power-assert

Power Assert in JavaScript v1.6.1 (stable, released 2017). Provides descriptive assertion messages via the standard Node.js assert interface. No API is the best API – you only need assert(any_expression). Requires code transformation (via Babel, browserify, webpack, etc.) to generate detailed failure messages. Differentiated from chai/should by reusing the native assert module; you can swap require('power-assert') for require('assert') with zero API change. Works server-side and browser-side. Maintained by the original author but has been stable with infrequent releases.