<!--
if this PR closes one or more issues, you can automatically link the PR
with
them by using one of the [*linking
keywords*](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword),
e.g.
- this PR should close #xxxx
- fixes #xxxx
you can also mention related issues, PRs or discussions!
-->
# Description
<!--
Thank you for improving Nushell. Please, check our [contributing
guide](../CONTRIBUTING.md) and talk to the core team before making major
changes.
Description of your pull request goes here. **Provide examples and/or
screenshots** if your changes affect the user experience.
-->
# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
# Tests + Formatting
<!--
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used` to
check that you're using the standard code style
- `cargo test --workspace` to check that all tests pass (on Windows make
sure to [enable developer
mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
- `cargo run -- -c "use toolkit.nu; toolkit test stdlib"` to run the
tests for the standard library
> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->
# After Submitting
<!-- If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
-->
# Description
playing with the NUON format in Rust code in some plugins, we agreed
with the team it was a great time to create a standalone NUON format to
allow Rust devs to use this Nushell file format.
> **Note**
> this PR almost copy-pastes the code from
`nu_commands/src/formats/from/nuon.rs` and
`nu_commands/src/formats/to/nuon.rs` to `nuon/src/from.rs` and
`nuon/src/to.rs`, with minor tweaks to make then standalone functions,
e.g. remove the rest of the command implementations
### TODO
- [x] add tests
- [x] add documentation
# User-Facing Changes
devs will have access to a new crate, `nuon`, and two functions,
`from_nuon` and `to_nuon`
```rust
from_nuon(
input: &str,
span: Option<Span>,
) -> Result<Value, ShellError>
```
```rust
to_nuon(
input: &Value,
raw: bool,
tabs: Option<usize>,
indent: Option<usize>,
span: Option<Span>,
) -> Result<String, ShellError>
```
# Tests + Formatting
i've basically taken all the tests from
`crates/nu-command/tests/format_conversions/nuon.rs` and converted them
to use `from_nuon` and `to_nuon` instead of Nushell commands
- i've created a `nuon_end_to_end` to run both conversions with an
optional middle value to check that all is fine
> **Note**
> the `nuon::tests::read_code_should_fail_rather_than_panic` test does
give different results locally and in the CI...
> i've left it ignored with comments to help future us :)
# After Submitting
mention that in the release notes for sure!!