@cucumber/messages

What is @cucumber/messages?

The @cucumber/messages package is designed to provide a protocol for communication between different components of the Cucumber testing tool. It defines a set of message formats that can be used for representing test cases, test results, and other information in a standardized way. This facilitates interoperability between different parts of the Cucumber ecosystem, such as between the Cucumber framework itself and various plugins or integrations.

What are @cucumber/messages's main functionalities?

Serialization and Deserialization of Messages

This feature allows for the serialization and deserialization of Cucumber messages. It's useful for transmitting test results over a network or storing them in a file. The code sample demonstrates how to create an Envelope message, serialize it to a binary format, and then deserialize it back to a message object.

"use strict";
const { messages } = require('@cucumber/messages');
const { Envelope } = messages;
const envelope = Envelope.fromObject({ testStepFinished: { testStepResult: { status: 'PASSED' } } });
const serialized = Envelope.encode(envelope).finish();
const deserialized = Envelope.decode(serialized);

Creating and Working with Messages

This feature involves creating and manipulating various types of messages defined by the package, such as test cases, test steps, and results. The code sample shows how to create a TestCase message with specific properties.

"use strict";
const { messages } = require('@cucumber/messages');
const { TestCase } = messages;
const testCase = TestCase.create({ id: '1', pickleId: '2' });
console.log(testCase);

Other packages similar to @cucumber/messages

gherkin

The 'gherkin' package is used for parsing Gherkin files, which are plain text files that describe features and scenarios for Cucumber tests. While 'gherkin' focuses on parsing the feature files, '@cucumber/messages' is more about defining a standard format for the messages that flow between different components of the Cucumber ecosystem. Both packages are part of the broader Cucumber framework but serve different roles.

chai

The 'chai' package is a popular assertion library that can be used in conjunction with testing frameworks like Mocha or Cucumber. Unlike '@cucumber/messages', which is focused on the messaging protocol within the Cucumber ecosystem, 'chai' provides a rich set of assertions for writing test cases. It's more about enhancing the test writing experience rather than facilitating communication between Cucumber components.

README

Cucumber Messages for JavaScript (Protocol Buffers)

Changelog

[14.0.0] - 2021-02-05

Changed

• [JavaScript] The stream classes have to be imported separately: import { MessageToBinaryStream, MessageToNdjsonStream, BinaryToMessageStream, NdjsonToMessageStream} from '@cucumber/dist/src/stream' (#1331)
• In JavaScript, Int64 fields are now typed as number, rather than number|Long

Fixed

• [JavaScript] removed circular dependencies. (#1292 davidjgoss)