Add unittest for metrics_example.py

docs/getting_started/tests/test_metrics.py

@@ -0,0 +1,29 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import os
+import subprocess
+import sys
+import unittest
+
+
+class TestBasicMetricsExample(unittest.TestCase):
+    def test_basic_tracer(self):
+        dirpath = os.path.dirname(os.path.realpath(__file__))
+        test_script = "{}/../metrics_example.py".format(dirpath)
+        output = subprocess.check_output(
+            (sys.executable, test_script)
+        ).decode()
+
+        self.assertIn('name="requests"', output)
+        self.assertIn('description="number of requests"', output)