Redocly Linting rule to ensure that each operation has only one 2xx response.' (Generated from HuggingChat)

only_one_2xx_response.js

const { RuleTester } = require('eslint');
const openApiParser = require('openapi-parser');

// Define the linting rule
const rule = {
  meta: {
    docs: {
      description: 'Ensure an API operation has at most one 2xx response',
      category: 'Best Practices',
      recommended: true,
    },
    schema: [], // No additional configuration needed for this rule
    type: 'problem', // This is a problem/error reporting rule
  },
  create: (context) => ({
    PathItemObject: (node) => {
      const pathResponses = node?.responses || {};
      let twoXXCount = 0;

      Object.entries(pathResponses).forEach(([code, response]) => {
        if (+code >= 200 && +code <= 299) {
          twoXXCount++;
          if (twoXXCount > 1) {
            context.report({
              node,
              message: `Path "${node.key}" must not contain more than one 2xx status code response. Found ${code}.`,
            });
          }
        }
      });
    },
  }),
};

// Set up the RuleTester
const rtl = new RuleTester({
  parserOptions: { ecmaVersion: 6, sourceType: 'module' },
});

rtl.run('only_one_2xx_response', rule, {
  valid: [{ filename: 'valid.yaml', code: '' }],
  invalid: [
    {
      filename: 'invalid.yaml',
      code: `
openapi: "3.0.0"
paths:
  /example:
    get:
      responses:
        200: {}
        201: {}
`,
    },
  ],
});

File to test with:

openapi: 3.0.0
info:
  title: Test API
  version: 1.0.0
servers:
  - url: https://test.com/api
paths:
  /example:
    get:
      summary: Example GET request
      description: An example endpoint with multiple 2xx responses
      responses:
        200:
          description: Successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ExampleResponse'
        201:
          description: Created resource
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CreatedResource'
components:
  schemas:
    ExampleResponse:
      type: object
      properties:
        id:
          type: string
          example: abcdefg
    CreatedResource:
      type: object
      properties:
        createdAt:
          type: string
          format: date-time
          example: 2022-05-04T18:17:41Z