Welcome to the standard library of `nushell`!
The standard library is a pure-`nushell` collection of commands to allow anyone to build
complex applications using standardized tools gathered incrementally.
In this library, you might find `rust`-like `assert` commands to write tests, tools to
manipulate paths and strings, etc, etc, ...
## :toolbox: use the standard library in the REPL or in scripts
in order to "import" the standard library to either the interactive [*REPL*][REPL] of
`nushell` or inside some `.nu` script, you might want to use the
[`use`](https://nushell.sh/commands/docs/use.html) command!
```bash
use /path/to/standard_library/std.nu
```
> ### :mag: a concrete example
> - my name is @amtoine and i use the `ghq` tool to manage `git` projects
> > **Note**
> > `ghq` stores any repository inside `$env.GHQ_ROOT` under `///`
> - the path to my local fork of `nushell` is then defined as
> ```bash
> let-env NUSHELL_REPO = ($env.GHQ_ROOT | path join "github.com" "amtoine" "nushell")
> ```
> - and the full path to the standard library is defined as
> ```bash
> let-env STD_LIB = ($env.NUSHELL_REPO | path join "crates" "nu-utils" "standard_library")
> ```
> > see the content of `$env.STD_LIB` :yum:
> > ```bash
> > >_ ls $env.STD_LIB | get name | str replace $env.STD_LIB "" | str trim -l -c "/"
> > ╭───┬───────────╮
> > │ 0 │ README.md │
> > │ 1 │ std.nu │
> > │ 2 │ tests.nu │
> > ╰───┴───────────╯
> > ```
> - finally we can `use` the standard library and have access to the commands it exposes :thumbsup:
> ```bash
> >_ use std.nu
> >_ help std
> Module: std
>
> Exported commands:
> assert (std assert), assert eq (std assert eq), assert ne (std assert ne), match (std match)
>
> This module does not export environment.
> ```
## :pencil2: contribute to the standard library
### :wrench: add new commands
- add new standard commands to [`std.nu`](std.nu), or preferably create a new submodule.
- add associated tests to [`test_std.nu`](tests_std.nu) or preferably to `test_.nu`.
- define a new exported (!) `test_` command
- import the `assert` functions you need at the top of the functions, e.g. `use std.nu "assert eq"`
### :test_tube: run the tests
the following call should return no errors
```bash
nu /path/to/standard_library/tests.nu
```
> #### :mag: a concrete example
> with `STD_LIB` defined as in the example above
> ```bash
> nu ($env.STD_LIB | path join "tests.nu")
> ```
[REPL]: https://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop