Ruby

Ruby support is available through the Ruby extension.

The Ruby extension also provides support for ERB files.

Language Servers

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

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 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 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:

{
  "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:

{
  "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:

{
  "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:

{
  "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:

{
  "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.

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:

{
  "languages": {
    "Ruby": {
      "language_servers": ["ruby-lsp", "!solargraph", "..."]
    }
  },
  "lsp": {
    "ruby-lsp": {
      "initialization_options": {
        "enabledFeatures": {
          // This disables diagnostics
          "diagnostics": false
        }
      }
    }
  }
}

LSP settings and initialization_options can also be project-specific. For example to use standardrb/standard as a formatter and linter for a particular project, add this to a .zed/settings.json inside your project repo:

{
  "lsp": {
    "ruby-lsp": {
      "initialization_options": {
        "formatter": "standard",
        "linters": ["standard"]
      }
    }
  }
}

Setting up rubocop LSP

Rubocop has unsafe autocorrection disabled by default. We can tell Zed to enable it by adding the following to your settings.json:

{
  "languages": {
    "Ruby": {
      // Use ruby-lsp as the primary language server and rubocop as the secondary.
      "language_servers": ["ruby-lsp", "rubocop", "!solargraph", "..."]
    }
  },
  "lsp": {
    "rubocop": {
      "initialization_options": {
        "safeAutocorrect": false
      }
    },
    "ruby-lsp": {
      "initialization_options": {
        "enabledFeatures": {
          "diagnostics": false
        }
      }
    }
  }
}

Using the Tailwind CSS Language Server with Ruby

It's possible to use the Tailwind CSS Language Server in Ruby and ERB files.

In order to do that, you need to configure the language server so that it knows about where to look for CSS classes in Ruby/ERB files by adding the following to your settings.json:

{
  "languages": {
    "Ruby": {
      "language_servers": ["tailwindcss-language-server", "..."]
    }
  },
  "lsp": {
    "tailwindcss-language-server": {
      "settings": {
        "includeLanguages": {
          "erb": "html",
          "ruby": "html"
        },
        "experimental": {
          "classRegex": ["\\bclass:\\s*['\"]([^'\"]*)['\"]"]
        }
      }
    }
  }
}

With these settings you will get completions for Tailwind CSS classes in HTML attributes inside ERB files and inside Ruby/ERB strings that are coming after a class: key. Examples:

# Ruby file:
def method
  div(class: "pl-2 <completion here>") do
    p(class: "mt-2 <completion here>") { "Hello World" }
  end
end

# ERB file:
<%= link_to "Hello", "/hello", class: "pl-2 <completion here>" %>
<a href="/hello" class="pl-2 <completion here>">Hello</a>

Running tests

To run tests in your Ruby project, you can set up custom tasks in your local .zed/tasks.json configuration file. These tasks can be defined to work with different test frameworks like Minitest, RSpec, quickdraw, and tldr. Below are some examples of how to set up these tasks to run your tests from within your editor.

Minitest with Rails

[
  {
    "label": "test $ZED_RELATIVE_FILE -n /$ZED_SYMBOL/",
    "command": "bin/rails test $ZED_RELATIVE_FILE -n /$ZED_SYMBOL/",
    "tags": ["ruby-test"]
  }
]

Note: We can't use args here because of the way quotes are handled.

Minitest

Plain minitest does not support running tests by line number, only by name, so we need to use $ZED_SYMBOL instead:

[
  {
    "label": "-Itest $ZED_RELATIVE_FILE -n /$ZED_SYMBOL/",
    "command": "bundle exec ruby",
    "args": ["-Itest", "$ZED_RELATIVE_FILE", "-n /$ZED_SYMBOL/"],
    "tags": ["ruby-test"]
  }
]

RSpec

[
  {
    "label": "test $ZED_RELATIVE_FILE:$ZED_ROW",
    "command": "bundle exec rspec",
    "args": ["\"$ZED_RELATIVE_FILE:$ZED_ROW\""],
    "tags": ["ruby-test"]
  }
]

quickdraw

[
  {
    "label": "test $ZED_RELATIVE_FILE:$ZED_ROW",
    "command": "bundle exec qt",
    "args": ["\"$ZED_RELATIVE_FILE:$ZED_ROW\""],
    "tags": ["ruby-test"]
  }
]

tldr

[
  {
    "label": "test $ZED_RELATIVE_FILE:$ZED_ROW",
    "command": "bundle exec tldr",
    "args": ["\"$ZED_RELATIVE_FILE:$ZED_ROW\""],
    "tags": ["ruby-test"]
  }
]