> ## Documentation Index
> Fetch the complete documentation index at: https://docs.solved.gg/llms.txt
> Use this file to discover all available pages before exploring further.

# Build and test

> Native rusty build and test drivers: flags, workspaces, affected mode, and scripts.

`rusty build`, `run`, `check`, and `test` use the **native rustc graph** by default. They do not fall back to cargo when the graph is unsupported.

## Build

```bash theme={null}
rusty build
rusty build -p PKG --workspace
rusty build --bin NAME
rusty build --features a,b
rusty build --no-default-features
rusty build --all-features
rusty build path.rs                 # single-file compile (skips package scripts)
```

### Affected builds

```bash theme={null}
rusty build --affected [BASE]         # path-touched packages + reverse dependents
rusty build --affected-direct [BASE]  # path-touched packages only
```

`BASE` is a git ref (default behavior matches workspace affected tooling). Useful in CI monorepos.

### Parallelism

```bash theme={null}
rusty build -j 16
# or
export RUSTY_JOBS=16
```

### Lifecycle scripts

If `rusty.json` defines `scripts.build`, that entry can fully override the built-in driver. Otherwise rusty runs:

1. optional `prebuild`
2. **native** build
3. optional `postbuild`

Disable script hooks with `RUSTY_NO_SCRIPTS=1` or `--no-scripts` where supported.

## Run and check

Same native constraints as build:

```bash theme={null}
rusty run
rusty check
```

## Test

```bash theme={null}
rusty test
rusty test [FILTER]...
rusty test -p PKG --workspace
rusty test --affected [base]
rusty test --affected-direct [base]
rusty test -j N
rusty test --shard k/n              # 1-based CI shard
rusty test --reporter junit=PATH
rusty test --retries N
```

Policy: **never cargo by default**. Optional `scripts.test` can override the whole verb when you opt in via config.

Test binary caching is on unless `RUSTY_TEST_CACHE=0`.

## Lint and format

Not built-in clippy/rustfmt drivers under these names:

```bash theme={null}
rusty lint      # requires scripts.lint
rusty format    # requires scripts.format
```

Cargo-flavored tools remain available as **interop** (need cargo on PATH):

```bash theme={null}
rusty clippy
rusty fmt
```

Prefer scripts for reproducible monorepo policy.

## When native fails

If the project shape is outside the `canHandle` matrix, rusty prints a hard error. Fix the project shape, extend support (for contributors), or use a script override intentionally — do not expect a silent cargo path for `build` / `test` on rusty-format.


## Related topics

- [CLI reference](/rusty/0.0.1-dev/reference/cli.md)
- [Workspaces](/rusty/0.0.1-dev/guides/workspaces.md)
- [Environment variables](/rusty/0.0.1-dev/reference/environment.md)
- [Introduction](/rusty/0.0.1-dev/index.md)
- [Project formats](/rusty/0.0.1-dev/concepts/project-formats.md)