Add coverage

tools/telemetry/third_party/coverage/tests/farm/run/run_timid.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
+
+# Test that the --timid command line argument properly swaps the tracer
+# function for a simpler one.
+#
+# This is complicated by the fact that the tests are run twice for each
+# version: once with a compiled C-based trace function, and once without
+# it, to also test the Python trace function.  So this test has to examine
+# an environment variable set in igor.py to know whether to expect to see
+# the C trace function or not.
+
+import os
+
+# When meta-coverage testing, this test doesn't work, because it finds
+# coverage.py's own trace function.
+if os.environ.get('COVERAGE_COVERAGE', ''):
+    skip("Can't test timid during coverage measurement.")
+
+copy("src", "out")
+run("""
+    python showtrace.py none
+    coverage run showtrace.py regular
+    coverage run --timid showtrace.py timid
+    """, rundir="out", outfile="showtraceout.txt")
+
+# When running without coverage, no trace function
+# When running timidly, the trace function is always Python.
+contains("out/showtraceout.txt",
+    "none None",
+    "timid PyTracer",
+    )
+
+if os.environ.get('COVERAGE_TEST_TRACER', 'c') == 'c':
+    # If the C trace function is being tested, then regular running should have
+    # the C function, which registers itself as f_trace.
+    contains("out/showtraceout.txt", "regular CTracer")
+else:
+    # If the Python trace function is being tested, then regular running will
+    # also show the Python function.
+    contains("out/showtraceout.txt", "regular PyTracer")
+
+clean("out")