Cleaning up name before appending unit on name

Signed-off-by: Amim Knabben <amim.knabben@gmail.com>

prometheus_client/metrics.py

@@ -27,12 +27,12 @@ def _build_full_name(metric_type, name, namespace, subsystem, unit):
     if subsystem:
         full_name += subsystem + '_'
     full_name += name
+    if metric_type == 'counter' and full_name.endswith('_total'):
+        full_name = full_name[:-6]  # Munge to OpenMetrics.
     if unit and not full_name.endswith("_" + unit):
         full_name += "_" + unit
     if unit and metric_type in ('info', 'stateset'):
         raise ValueError('Metric name is of a type that cannot have a unit: ' + full_name)
-    if metric_type == 'counter' and full_name.endswith('_total'):
-        full_name = full_name[:-6]  # Munge to OpenMetrics.
     return full_name
 
 

tests/test_asgi.py

@@ -121,3 +121,20 @@ def test_report_metrics_3(self):
 
     def test_report_metrics_4(self):
         self.validate_metrics("failed_requests", "Number of failed requests", 7)
+
+    def test_report_metrics_with_unit_append(self):
+        help_text = "Requests counter"
+        increments = 6
+
+        c = Counter("requests", help_text, unit="total", registry=self.registry)
+        c.inc(increments)
+
+        app = make_asgi_app(self.registry)
+        self.seed_app(app)
+        self.send_default_request()
+        outputs = self.get_all_output()
+        output = outputs[1]['body'].decode('utf8')
+
+        self.assertIn("# HELP requests_total_total {0}".format(help_text), output)
+        self.assertIn("# TYPE requests_total_total counter\n", output)
+        self.assertIn("requests_total_total " + str(increments) + ".0\n", output)

tests/test_core.py

@@ -527,6 +527,11 @@ def test_no_units_for_info_enum(self):
         self.assertRaises(ValueError, Info, 'foo', 'help', unit="x")
         self.assertRaises(ValueError, Enum, 'foo', 'help', unit="x")
 
+    def test_name_cleanup_before_unit_append(self):
+        self.assertEqual(self.counter._name, 'c')
+        self.c = Counter('c_total', 'help', unit="total", labelnames=['l'], registry=self.registry)
+        self.assertEqual(self.c._name, 'c_total')
+
 
 class TestMetricFamilies(unittest.TestCase):
     def setUp(self):

tests/test_wsgi.py

@@ -67,3 +67,18 @@ def test_report_metrics_3(self):
 
     def test_report_metrics_4(self):
         self.validate_metrics("failed_requests", "Number of failed requests", 7)
+
+    def test_report_metrics_with_unit_append(self):
+        help_text = "Requests counter"
+        increments = 6
+
+        c = Counter("requests", help_text, unit="total", registry=self.registry)
+        c.inc(increments)
+
+        app = make_wsgi_app(self.registry)
+        outputs = app(self.environ, self.capture)
+        output = outputs[0].decode('utf8')
+
+        self.assertIn("# HELP requests_total_total {0}".format(help_text), output)
+        self.assertIn("# TYPE requests_total_total counter\n", output)
+        self.assertIn("requests_total_total " + str(increments) + ".0\n", output)