Elm Plugin for Visual Studio Code (VSCode)

Supports elm 0.19 and up

Install

Install VSCode from here
Follow this link to install the plugin
Make sure you have nodejs and therefore npm installed
Make sure you have Elm installed
Install elm-test and elm-format by running npm install -g elm-test elm-format in a terminal

Highlighted Features

Errors and informations when changing code and when saving (Control + S)
Format on save (Control + S)
Suggests completions and snippets (Control + Space)

Additional Features

Lists all references to a type alias, module, custom type or function (Alt + Shift + F12)
Jump to the definition of a type alias, module, custom type or function
Shows type annotations and documentation on hover for type alia, module, custom type or function
Rename a type alias, module, custom type or function (F2)
Browse file by symbols (Control + Shift + O)
Browse workspace by symbols (Control + Shift + R)
Codelenses show how many times you calling a function and if it's exposed or not
Code folding
Type inference
Some more

Extension Settings

This extension contributes the following settings:

elmLS.trace.server: Enable/disable trace logging of client and server communication
elmLS.elmPath: The path to your elm executable.
elmLS.elmFormatPath: The path to your elm-format executable.
elmLS.elmTestPath: The path to your elm-test executable.
elmLS.disableElmLSDiagnostics: Disable linting diagnostics from the language server.
elmLS.skipInstallPackageConfirmation: Skip confirmation for the Install Package code action.
elmLS.onlyUpdateDiagnosticsOnSave: Only update compiler diagnostics on save, not on document change.

Configuration

Create an elm-tooling.json file next to your elm.json to configure your project.

Currently there’s just one thing that you can configure: entrypoints. We run elm make to get errors. Without this elm make is run on the current file only. To get errors for the entire project you can specify your entrypoint files – basically, those with main = in them. Then the language server will run elm make on those instead.

Example:

{
  "entrypoints": ["./src/Main.elm"]
}

The entrypoints are relative to the directory where your elm.json and elm-tooling.json is and must start with ./.

Check out the elm-tooling CLI for creating and validating your elm-tooling.json!

FAQ

How to get a logfile?
- F1 -> Type Output: Focus on Output View -> In the now open panel, use the drop down on the right to choose Elm (your project name)
Most features don't seem to work for me?
- This tool needs a valid elm project, please check if you have an elm.json. You can easily initialize your project with elm init. If it still does work, please try if you get the same behavior with the elm-spa-example.
What's the relation to the language server?
- This vscode extension is including the elm-language-server which enables most of the used features.
Why do I need to install elm, elm-test and elm-format?
- You will need to install elm and elm-test to get all diagnostics and elm-format for formatting. If your setup fails to find the global installations of those, you can use the settings panel in VSCode to set the paths to the executable manually. Alternatively you can also just install these to your local npm package.json.
I don't like the inserted lines for "X references" (CodeLenses)
- You can configure VSCode to not show them, just look for "Editor: Code Lens" in your settings.
I'm using glsl and the extension is not helpful
- You need to additionally install vscode-glsllint

Contributing / Debugging

git clone --recursive git@github.com:elm-tooling/elm-language-client-vscode.git
cd elm-language-client-vscode
npm install

Open VSCode with this project (code .) and press F5 to start debugging the plugin.

Strepto / elm-language-client-vscode