Mock Api

This module is a middleware generating function that generates an API based on a OpenAPI 3 compatible YAML or JSON file. All data returned is generated by chance module.

• Mock Api
  • Install
  • Usage
    • Options
    • Specifying custom Chance options
    • A note on types
    • Returning Fixed Values
    • Mocking headers (new)

Install

yarn add openapi-middleware-mocks or npm install openapi-middleware-mocks

Usage

When installed use it as normal middleware in your express application.

const openApiMockerMiddleware = await openApiMocker({
    openApiFile: 'path/to/file',
})

/*...*/
app.use(bodyParser.json()) // remember to use body parser
app.use(openApiMockerMiddleware)

Options

export interface Config {
    openApiFile?: string
    openApi?: OpenAPIV3.Document
    ignorePaths?: string[]
    mockPaths?: string[]
    format400?: () => {}
    format404?: (next: Function) => {}
}

Specifying custom Chance options

Swagger specifies only a few primitive types; for scenarios where specific chance methods are needed, use the x-chance-type field.

components:
    schemas:
        NewPet:
            properties:
            name:
                type: string
                x-chance-type: name
            tag:
                type: string
                x-chance-type: guid

Most of the chance methods allow some fine-tuning of the returned data. For example, the integer method allows specification of minimum and maximum output values. These options can be configured in the Swagger YAML file with the x-chance-options block:

components:
  schemas:
    Pet:
      allOf:
        - $ref: "#/components/schemas/NewPet"
        - required:
            - id
            properties:
            id:
              type: integer
              format: int64
              x-type-options:
                min: 1
                max: 1000

A note on types

All of the primitive types defined in the OpenApi specification are supported except for file and password. Currently, the format property is ignored; use x-chance-type instead. The server will error on any request with a type other than one of the primitive types if there is no valid x-chance-type also defined.

Returning Fixed Values

Although not a chance method, support has been added for returning fixed values using x-chance-type: fixed. Any value given for the custom tag x-type-value will be returned; below is an example where an object is returned:

status:
    type: object
    x-chance-type: fixed
    x-type-value:
        type: 'adopted'

Pass value to be returned by server

When requesting mocked data you can pass object to modify returning value by definition. Under the hood it uses lodash set function

ex:

'x-force-mock': '{"name": "Burek"}'

returned object will have property with name set to "Burek"

Headers

Version 2.0 introduced headers mocking. From now headers described in schema will be mocked the same way as response.

headers:
    x-int:
        type: integer
        format: int64
        x-type-options:
            min: 1
            max: 1000