Lapce Copilot

This is an unofficial Copilot plugin for Lapce.
IMPORTANT NOTE: This plugin currently requires nightly Lapce, as the inline completions feature is not yet on stable.

Installation

Requires: NodeJS 16+ It will try to find the node binary in your path, but you can also change the setting to point to the binary.

Open Lapce
Go to the plugins panel
Find 'Copilot (Unofficial)'
Click install

This will immediately open a browser window to the Github login page with a notification containing a code. Enter that code into the website to authorize Copilot. You shouldn't need to do this again.

Development

Building:
Requires: rustup target add wasm32-wasi

cargo build --release

The plugin file will be located in target/wasm32-wasi/release/lapce-copilot.wasm
This can be copied to a folder along with a couple other files:

minusgix.lapce-copilot/
  - dist/
  - volt.toml
  - lapce-copilot.wasm

Updating

If Copilot ends up out of date, then it can be updated by copying the dist/ folder from the copilot.vim repo. That repo contains an agent.js which this plugin starts as the actual core copilot.

Impl Details

This plugin currently:

Looks for node
- And checks if the node version is good
Tells Lapce to spawn a new Language Server using roughly [node, agent.js]
- I'm not sure if it is waiting for copilot to send the initialize response back to Lapce, possibly it should
The plugin sends to the newly spawned Copilot LSP information about the editor + plugin
- names and versions, but also some configuration
The plugin asks Copilot if we are signed in
- If we are not, then it does a few more requests to try signing in
The Copilot LSP currently uses a nonstandard getCompletions/getCompletionsCycling request.
- I didn't try to implement this in Lapce because it is from a single plugin, and is also of dubious origin since Github doesn't document their own API.
- Lapce implements the 3.18 (upcoming) LSP command textDocument/inlineCompletion which serves a similar purpose.
- So the plugin tells Lapce that it supports Inline Completions, and maps those to the Copilot LSP requests and back.
- We also have to listen for onChange/onOpen events, because Copilot wants the version of the file to be sent with the request but textDocument/inlineCompletion does not include that.

Once 3.18 is standardized, if Copilot's agent.js implements inlineCompletion then that special-handling can be removed from this extension.

License