Using the NestJS REPL environment

The article explores the Read-Eval-Print Loop (REPL) environment, specifically focusing on the NestJS REPL, which was introduced in NestJS version 9 as a tool to interact with NestJS applications from the command line. It explains how to set up and use the NestJS REPL environment, highlighting its ability to inspect application dependency graphs and invoke methods on providers and controllers. The article also describes various native functions available within the NestJS REPL, such as `get`, `debug`, `resolve`, and `select`, and how these can be utilized for efficient testing and interaction with NestJS applications. Furthermore, it discusses how the built-in Node REPL environment can complement the functionalities of the NestJS REPL by offering features like saving evaluated commands to a file and entering editor mode for multi-line code execution. The piece underscores the benefits of using both REPL environments together to maximize their capabilities in development tasks.