Merge pull request #133 from prometheus/parse-comma

Support trailing commas in parser

Author: brian-brazil

prometheus_client/parser.py

@@ -71,7 +71,7 @@ def _parse_sample(text):
                 value.append(char)
                 state = 'value'
         elif state == 'startoflabelname':
-            if char == ' ' or char == '\t':
+            if char == ' ' or char == '\t' or char == ',':
                 pass
             elif char == '}':
                 state = 'endoflabels'
@@ -121,7 +121,7 @@ def _parse_sample(text):
                 labelvalue.append('\\' + char)
         elif state == 'nextlabel':
             if char == ',':
-                state = 'labelname'
+                state = 'startoflabelname'
             elif char == '}':
                 state = 'endoflabels'
             elif char == ' ' or char == '\t':

tests/test_parser.py

@@ -135,6 +135,26 @@ def test_spaces(self):
         metric_family.add_metric(["baz"], 2)
         self.assertEqual([metric_family], list(families))
 
+    def test_commas(self):
+        families = text_string_to_metric_families("""# TYPE a counter
+# HELP a help
+a{foo="bar",} 1
+# TYPE b counter
+# HELP b help
+b{,} 2
+""")
+        a = CounterMetricFamily("a", "help", labels=["foo"])
+        a.add_metric(["bar"], 1)
+        b = CounterMetricFamily("b", "help", value=2)
+        self.assertEqual([a, b], list(families))
+
+    def test_empty_brackets(self):
+        families = text_string_to_metric_families("""# TYPE a counter
+# HELP a help
+a{} 1
+""")
+        self.assertEqual([CounterMetricFamily("a", "help", value=1)], list(families))
+
     def test_nan(self):
         families = text_string_to_metric_families("""a NaN
 """)