Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/nbformat/json_compat.py: 49%

1""" 

2Common validator wrapper to provide a uniform usage of other schema validation 

3libraries. 

4""" 

5 

6# Copyright (c) Jupyter Development Team. 

7# Distributed under the terms of the Modified BSD License. 

8from __future__ import annotations 

9 

10import os 

11 

12import fastjsonschema 

13import jsonschema 

14from fastjsonschema import JsonSchemaException as _JsonSchemaException 

15from jsonschema import Draft4Validator as _JsonSchemaValidator 

16from jsonschema.exceptions import ErrorTree, ValidationError 

17 

18__all__ = [ 

19 "ValidationError", 

20 "JsonSchemaValidator", 

21 "FastJsonSchemaValidator", 

22 "get_current_validator", 

23 "VALIDATORS", 

24] 

25 

26 

27class JsonSchemaValidator: 

28 """A json schema validator.""" 

29 

30 name = "jsonschema" 

31 

32 def __init__(self, schema): 

33 """Initialize the validator.""" 

34 self._schema = schema 

35 self._default_validator = _JsonSchemaValidator(schema) # Default 

36 self._validator = self._default_validator 

37 

38 def validate(self, data): 

39 """Validate incoming data.""" 

40 self._default_validator.validate(data) 

41 

42 def iter_errors(self, data, schema=None): 

43 """Iterate over errors in incoming data.""" 

44 if schema is None: 

45 return self._default_validator.iter_errors(data) 

46 if hasattr(self._default_validator, "evolve"): 

47 return self._default_validator.evolve(schema=schema).iter_errors(data) 

48 return self._default_validator.iter_errors(data, schema) 

49 

50 def error_tree(self, errors): 

51 """Create an error tree for the errors.""" 

52 return ErrorTree(errors=errors) 

53 

54 

55class FastJsonSchemaValidator(JsonSchemaValidator): 

56 """A schema validator using fastjsonschema.""" 

57 

58 name = "fastjsonschema" 

59 

60 def __init__(self, schema): 

61 """Initialize the validator.""" 

62 super().__init__(schema) 

63 self._validator = fastjsonschema.compile(schema) 

64 

65 def validate(self, data): 

66 """Validate incoming data.""" 

67 try: 

68 self._validator(data) 

69 except _JsonSchemaException as error: 

70 raise ValidationError(str(error), schema_path=error.path) from error 

71 

72 def iter_errors(self, data, schema=None): 

73 """Iterate over errors in incoming data.""" 

74 if schema is not None: 

75 return super().iter_errors(data, schema) 

76 

77 errors = [] 

78 validate_func = self._validator 

79 try: 

80 validate_func(data) 

81 except _JsonSchemaException as error: 

82 errors = [ValidationError(str(error), schema_path=error.path)] 

83 

84 return errors 

85 

86 def error_tree(self, errors): 

87 """Create an error tree for the errors.""" 

88 # fastjsonschema's exceptions don't contain the same information that the jsonschema ValidationErrors 

89 # do. This method is primarily used for introspecting metadata schema failures so that we can strip 

90 # them if asked to do so in `nbformat.validate`. 

91 # Another way forward for compatibility: we could distill both validator errors into a custom collection 

92 # for this data. Since implementation details of ValidationError is used elsewhere, we would probably 

93 # just use this data for schema introspection. 

94 msg = "JSON schema error introspection not enabled for fastjsonschema" 

95 raise NotImplementedError(msg) 

96 

97 

98_VALIDATOR_MAP = [ 

99 ("fastjsonschema", fastjsonschema, FastJsonSchemaValidator), 

100 ("jsonschema", jsonschema, JsonSchemaValidator), 

101] 

102VALIDATORS = [item[0] for item in _VALIDATOR_MAP] 

103 

104 

105def _validator_for_name(validator_name): 

106 if validator_name not in VALIDATORS: 

107 msg = f"Invalid validator '{validator_name}' value!\nValid values are: {VALIDATORS}" 

108 raise ValueError(msg) 

109 

110 for name, module, validator_cls in _VALIDATOR_MAP: 

111 if module and validator_name == name: 

112 return validator_cls 

113 # we always return something. 

114 msg = f"Missing validator for {validator_name!r}" 

115 raise ValueError(msg) 

116 

117 

118def get_current_validator(): 

119 """ 

120 Return the default validator based on the value of an environment variable. 

121 """ 

122 validator_name = os.environ.get("NBFORMAT_VALIDATOR", "fastjsonschema") 

123 return _validator_for_name(validator_name)