Deno 1.10 overhauls test runner

Latest version of the JavaScript and TypeScript runtime introduces the ability to run test modules in isolation, along with other testing improvements.

Editor at Large, InfoWorld |

Deno 1.10 overhauls test runner — Thinkstock

Deno 1.10, the latest version of the security-focused runtime for JavaScript and TypeScript, improves the built-in test runner and adds a Web Storage API. The update was published May 11.

In Deno 1.10, the deno test test runner runs discovered test modules in isolation using a new instance of the runtime for each module. Previously, Deno ran tests serially inside a single runtime instance. Further, deno test now supports the --jobs flag to specify how many threads should be used when running tests. Tests still run serially by default.

Deno 1.10 also introduces configurable permissions for tests, using a permissions option; the ability to type check code examples in documentation comments, using the --doc flag; the ability to watch for file changes to re-run relevant test cases, using the --watch flag; and better test runner output. In future releases, support will be added for running code examples as regular tests.

Deno 1.10 follows last month’s release of Deno 1.9. To upgrade to Deno 1.10, users can run deno upgrade. Other improvements in Deno 1.10:

Paul Krill is an editor at large at InfoWorld, whose coverage focuses on application development.