ElixirLS: Elixir support and debugger for VS Code
Provides Elixir language support and debugger. This extension is powered by the Elixir Language Server (ElixirLS), an Elixir implementation of Microsoft's IDE-agnostic Language Server Protocol and VS Code debug protocol. Visit its page for more information. For a guide to debugger usage in Elixir, read this blog post.
- Auto-completion (note that it is not possible to get autocomplete on a variable since we don't have that type of type info)
- Debugger support (requires Erlang >= OTP 19)
- Automatic, incremental Dialyzer analysis (requires Erlang OTP 20)
- Automatic suggestion for @spec annotations based on Dialyzer's inferred success typings
- Inline reporting of build warnings and errors (requires Elixir >= 1.7)
- Code completion
- Smart automatic closing of code blocks
- Documentation lookup on hover
- Code formatter (requires Elixir >= 1.7. Triggered by
Alt + Shift + F hotkey or enabling
- Find references to functions and modules (Thanks to @mattbaker)
- Quick symbol lookup in file (Thanks to @mattbaker)
This is now the main vscode-elixir-ls repo
The elixir-lsp/vscode-elixir-ls repo began as a fork when the original repo at JakeBecker/vscode-elixir-ls became inactive for an extended period of time. So we decided to start an active fork to merge dormant PR's and fix issues where possible. We also believe in an open and shared governance model to share the work instead of relying on one person to shoulder the whole burden.
The original repository has now been deprecated in favor of this one. Future updates to the original VS Code ElixirLS extension will come from this repo.
ElixirLS is opinionated and sets the following default settings for Elixir files:
// Based on Elixir formatter's style
// Provides smart completion for "do" and "fn ->" blocks. Does not run the Elixir formatter.
You can, of course, change them in your user settings, or on a per project basis in
Add support for emmet
emmet is a plugin that makes it easier to write html: https://code.visualstudio.com/docs/editor/emmet
Open VSCode and hit Ctrl+Shift+P (or Cmd+Shift+P) and type "Preference: Open Settings (JSON)"
Add or edit your
emmet.includedLanguages to include the new Language Id:
See ElixirLS for details on the supported Elixir and Erlang versions.
If you run into issues with the extension then try these debugging steps:
- Restart your editor (which will restart ElixirLS) sometimes fixes issues
- Stop your editor, remove the entire
.elixir_ls directory, then restart your editor
- NOTE: This will cause you to have to re-run the entire dialyzer build
If you are seeing the message "Invalid beam file or no abstract code", you need to make sure that your Mix project is set to use the
elixirc compiler option
--debug-info, which can be done by adding the following line to your
elixirc_options: [debug_info: Mix.env() == :dev]
defmodule MyApp.MixProject do
def project do
elixir: "~> 1.7",
elixirc_options: [debug_info: Mix.env() == :dev],
Check ElixirLS Output
Check the output log by opening
View > Output and selecting "ElixirLS" in the dropdown.
Check the developer console by opening
Help > Toggle Developer Tools and include any errors that look relevant.
Test code lenses
This feature allows ElixirLS to provide code lenses that help developers easily execute tests. This feature is currently
experimental because of a few known issues as well as a lack of large scale testing.
// Enable or disable test lenses. Defaults to false.
- The generated command sometimes fails to properly execute tests in umbrella apps. See this comment for more details.
# Clone this repo recursively to ensure you get the elixir-ls submodule
git clone --recursive email@example.com:elixir-lsp/vscode-elixir-ls.git
# Fetch vscode-elixir-ls dependencies
# Fetch elixir-ls dependencies
asdf install # required for asdf users, or remove .tool-versions to use global asdf settings
To launch the extension from VS Code, run the "Launch Extension" launch configuration from Run view or press F5.
Alternatively, you can build and install the extension locally using
vsce command and
# Navigate to vscode-elixir-ls project root
# Build the extension
npx vsce package
# Install it locally
code --install-extension *.vsix --force
Note that if you have the extension installed from the Visual Studio Marketplace and are also installing a locally
built package, you may need to disable the Extensions: Auto Check Updates setting to prevent your
local install from being replaced with the Marketplace version.
Most of the functionality of this extension comes from ElixirLS which is included as a Git submodule in the
elixir-ls folder. Make sure you clone the repo using
git clone --recursive or run
git submodule init && git submodule update after cloning.
elixir-ls as a submodule makes it easy to develop and test code changes for ElixirLS itself. If you want to modify ElixirLS, not just its VS Code client code, you'll want to change the code in the
Here are the basic steps to make changes to ElixirLS locally:
# Make your changes in your editor of choice (fair warning, depending on your changes, ElixirLS may act up since your changes will be immediately reflected)
# Update the ElixirLS version in VSCode
# Make sure to substitute 0.5.0 with the current version before running this command
mix elixir_ls.release -o ~/.vscode-oss/extensions/jakebecker.elixir-ls-0.5.0/elixir-ls-release/
# Restart VSCode
# Now you can test your changes on a project
When you're ready to contribute your changes back to ElixirLS then you need to fork the ElixirLS repo on Github and push any changes you make to the ElixirLS submodule to your fork. An example of how that might look:
# Enter the submodule directory. Now, if you run git commands, they run in the submodule
# Create your feature branch
git checkout -b my_new_branch
# Add your forked elixir-ls repository as a remote
git remote add my_fork firstname.lastname@example.org:<your_github_username>/elixir-ls.git
# Make changes in the elixir-ls folder, commit them, and push to your forked repo
git commit ...
git push my_fork my_new_branch
# Visit https://github.com/elixir-lsp/elixir-ls/compare to start a new Pull Request
Running the tests locally
You should ensure that the tests run locally before submitting a PR, and if relevant add automated tests in the PR.
npm run compile
There is another VS Code extension for Elixir, VSCode Elixir. It's powered by Elixir Sense, another language "smartness" server similar to ElixirLS. Much of this extension's client code (such as syntax highlighting) was copied directly from VSCode Elixir, for which they deserve all the credit.