builtin-mocking.md

Using the Built-in Mocking

For each API end point FLAT can generate a mock response with the status code 200 from the respective OpenAPI examples section:

paths:
  /:
    get:
      responses:
        200:
          examples:
            application/json:
              foo: bar
              baz: qux

Or, written as JSON object (Mind the indentation of }!):

…
          examples:
            application/json: {
                "foo": "bar",
                "baz": "qux"
              }

To improve readability, larger objects are better put in the OpenAPI definitions section or even into external JSON files:

…
          examples:
            application/json:
              $ref: "#/definitions/Example"
…
definitions:
  Example:
    foo: bar
    baz: qux

or

…
          examples:
            application/json:
              $ref: example.json

Sending the request header Mock: true tells FLAT to respond with a mock:

$ curl -i -H Mock:true localhost:8080
…
Mock: true
Content-Type: application/json

{"foo":"bar","baz":"qux"}

Such a mock response always identifies itself with a Mock: true response header line.

A fitting mock response body will be picked from the examples section according to the submitted Accept header – with application/json being the default.

Mock responses will be validated, if response validation is enabled in swagger.yaml.