webdriverio/expect-webdriverio

expect-webdriverio is an assertion library for WebdriverIO that brings expect-style matchers to browser automation testing.

The library solves the problem of writing clear, readable assertions in WebdriverIO tests by providing an expect-based API inspired by the popular expect package. Its key approach is to automatically wait for expectations to succeed rather than failing immediately, which handles the asynchronous nature of browser interactions. It supports both single elements and multiple elements, works across multi-remote browser scenarios where different assertions can apply to different browser instances, and generates detailed error messages that show the full element selector, actual versus expected values, and highlighted differences for text comparisons.

Teams should adopt this tool if they are building WebdriverIO test suites and prefer the expect syntax over WebdriverIO's native assertion methods. It works across multiple test frameworks including Mocha, Cucumber, Jest, and Jasmine, and provides built-in TypeScript types for autocomplete support. The library is designed to work both through the WDIO testrunner, where expect is automatically available globally, and in standalone mode where it must be explicitly imported. It also supports the Browser Runner for component testing with frameworks like React, Vue.js, and Svelte, though with some known limitations in that context.

The project maintains active development with ongoing work toward a new major version. The codebase is written in TypeScript and includes comprehensive documentation covering API details, multi-element and multi-remote scenarios, framework integration, custom matcher extension, and migration guidance. The test suite runs automatically on changes, and the project welcomes community contributions through issues and pull requests.