Add coverage

tools/telemetry/third_party/coverage/tests/goldtest.py

+# 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 test base class for tests based on gold file comparison."""
+
+import os
+import sys
+
+from tests.coveragetest import CoverageTest
+
+from coverage.test_helpers import change_dir    # pylint: disable=unused-import
+from tests.test_farm import clean
+# Import helpers, eventually test_farm.py will go away.
+from tests.test_farm import (       # pylint: disable=unused-import
+    compare, contains, doesnt_contain, contains_any,
+)
+
+
+class CoverageGoldTest(CoverageTest):
+    """A test based on gold files."""
+
+    run_in_temp_dir = False
+
+    def setUp(self):
+        super(CoverageGoldTest, self).setUp()
+        self.chdir(self.root_dir)
+        # Modules should be importable from the current directory.
+        sys.path.insert(0, '')
+
+    def output_dir(self, the_dir):
+        """Declare where the output directory is.
+
+        The output directory is deleted at the end of the test, unless the
+        COVERAGE_KEEP_OUTPUT environment variable is set.
+
+        """
+        self.addCleanup(self.cleanup_output_dir, the_dir)
+
+    def cleanup_output_dir(self, the_dir):
+        """Clean up the output directory of the test."""
+        if not os.environ.get("COVERAGE_KEEP_OUTPUT"):      # pragma: partial
+            clean(the_dir)