Indication of position(line and column) in json-file, when the validation against json-schema fails

[Omar-Medina]

Hello dear json-schema-validator-team,
Is it possible to get the position (line and column) in a JSON file when validation against a JSON schema fails?

This can help pinpoint exactly where the error occurs, making it easier to troubleshoot and fix the input file.

I use the following versions:

nLohman version 3.11.3
json-schema-validator : 2.3.0

Due to the following reasons:

• "name" is defined in schema as type "string"
• The key property "cas" is not defined in the schemaFor the following json object.

the json-schema-validator-library reports for the json input

{"elm":[{"str":{"name":3}},{"str":{"cas":"z"}}]}

the next error message:

Error: /elm/0/str/name, Instance=3, message=unexpected instance type
Error: /elm/1/str, Instance={"cas":"z"}, message=validation failed for additional property 'cas': instance invalid as per false-schema

The indication of line and column will be helpfull for fixing the JSON-file .

By the way. the error reported by son-schema-validator-library is "for me" more understanble compared to other library for the same error (In this case were only 2 errors):

Validation failed:
Error: 1
Content:<root>[elm][0][str][name]
description:Value type not permitted by 'type' constraint.
Error: 2
Content:<root>[elm][0][str]
description:Failed to validate against schema associated with property name 'name'.
Error: 3
Content:<root>[elm][0]
description:Failed to validate against schema associated with property name 'str'.
Error: 4
Content:<root>[elm]
description:Failed to validate item #0 in array.
Error: 5
Content:<root>[elm][1][str]
description:Object contains a property that could not be validated using 'properties' or 'additionalProperties' constraints: 'cas'.
Error: 6
Content:<root>[elm][1]
description:Failed to validate against schema associated with property name 'str'.
Error: 7
Content:<root>[elm]
description:Failed to validate item #1 in array.
Error: 8
Content:<root>
description:Failed to validate against schema associated with property name 'elm'.

It will be great , that this information (position) is provided.

OR,

You can provide me information (code / function) how to extend/modify the code to get the possition.
I am aware, that the nLohmann library provides the position principle/usually in detected exceptions.
See: nlohmann/json#4649

By the way. Last but not least and Just for your information (I can try to fix that, if you provide a little information, where to start).
If the define JSON_DIAGNOSTICS is enabled ans set to 1, then the c++ linker reports the following message:
I use the TDM-GCC-64 compiler in windows environment

TDM-GCC-64/bin/../lib/gcc/x86_64-w64-mingw32/10.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: Core\ELM\COMMON\JsonHandler\JsonHandler.o:JsonHandler.cpp:(.text+0x483d): undefined reference to `nlohmann::json_schema::json_validator::set_root_schema(nlohmann::json_abi_diag_v3_11_3::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long long, unsigned long long, double, std::allocator, nlohmann::json_abi_diag_v3_11_3::adl_serializer, std::vector<unsigned char, std::allocator<unsigned char> >, void> const&)'
TDM-GCC-64/bin/../lib/gcc/x86_64-w64-mingw32/10.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: Core\ELM\COMMON\JsonHandler\JsonHandler.o:JsonHandler.cpp:(.text+0x4984): undefined reference to `nlohmann::json_schema::json_validator::validate(nlohmann::json_abi_diag_v3_11_3::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long long, unsigned long long, double, std::allocator, nlohmann::json_abi_diag_v3_11_3::adl_serializer, std::vector<unsigned char, std::allocator<unsigned char> >, void> const&, nlohmann::json_schema::error_handler&, nlohmann::json_uri const&) const'

undefined reference to `nlohmann::json_schema::json_validator::set_root_schema
undefined reference to `nlohmann::json_schema::json_validator::validate

Also When the define JSON_DIAGNOSTICS is not enabled ( set to 0 ), then the c++ linker does not report any error.

Your library has been incredibly helpful, and I appreciate the hard work you put into it.

Omar

[pboettch]

With the latest version of nlohmann::json I don't know, but with versions I used heavily the file location information is lost after the json-file has been parsed. In other words, once you have your json-variable available the file location origin of this key cannot be retrieved any longer.

Therefore the validator is unable to provide the file location if it encounters a validation failure.

Maybe you could ask at nlohmann/json whether file locations can be retrieved after parsing.