A Scala extension for Zed (powered by Metals)

• Coursier
• Install Metals: cs install metals

Note: You need to have the path to metals exported at shell init (e.g. by an entry in ~/.bashrc), as zed does not currently seem to pick up exported environment variables when started from a terminal. So it's not enough to export PATH="$PATH:~/.local/share/coursier/bin" in a shell and run zed from there. It will fail to start Metals in that case (and will not say so in the LSP log; but nothing but syntax highlighting will work then).

You can set Metals user configuration settings in your zed settings.json in lsp.metals.settings. For example, to enable displaying type annotations for inferred types as inlay hints:

{
  "lsp": {
    "metals": {
      "settings": {
        "inlayHints": {
          "inferredTypes": {
            "enable": true
          }
        }
      }
    }
  }
}

You can also set Metals initialization options and Metals server properties in your zed settings.json in lsp.metals.binary.arguments and lsp.metals.initialization_options, respectively.

For example, to enable HTTP server (running on https://localhost:5031 by default) for executing client commands, which currently are not supported by zed directly, you can use:

{
  "lsp": {
    "metals": {
      "binary": {
        "arguments": [
          "-Dmetals.http=on"
        ]
      },
      "initialization_options": {
        "isHttpEnabled": true
      }
    }
  }
}