@asyncapi/keeper

AsyncAPI message payload validation library that validates messages against JSON Schema (Draft-07).

Installation

npm install @asyncapi/keeper

API

await compileSchemas(schemas)

Parameters

| Parameter | Type | Description | Required | |-----------|--------------------|-----------------------------------------------------------------------------|----------| | schemas | Array<Object> | Array of JSON Schema Draft-07 objects representing valid message structures | Yes |

Returns

Promise<Array<function>> — Array of compiled schema validator functions.

await compileSchemasByOperationId(asyncapiFilepath, operationId)

Parameters

| Parameter | Type | Description | Required | |---------------------|--------------|---------------------------------------------------------------------------------------------|----------| | asyncapiFilepath | string | Path to the AsyncAPI document file. | Yes | | operationId | string | The ID of the operation to extract message schemas from. | Yes |

Returns

Promise<Array<function>> — Array of compiled schema validator functions for the operation's messages.

validateMessage(compiledSchemas, message)

Parameters

| Parameter | Type | Description | Required | |------------------|--------------------|-----------------------------------------------------------------------------|----------| | compiledSchemas| Array<function> | Array of compiled schema validator functions | Yes | | message | any | The message payload to validate (any non-null value) | Yes |

Returns

{ isValid: boolean, validationErrors?: Array<object> } — Object containing validation result and errors if invalid.

removeCompiledSchemas()

Returns

void — Unregisters all currently registered schemas from the validator.

Usage

Basic Schema Compilation and Validation

import { compileSchemas, validateMessage, removeCompiledSchemas } from '@asyncapi/keeper';

// Example schemas (JSON Schema Draft-07 objects)
const schemas = [
  {
    type: 'object',
    properties: {
      content: { type: 'string' },
      timestamp: { type: 'string', format: 'date-time' }
    },
    required: ['content', 'timestamp'],
    additionalProperties: false
  },
  {
    type: 'object',
    properties: {
      content: { type: 'string' }
    },
    required: ['content'],
    additionalProperties: false
  }
];

// Compile schemas
const compiledSchemas = await compileSchemas(schemas);

// Validate messages
const message1 = { content: 'Hello', timestamp: '2024-05-01T12:00:00Z' };
const result1 = validateMessage(compiledSchemas, message1);
console.log('Valid:', result1.isValid); // true
console.log('Errors:', result1.validationErrors); // undefined

const message2 = { content: 42 }; // Invalid: content should be string
const result2 = validateMessage(compiledSchemas, message2);
console.log('Valid:', result2.isValid); // false
console.log('Errors:', result2.validationErrors); // Array of validation errors

// Clean up
removeCompiledSchemas();

Operation-Specific Validation

import { compileSchemasByOperationId, validateMessage, removeCompiledSchemas } from '@asyncapi/keeper';
import path from 'path';

const asyncapiFilepath = path.resolve(__dirname, './asyncapi.yaml'); // Path to your AsyncAPI document
const operationId = 'sendHelloMessage'; // The operationId to validate against

// Compile schemas for specific operation
const compiledSchemas = await compileSchemasByOperationId(asyncapiFilepath, operationId);

// Validate message against operation schemas
const message = { content: 'Hello from operation' };
const result = validateMessage(compiledSchemas, message);
console.log('Valid for operation:', result.isValid); // true or false

// Clean up
removeCompiledSchemas();