Merge pull request #901 from jd/fix-opentracer-start-custom-time

[opentracer] Fix flaky test based on sleep

Author: jd

tests/opentracer/test_tracer.py

@@ -16,6 +16,7 @@
 from ddtrace.propagation.http import HTTP_HEADER_TRACE_ID
 from ddtrace.settings import ConfigException
 
+import mock
 import pytest
 
 
@@ -125,13 +126,14 @@ def test_start_span_references(self, ot_tracer, writer):
 
     def test_start_span_custom_start_time(self, ot_tracer):
         """Start a span with a custom start time."""
-        t = time.time() + 0.002
-        with ot_tracer.start_span('myop', start_time=t) as span:
-            time.sleep(0.005)
+        t = 100
+        with mock.patch('time.time') as time:
+            time.return_value = 102
+            with ot_tracer.start_span('myop', start_time=t) as span:
+                pass
 
-        # it should be certain that the span duration is strictly less than
-        # the amount of time we sleep for
-        assert span._dd_span.duration < 0.005
+        assert span._dd_span.start == t
+        assert span._dd_span.duration == 2
 
     def test_start_span_with_spancontext(self, ot_tracer, writer):
         """Start and finish a span using a span context as the child_of