Support Jsonnet as a config format

pyrallis/options.py

@@ -1,12 +1,13 @@
 import contextlib
 from typing import Union
 
-from pyrallis.parsers.config_parsers import ParserEnum, YAMLParser, JSONParser, TOMLParser
+from pyrallis.parsers.config_parsers import ParserEnum, YAMLParser, JSONParser, JSONNETParser, TOMLParser
 
 
 class ConfigType(ParserEnum):
     YAML = YAMLParser
     JSON = JSONParser
+    JSONNET = JSONNETParser
     TOML = TOMLParser
 
 

pyrallis/parsers/config_parsers.py

@@ -69,6 +69,24 @@ def save_config(d, stream=None, **kwargs):
             return json.dump(d, stream, **kwargs)
 
 
+class JSONNETParser(JSONParser):
+
+    @staticmethod
+    def parse_string(s):
+        import json
+        import _jsonnet
+        try:
+            s = _jsonnet.evaluate_snippet("snippet", s)  # "snippet" is a dummy filename parameter
+            return json.loads(s)
+        except json.decoder.JSONDecodeError:
+            return s  # No parsing to be done, simply return value
+
+    @staticmethod
+    def load_config(stream):
+        s = stream.read()  # Jsonnet doesn't provide stream API
+        return JSONNETParser.parse_string(s)
+
+
 class TOMLParser(Parser):
 
     @staticmethod

tests/test_decoding.py

@@ -30,7 +30,7 @@ class SomeClass:
     assert pyrallis.decode(SomeClass, pyrallis.encode(b)) == b
 
 
-@parametrize('config_type', ['', 'yaml', 'json', 'toml'])
+@parametrize('config_type', ['', 'yaml', 'json', 'jsonnet', 'toml'])
 def test_dump_load(simple_attribute, config_type, tmp_path):
     some_type, _, expected_value = simple_attribute