github.com/santhosh-tekuri/jsonschema

jsonschema

Package jsonschema provides json-schema compilation and validation.

This implementation of JSON Schema, supports draft4, draft6 and draft7.

Passes all tests(including optional) in https://github.com/json-schema/JSON-Schema-Test-Suite

An example of using this package:

schema, err := jsonschema.Compile("schemas/purchaseOrder.json")
if err != nil {
    return err
}
f, err := os.Open("purchaseOrder.json")
if err != nil {
    return err
}
defer f.Close()
if err = schema.Validate(f); err != nil {
    return err
}

The schema is compiled against the version specified in $schema property. If $schema property is missing, it uses latest draft which currently is draft7. You can force to use draft4 when $schema is missing, as follows:

compiler := jsonschema.NewCompiler()
compler.Draft = jsonschema.Draft4

you can also validate go value using schema.ValidateInterface(interface{}) method.
but the argument should not be user-defined struct.

This package supports loading json-schema from filePath and fileURL.

To load json-schema from HTTPURL, add following import:

import _ "github.com/santhosh-tekuri/jsonschema/httploader"

Loading from urls for other schemes (such as ftp), can be plugged in. see package jsonschema/httploader for an example

To load json-schema from in-memory:

data := `{"type": "string"}`
url := "sch.json"
compiler := jsonschema.NewCompiler()
if err := compiler.AddResource(url, strings.NewReader(data)); err != nil {
    return err
}
schema, err := compiler.Compile(url)
if err != nil {
    return err
}
f, err := os.Open("doc.json")
if err != nil {
    return err
}
defer f.Close()
if err = schema.Validate(f); err != nil {
    return err
}

This package supports json string formats:

• date-time
• date
• time
• hostname
• email
• ip-address
• ipv4
• ipv6
• uri
• uriref/uri-reference
• regex
• format
• json-pointer
• relative-json-pointer
• uri-template (limited validation)

Developers can register their own formats using package "github.com/santhosh-tekuri/jsonschema/formats".

"base64" contentEncoding is supported. Custom decoders can be registered using package "github.com/santhosh-tekuri/jsonschema/decoders".

"application/json" contentMediaType is supported. Custom mediatypes can be registered using package "github.com/santhosh-tekuri/jsonschema/mediatypes".

ValidationError

The ValidationError returned by Validate method contains detailed context to understand why and where the error is.

schema.json:

{
      "$ref": "t.json#/definitions/employee"
}

t.json:

{
    "definitions": {
        "employee": {
            "type": "string"
        }
    }
}

doc.json:

1

Validating doc.json with schema.json, gives following ValidationError:

I[#] S[#] doesn't validate with "schema.json#"
  I[#] S[#/$ref] doesn't valide with "t.json#/definitions/employee"
    I[#] S[#/definitions/employee/type] expected string, but got number

Here I stands for instance document and S stands for schema document.
The json-fragments that caused error in instance and schema documents are represented using json-pointer notation.
Nested causes are printed with indent.

CLI

jv <schema-file> [<json-doc>]...

if no <json-doc> arguments are passed, it simply validates the <schema-file>.

exit-code is 1, if there are any validation errors