Skip to main content

Response validation

When a source is backed by an OpenAPI spec, Reqon can check responses against the operation's schema.

Enabling validation​

Set validateResponses: true on the source:

source API from "./spec.yaml" {
  auth: bearer,
  validateResponses: true
}

What gets validated​

Validation runs only for call Source.operationId requests, against the operation's 200 JSON response schema. Plain get/post fetches are not validated, and neither are non-200 responses.

call API.getPetById
// If API has validateResponses: true and getPetById defines a 200 schema,
// the response body is checked against that schema.

Behaviour​

Validation is advisory. When a response doesn't match the schema, Reqon logs warnings (visible with --verbose) and execution continues. It does not throw, abort, or change response, and there's no validationMode option — it always warns and carries on.

For checks that must block the pipeline, use a validate step (see below).

Validation rules​

The validator checks the following against the schema.

Required fields​

Pet:
  required:
    - id
    - name

A response missing name is reported:

{ "id": "123" }  // warning: missing required property 'name'

Type checking​

Pet:
  properties:
    id:
      type: string
    age:
      type: integer
{ "id": 123, "age": "five" }
// warnings: id expected string, age expected integer

Enum​

Pet:
  properties:
    status:
      type: string
      enum: [available, pending, sold]
{ "status": "active" }  // warning: value not in enum

Numeric and string constraints​

minimum/maximum for numbers, and minLength/maxLength/pattern for strings, are all checked.

Arrays​

Pets:
  type: array
  items:
    $ref: '#/components/schemas/Pet'

minItems/maxItems are checked, and each item is validated against the item schema.

Nested objects​

Pet:
  properties:
    owner:
      $ref: '#/components/schemas/Owner'

Nested object properties are validated recursively, including additionalProperties when the schema sets it.

Hard validation with the validate step​

Schema validation only logs. To stop the pipeline on bad data, add a validate step. Each assume is a condition; a failed assumption throws and aborts the mission:

action FetchOrder {
  call API.getOrder

  validate response {
    assume .total >= 0
    assume .items is array
    assume length(.items) > 0
  }

  store response -> orders { key: .id }
}

Programmatic validation​

The validator is also exported for direct use:

import { validateResponse } from 'reqon-dsl';

const result = validateResponse(data, schema);
if (!result.valid) {
  for (const err of result.errors) {
    console.warn(`${err.path}: ${err.message}`);
  }
}

Troubleshooting​

Warnings you didn't expect​

The spec may be out of date with the live API. Update the spec, or check for an API version change.

Validation isn't running​

Confirm all of these:

  • The source is declared with from "./spec.yaml".
  • validateResponses: true is set on the source.
  • You're using call Source.operationId (not a plain get/post).
  • The operation defines a 200 JSON response schema.
  • You're running with --verbose so the warnings are visible.