s-exp.legba.json-schema — com.s-exp/legba 1.0.0-alpha99

JSON Schema validation utilities. Provides helpers to load, cache, and validate JSON Schemas

schema clj

(schema schema-uri
        &
        {:as _opts
         :keys [schema-validator-config]
         :or {schema-validator-config schema-validator-config}})

Loads and builds a JSON Schema validator instance from a URI or file path.

Arguments:

• schema-uri (string): Location of the JSON Schema (file:/..., http:/..., classpath:/..., etc)

• :schema-validator-config (optional): Custom SchemaValidatorsConfig (default: this namespace's schema-validator-config).

Returns:

An instance of the JSON Schema validator (com.networknt.schema.JsonSchema). This object can be reused to validate multiple values or payloads.

Example: (schema "classpath:///tmp/foo.schema.json") (schema "file:///data/schema/bar.json") (schema "https://schemas.org/example.schema.json")

schema-validator-config clj

Default reusable SchemaValidatorsConfig instance.

This configures the validator to:

• Enable JSON Schema reference preloading and caching
• Enable format assertions (per the JSON Schema spec)
• Set maximum reference nesting depth to 40
• Handle nullable fields correctly
• Use JSON_PATH for error paths in validation results

This config can be reused for schema load/validation for performance and consistency.

validate! clj

(validate! schema
           val
           &
           {:as _opts
            :keys [validation-result]
            :or {validation-result validation-result}})

Validates a value against a previously loaded or constructed schema.

Arguments:

• schema: The schema object returned from schema
• val: The input to validate. Can be a JsonNode or a JSON string.
• :validation-result (optional): Override for the function used to extract validation errors (defaults to this namespace's validation-result).

Returns: A sequence of error maps (see validation-result), or nil if valid.

Example: (validate! myschema "{"foo":42}") (validate! myschema my-jackson-json-node)

validation-result clj

(validation-result r)

Extracts validation errors from a ValidationResult object.

Arguments:

• r (ValidationResult): The result object returned by a validation call.

Returns: A sequence of maps, one for each validation error, containing:

• :type: Error type string from validation
• :path: JSON path to offending element
• :error: Error code string
• :message: Human-friendly error message Returns nil if the validation result contains no errors.