typescript.el

typescript.el is a major-mode for editing Typescript-files in GNU Emacs.

typescript.el is a self-contained, lightweight and minimalist major-mode focused on providing basic font-lock/syntax-highlighting and indentation for Typescript syntax, without any external dependencies.

Output from tsc and tslint is also handled seamlessly through compilation-mode.

A short note on development HALT

As the both the JavaScript and TypeScript languages have evolved to become ever more complex, so has the Elisp codebase for typescript-mode trying to correctly handle them.

We''ve been at the point for quite some time where it has become increasingly obvious that the current code-base simply cannot continue growing. It will be slow. It will be complex. It will be buggy. It will be head-ache inducing to wrap our heads around it, and ... I guess we're already there.

Apart from occasional PRs getting merged, the current typescript-mode code isn't being developed because almost nobody wants to work code of this complexity.

Essentially all major development of typescript-mode has come to a halt.

Seeing the forest for trees

Lots of Emacs major-modes are facing the same problem. I'm sure there's similar issues for other editors too.

This means lots of developers are working on solving this problem once and for all, and what they've decided on is relying on a standardized set of external parsers using the tree-sitter library.

New major modes are being developed as we speak to support TypeScript (and other languages) within Emacs based on Emacs' upcoming native tree-sitter support.

The code will be much faster, it will be simpler to work with and everyone should be happy. Well almost. Since tree-sitter support relies on a new major feature being added to core Emacs, it also means that these new major modes won't be backward compatible with older Emacs-versions.

For that reason we are not replacing this major mode with the new and improved one, but keeping it around to make sure older Emacs-versions does at least have an option for working with Typescript, even though it may not be optimal or track recent changes to the TypeScript-language.

But once new Emacs ships with tree-sitter support, you are adviced to upgrade to the newer modes for better TypeScript-support, rather than keeping this old version around.

Good news!

Emacs 29 will ship with tree-sitter support, and it will actually have in-tree support for TypeScript! So now you can just use the provided typescript-ts-mode and get the fresh tree-sitter powered functionalities for free. Yes, that means both tsx and regular types will actually work. Development will continue in emacs core, rather than this repo. We hope you'll like the new experience.

Installation

typescript.el can be installed from source directly using your favourite approach or framework, or from MELPA and MELPA Stable as a package.

To install typescript.el simply type M-x package-install<RET>typescript-mode<RET>.

Customization

To customize typescript.el just type the following: M-x customize-group<RET>typescript<RET>.

You can add any other customization you like to typescript-mode-hook in your init.el file. typescript.el also handles prog-mode-hook on versions of Emacs which supports it.

Support for Compilation Mode

This mode automatically adds support for compilation-mode so that if you run M-x compile<ret>tsc<ret> the error messages are correctly parsed.

However, the error messages produced by tsc when its pretty flag is turned on include ANSI color escapes, which by default compilation-mode does not interpret. In order to get the escapes parsed, you can use:

(require 'ansi-color)
(defun colorize-compilation-buffer ()
  (ansi-color-apply-on-region compilation-filter-start (point-max)))
(add-hook 'compilation-filter-hook 'colorize-compilation-buffer)

Or, if you prefer, you can configure tsc with the pretty flag set to false: tsc --pretty false. However, doing this does more than just turning off the colors. It also causes tsc to produce less elaborate error messages.

Contributing

To run the tests you can run make test.

If you prefer, you may run the tests via the provided Dockerfile.

docker build -t typescript-mode .
docker run --rm -v $(pwd):/typescript-mode typescript-mode

Other Typescript-packages of interest

While typescript.el may not provide a full kitchen-sink, the good news is that there's other packages which do!

More advanced features can be provided by using these additional packages:

• lsp-mode - A standards-based code-completion and refactoring backend, based on the Language Server Protocol (LSP).

• tide - TypeScript Interactive Development Environment for Emacs

• ts-comint - a Typescript REPL in Emacs.

Initializing these with typescript.el will then become a matter of creating your own typescript-mode-hook in your init.el file.