The Validation and Serialization documentation outlines all parameters accepted by Fastify to set up JSON Schema Validation in order to validate the input, and JSON Schema Serialization in order to optimize the output.
fluent-schema
can be used to simplify this task while allowing the reuse of constants.
const S = require('fluent-schema')
// You can have an object like this, or query a DB to get the values
const MY_KEY = {
KEY1: 'ONE',
KEY2: 'TWO'
}
const bodyJsonSchema = S.object()
.prop('someKey', S.string())
.prop('someOtherKey', S.number())
.prop('requiredKey', S.array().maxItems(3).items(S.integer()).required())
.prop('nullableKey', S.mixed([S.TYPES.NUMBER, S.TYPES.NULL]))
.prop('multipleTypesKey', S.mixed([S.TYPES.BOOLEAN, S.TYPES.NUMBER]))
.prop('multipleRestrictedTypesKey', S.oneOf([S.string().maxLength(5), S.number().minimum(10)]))
.prop('enumKey', S.enum(Object.values(MY_KEYS)))
.prop('notTypeKey', S.not(S.array()))
const queryStringJsonSchema = S.object()
.prop('name', S.string())
.prop('excitement', S.integer())
const paramsJsonSchema = S.object()
.prop('par1', S.string())
.prop('par2', S.integer())
const headersJsonSchema = S.object()
.prop('x-foo', S.string().required())
// Note that there is no need to call `.valueOf()`!
const schema = {
body: bodyJsonSchema,
querystring: queryStringJsonSchema, // (or) query: queryStringJsonSchema
params: paramsJsonSchema,
headers: headersJsonSchema
}
fastify.post('/the/url', { schema }, handler)
With fluent-schema
you can manipulate your schemas in an easier and programmatic way and then reuse them
thanks to the addSchema()
method. You can refer to the schema in two different manners that are detailed
in the Validation-and-Serialization.md documentation.
Here are some usage examples:
$ref-way
: refer to an external schema.
const addressSchema = S.object()
.id('#address')
.prop('line1').required()
.prop('line2')
.prop('country').required()
.prop('city').required()
.prop('zipcode').required()
const commonSchemas = S.object()
.id('https://fastify/demo')
.definition('addressSchema', addressSchema)
.definition('otherSchema', otherSchema) // You can add any schemas you need
fastify.addSchema(commonSchemas)
const bodyJsonSchema = S.object()
.prop('residence', S.ref('https://fastify/demo#address')).required()
.prop('office', S.ref('https://fastify/demo#/definitions/addressSchema')).required()
const schema = { body: bodyJsonSchema }
fastify.post('/the/url', { schema }, handler)
replace-way
: refer to a shared schema to replace before the validation process.
const sharedAddressSchema = {
$id: 'sharedAddress',
type: 'object',
required: ['line1', 'country', 'city', 'zipcode'],
properties: {
line1: { type: 'string' },
line2: { type: 'string' },
country: { type: 'string' },
city: { type: 'string' },
zipcode: { type: 'string' }
}
}
fastify.addSchema(sharedAddressSchema)
const bodyJsonSchema = {
type: 'object',
properties: {
vacation: 'sharedAddress#'
}
}
const schema = { body: bodyJsonSchema }
fastify.post('/the/url', { schema }, handler)
NB: you can mix up the $ref-way
and the replace-way
when using fastify.addSchema
.