Deno 1.10, the latest release of the security-oriented runtime for JavaScript and TypeScript, brings several significant enhancements, including an overhaul to the built-in test runner and the addition of the Web Storage API. Released on May 11, this update introduces new features aimed at improving both performance and developer experience.
One of the most notable changes in Deno 1.10 is the update to the deno test command. In this version, test modules are executed in isolation, each using a new instance of the runtime. This is a departure from previous versions, where tests were run sequentially within a single runtime instance. The update also adds support for the --jobs flag, which allows developers to specify the number of threads to use during test execution. By default, tests will still run serially, but this option provides more flexibility for parallel testing when needed.
In addition to the test runner improvements, Deno 1.10 introduces several other valuable features. For instance, tests can now be run with configurable permissions through a new permissions option. The update also includes support for type-checking code examples found in documentation comments using the --doc flag, further ensuring code correctness. Another helpful addition is the --watch flag, which allows the test runner to monitor file changes and automatically re-run relevant test cases, making the development process smoother and more efficient.
Looking ahead, Deno has plans to expand its testing capabilities even further. Future releases will include support for running code examples as standard tests, providing additional functionality for developers working with documentation and ensuring that code remains up to date and functional. Overall, Deno 1.10 marks a significant step forward in refining the testing experience while also introducing practical new tools to streamline development workflows.