openmetrics: Throw error on blank line (prometheus#576)

mrueg · web-flow · commit 3627472bd325 · 2020-09-04T23:40:15.000+01:00
As per current spec draft blank lines are not allowed

Signed-off-by: Manuel Rüger &lt;manuel@rueg.eu&gt;
diff --git a/prometheus_client/openmetrics/parser.py b/prometheus_client/openmetrics/parser.py
@@ -482,6 +482,9 @@ def build_metric(name, documentation, typ, unit, samples):
         if eof:
             raise ValueError("Received line after # EOF: " + line)
 
+        if not line:
+            raise ValueError("Received blank line")
+
         if line == '# EOF':
             eof = True
         elif line.startswith('#'):
diff --git a/tests/openmetrics/test_parser.py b/tests/openmetrics/test_parser.py
@@ -598,6 +598,8 @@ def test_invalid_input(self):
         for case in [
             # No EOF.
             (''),
+            # Blank line
+            ('a 1\n\n# EOF\n'),
             # Text after EOF.
             ('a 1\n# EOF\nblah'),
             ('a 1\n# EOFblah'),
