class-validator-jsonschema/__tests__/customValidation.test.ts

Convert class-validator-decorated classes into JSON schema

import {
  getMetadataStorage,
  Validate,
  ValidationArguments,
  ValidatorConstraint,
  ValidatorConstraintInterface,
} from 'class-validator'

import { validationMetadatasToSchemas } from '../src'

@ValidatorConstraint()
export class CustomTextLength implements ValidatorConstraintInterface {
  validate(text: string, validationArguments: ValidationArguments) {
    const [min, max] = validationArguments.constraints
    return text.length > min && text.length < max
  }
}

// @ts-ignore: not referenced
class Post {
  @Validate(CustomTextLength, [0, 11])
  title: string
}

// @ts-ignore: not referenced
class InvalidPost {
  @Validate(CustomTextLength, [0, 11])
  titleNumber: number

  @Validate(CustomTextLength, [0, 11])
  titleBoolean: boolean
}

describe('custom validation classes', () => {
  it('uses property type if no additional converter is supplied', () => {
    const schemas = validationMetadatasToSchemas({
      classValidatorMetadataStorage: getMetadataStorage(),
    })
    expect(schemas.Post).toEqual({
      properties: {
        title: { type: 'string' },
      },
      required: ['title'],
      type: 'object',
    })

    expect(schemas.InvalidPost).toEqual({
      properties: {
        titleBoolean: { type: 'boolean' },
        titleNumber: { type: 'number' },
      },
      required: ['titleNumber', 'titleBoolean'],
      type: 'object',
    })
  })

  it('uses additionalConverter to generate schema when supplied', () => {
    const schemas = validationMetadatasToSchemas({
      additionalConverters: {
        CustomTextLength: (meta) => ({
          maxLength: meta.constraints[1] - 1,
          minLength: meta.constraints[0] + 1,
          type: 'string',
        }),
      },
    })

    expect(schemas.Post).toEqual({
      properties: {
        title: { maxLength: 10, minLength: 1, type: 'string' },
      },
      required: ['title'],
      type: 'object',
    })
  })
})