is-my-json-valid
A JSONSchema validator that uses code generation to be extremely fast
npm install is-my-json-valid
It passes the entire JSONSchema v4 test suite except for remoteRefs and maxLength/minLength when using unicode surrogate pairs.
Usage
Simply pass a schema to compile it
var validator = require('is-my-json-valid')
var validate = validator({
required: true,
type: 'object',
properties: {
hello: {
required: true,
type: 'string'
}
}
})
console.log('should be valid', validate({hello: 'world'}))
console.log('should not be valid', validate({}))
// get the last list of errors by checking validate.errors
// the following will print [{field: 'data.hello', message: 'is required'}]
console.log(validate.errors)You can also pass the schema as a string
var validate = validate('{"type": ... }')Optionally you can use the require submodule to load a schema from __dirname
var validator = require('is-my-json-valid/require')
var validate = validator('my-schema.json')Custom formats
is-my-json-valid supports the formats specified in JSON schema v4 (such as date-time). If you want to add your own custom formats pass them as the formats options to the validator
var validate = validator({
type: 'string',
required: true,
format: 'only-a'
}, {
formats: {
'only-a': /^a+$/
}
})
console.log(validate('aa')) // true
console.log(validate('ab')) // falseExternal schemas
You can pass in external schemas that you reference using the $ref attribute as the schemas option
var ext = {
required: true,
type: 'string'
}
var schema = {
$ref: '#ext' // references another schema called ext
}
// pass the external schemas as an option
var validate = validate(schema, {schemas: {ext: ext}})
validate('hello') // returns true
validate(42) // return falseFiltering away additional properties
is-my-json-valid supports filtering away properties not in the schema
var filter = validator.filter({
required: true,
type: 'object',
properties: {
hello: {type: 'string', required: true}
},
additionalProperties: false
})
var doc = {hello: 'world', notInSchema: true}
console.log(filter(doc)) // {hello: 'world'}Verbose mode outputs the value on errors
is-my-json-valid outputs the value causing an error when verbose is set to true
var validate = validator({
required: true,
type: 'object',
properties: {
hello: {
required: true,
type: 'string'
}
}
}, {
verbose: true
})
validate({hello: 100});
console.log(validate.errors) // {field: 'data.hello', message: 'is the wrong type', value: 100}Greedy mode tries to validate as much as possible
By default is-my-json-valid bails on first validation error but when greedy is set to true it tries to validate as much as possible:
var validate = validator({
type: 'object',
properties: {
x: {
type: 'number'
}
},
required: ['x', 'y']
}, {
greedy: true
});
validate({x: 'string'});
console.log(validate.errors) // [{field: 'data.y', message: 'is required'},
// {field: 'data.x', message: 'is the wrong type'}]Performance
is-my-json-valid uses code generation to turn your JSON schema into basic javascript code that is easily optimizeable by v8.
At the time of writing, is-my-json-valid is the fastest validator when running
If you know any other relevant benchmarks open a PR and I'll add them.
License
MIT
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