# Ruby

Ruby support is available through the [Ruby extension](https://github.com/zed-extensions/ruby).

- Tree-sitters:
  - [tree-sitter-ruby](https://github.com/tree-sitter/tree-sitter-ruby)
  - [tree-sitter-embedded-template](https://github.com/tree-sitter/tree-sitter-embedded-template)
- Language Servers:
  - [ruby-lsp](https://github.com/Shopify/ruby-lsp)
  - [solargraph](https://github.com/castwide/solargraph)
  - [rubocop](https://github.com/rubocop/rubocop)

The Ruby extension also provides support for ERB files.

## Language Servers

There are multiple language servers available for Ruby. Zed supports the two following:

- [solargraph](https://github.com/castwide/solargraph)
- [ruby-lsp](https://github.com/Shopify/ruby-lsp)

They both have an overlapping feature set of autocomplete, diagnostics, code actions, etc. and it's up to you to decide which one you want to use. Note that you can't use both at the same time.

In addition to these two language servers, Zed also supports [rubocop](https://github.com/rubocop/rubocop) which is a static code analyzer and linter for Ruby. Under the hood, it's also used by Zed as a language server, but its functionality is complimentary to that of solargraph and ruby-lsp.

When configuring a language server, it helps to open the LSP Logs window using the 'dev: Open Language Server Logs' command. You can then choose the corresponding language instance to see any logged information.

## Configuring a language server

The [Ruby extension](https://github.com/zed-extensions/ruby) offers both `solargraph` and `ruby-lsp` language server support.

### Language Server Activation

For all Ruby language servers (`solargraph`, `ruby-lsp`, and `rubocop`), the Ruby extension follows this activation sequence:

1. If the language server is found in your project's `Gemfile`, it will be used through `bundle exec`.
2. If not found in the `Gemfile`, the Ruby extension will look for the executable in your system `PATH`.
3. If the language server is not found in either location, the Ruby extension will automatically install it as a global gem (note: this will not install to your current Ruby gemset).

You can skip step 1 and force using the system executable by setting `use_bundler` to `false` in your settings:

```jsonc
{
  "lsp": {
    "<SERVER_NAME>": {
      "settings": {
        "use_bundler": false,
      },
    },
  },
}
```

### Using `solargraph`

`solargraph` is enabled by default in the Ruby extension.

### Using `ruby-lsp`

To switch to `ruby-lsp`, add the following to your `settings.json`:

```json
{
  "languages": {
    "Ruby": {
      "language_servers": ["ruby-lsp", "!solargraph", "!rubocop", "..."]
    }
  }
}
```

That disables `solargraph` and `rubocop` and enables `ruby-lsp`.

### Using `rubocop`

The Ruby extension also provides support for `rubocop` language server for offense detection and autocorrection.

To enable it, add the following to your `settings.json`:

```json
{
  "languages": {
    "Ruby": {
      "language_servers": ["ruby-lsp", "rubocop", "!solargraph", "..."]
    }
  }
}
```

Or, conversely, you can disable `ruby-lsp` and enable `solargraph` and `rubocop` by adding the following to your `settings.json`:

```json
{
  "languages": {
    "Ruby": {
      "language_servers": ["solargraph", "rubocop", "!ruby-lsp", "..."]
    }
  }
}
```

## Setting up `solargraph`

Solargraph has formatting and diagnostics disabled by default. We can tell Zed to enable them by adding the following to your `settings.json`:

```json
{
  "lsp": {
    "solargraph": {
      "initialization_options": {
        "diagnostics": true,
        "formatting": true
      }
    }
  }
}
```

### Configuration

Solargraph reads its configuration from a file called `.solargraph.yml` in the root of your project. For more information about this file, see the [Solargraph configuration documentation](https://solargraph.org/guides/configuration).

## Setting up `ruby-lsp`

Ruby LSP uses pull-based diagnostics which Zed doesn't support yet. We can tell Zed to disable it by adding the following to your `settings.json`: