# Boost Your Rust 🦀 Development with Hot Reload using cargo-watch

## Motivation

Most of the developers with a `node.js` background are pretty familiar with the package called `nodemon`.

%[https://github.com/remy/nodemon] 

`nodemon` is a tool is automatically restarting the node application whenever we change a file in a directory. This is tremendously useful during development, as we don't have to restart the application manually every time we make a change. And as we all know, we developers are lazy!

Or you may be familiar with the tool called `entr`, which is a command-line tool that runs arbitrary commands when files change.

%[https://github.com/eradman/entr] 

In this blog article, I will show you a similar command-line tool with the same productivity boost but for Rust. This tool is called `cargo-watch`.

%[https://github.com/watchexec/cargo-watch] 

## What is `cargo-watch`?

`cargo-watch` watches your Rust project for any changes and runs cargo commands when a change is detected. The installation is very simple, just run the following command:

```shell
cargo install cargo-watch
```

### Usage examples

The simplest usage of `cargo-watch` is to run the `cargo run` command whenever a file in the current directory changes:

```shell
cargo watch -x run
```

If you want to run multiple commands, you can use the `-x` flag multiple times. In the following example, we will run the `cargo test` and `cargo run` commands whenever a file in the current directory changes:

```shell
cargo watch -x test -x run
```

If you want to suppress the output of the `cargo run` command, you add the `-q` flag to the `cargo run` command:

```shell
cargo watch -x test -x 'run -q'
```

With the `-w` flag, you can specify a directory to watch. In the following example, we will watch the `src` directory for changes:

```shell
cargo watch -w src/ -x test -x 'run -q'
```

### Ignoring files and directories

`cargo-watch` ignores per default all files and directories listed in the `.gitignore` file. With the flag `--no-vcs-ignores` you can disable this behavior. Secondly, `cargo-watch` ignores all files and directories that are listed in the `.ignore` file. With the flag `--no-dot-ignores` you can also disable this behavior.

Additionally, you can ignore files and directories by using the `-i` flag. This uses the [Glob pattern matching syntax](https://watchexec.github.io/docs/glob-patterns.html).

## Conclusion

With `cargo-watch` we have a similar tool by hand, which we are already familiar from other programming languages.  
  
I use this tool every day and I can highly recommend it! The boost in your development productivity will be huge!