, {'a':'hello'})
+        self.assertEqual(plugins[1].options, {})
+        self.assertEqual(config.asked_for, ['plugin1', 'plugin2'])
+
+    def test_cant_import(self):
+        with self.assertRaises(ImportError):
+            _ = load_plugins(["plugin_not_there"], None)
+
+    def test_ok_to_not_define_plugin(self):
+        self.make_file("plugin2.py", """\
+            from coverage.plugin import CoveragePlugin
+
+            Nothing = 0
+            """)
+        plugins = load_plugins(["plugin2"], None)
+        self.assertEqual(plugins, [])
+
+
+class PluginTest(CoverageTest):
+    """Test plugins through the Coverage class."""
+
+    def test_plugin_imported(self):
+        self.make_file("my_plugin.py", """\
+            with open("evidence.out", "w") as f:
+                f.write("we are here!")
+            """)
+
+        self.assert_doesnt_exist("evidence.out")
+        _ = coverage.Coverage(plugins=["my_plugin"])
+
+        with open("evidence.out") as f:
+            self.assertEqual(f.read(), "we are here!")
+
+    def test_bad_plugin_raises_import_error(self):
+        with self.assertRaises(ImportError):
+            cov = coverage.Coverage(plugins=["foo"])
+            cov.start()