apollo-server-v2-constraint-directive
v1.0.0
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Check the GraphQL input fields with directives
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apollo-server-constraint-directive
Allows using @constraint as a directive to validate input and output data. This module is for Apollo Server, and support the latest Apollo Server version 2.
It is mainly based on the module from graphql-constraint-directive, which is for Apollo version 1 only. This module is an Inspired by Constraints Directives RFC and OpenAPI
If you are looking for a playground checkout this project apollo-server-playground.
Install
npm install apollo-server-v2-constraint-directive
Usage
const { ApolloServer, makeExecutableSchema, gql } = require('apollo-server')
const ConstraintDirective = require('apollo-server-constraint-directive')
const schemaDirectives = {
constraint: ConstraintDirective,
};
const typeDefs = gql`
scalar ValidateString
scalar ValidateNumber
directive @constraint(
# String constraints
minLength: Int
maxLength: Int
startsWith: String
endsWith: String
notContains: String
pattern: String
format: String
# Number constraints
min: Int
max: Int
exclusiveMin: Int
exclusiveMax: Int
multipleOf: Int
) on INPUT_FIELD_DEFINITION
type Query {
books: [Book]
}
type Book {
title: String
}
type Mutation {
createBook(input: BookInput): Book
}
input BookInput {
title: String! @constraint(minLength: 5, format: "email")
}`
// The ApolloServer constructor
const server = new ApolloServer({
schema: makeExecutableSchema({ typeDefs, schemaDirectives })
})
// The `listen` method launches a web server.
server.listen().then(({ url }) => {
console.log(`🚀 Server ready at ${url}`)
})
API
String
minLength
@constraint(minLength: 5)
Restrict to a minimum length
maxLength
@constraint(maxLength: 5)
Restrict to a maximum length
startsWith
@constraint(startsWith: "foo")
Ensure value starts with foo
endsWith
@constraint(endsWith: "foo")
Ensure value ends with foo
contains
@constraint(contains: "foo")
Ensure value contains foo
notContains
@constraint(notContains: "foo")
Ensure value does not contain foo
pattern
@constraint(pattern: "^[0-9a-zA-Z]*$")
Ensure value matches regex, e.g. alphanumeric
format
@constraint(format: "email")
Ensure value is in a particular format
Supported formats:
- byte: Base64
- date-time: RFC 3339
- date: ISO 8601
- ipv4
- ipv6
- uri
- uuid
password strength
@constraint(passwordScore: 3)
Ensure password value has estimated strength. zxcvbn is used under the hood. Possible strength values are between 1 and 5. Heigher is better
Int/Float
min
@constraint(min: 3)
Ensure value is greater than or equal to
max
@constraint(max: 3)
Ensure value is less than or equal to
exclusiveMin
@constraint(exclusiveMin: 3)
Ensure value is greater than
exclusiveMax
@constraint(exclusiveMax: 3)
Ensure value is less than
multipleOf
@constraint(multipleOf: 10)
Ensure value is a multiple
ConstraintDirectiveError
Each validation error throws a ConstraintDirectiveError
. Combined with a formatError function, this can be used to customise error messages.
{
code: 'BAD_USER_INPUT',
fieldName: 'theFieldName',
context: [ { arg: 'argument name which failed', value: 'value of argument' } ]
}
const formatError = function (error) {
if (error.originalError && error.originalError && error.originalError.originalError && error.originalError.originalError.code === 'BAD_USER_INPUT') {
// return a custom object
}
return error
}
const apollo = new ApolloServer({
schema: makeExecutableSchema({ typeDefs, schemaDirectives }),
formatError
});