EXPERIMENTAL

DragonRuby intelligence in your editor

drenv ships a language server for DragonRuby projects. No gems, no Ruby toolchain, no stub repositories — everything is derived from the engine version your project actually uses, offline, including your vendored dependencies.

Requires drenv 0.17.0 or newer — check with drenv --version, upgrade with drenv self-update. On older versions editors report the server crashing on startup.

Completions

The full args.* tree, Geometry and Easing, mruby core methods, and your project's own definitions — vendored libraries included. One-hop typing means enemies = [] makes enemies. complete like an Array, and @anim = Animation.new completes your class's methods, inherited ones too.

mygame/app/main.rb

# the server knows enemies is an Array

enemies = []

enemies.fi

ƒeachmruby core

ƒfilter_mapArray — DragonRuby 7.13

ƒmap_2dArray — DragonRuby 7.13

ƒproductArray — DragonRuby 7.13

ƒrejectmruby core

Docs on hover

The same content docs.dragonruby.org serves, matched to the engine version your project actually uses. Your own comment blocks render too — YARD tags become rich markdown with clickable constant links.

mygame/app/main.rb

Geometry.distance — DragonRuby 7.13

Returns the distance between two points.

distance(point_one, point_two)

dist = Geometry.distance({ x: 0, y: 0 }, player)

Signature help

Positional and keyword parameters with the active argument highlighted as you type — including DragonRuby's paren-less call style. Signatures come from the engine's own source.

mygame/app/main.rb

rotate_point(point, angle, around = nil)

angle — degrees to rotate point around

Geometry.rotate_point({ x: 0, y: 0 }, 90

Diagnostics

Unknown engine methods, wrong argument counts, unknown or missing keywords, duck-shape checks, and performance hints linked to the engine's shipped guide. Warnings only fire when the server fully owns the receiver — a squiggle means something is actually wrong.

mygame/app/main.rb

Geometry.nope(args)

Geometry.rect_navigate rec: {}

⚠ rec: is not a keyword of Geometry.rect_navigate — accepted: rect:, rects:

drenv (DragonRuby 7.13)

Navigation

Go to definition and references across mygame/ and vendor/, resolved the way Ruby dispatches: own class, superclass chain, then same file. Locals stay method-scoped, and if a library you're developing is vendored into the same workspace, results point at the editable source — not the vendored copy.

mygame/app/scenes/hero.rb

@hero_anim.play(:walk)

References · 3

lib/conjuration/animation.rb:233def play(name)

app/scenes/hero.rb:12@hero_anim.play(:walk)

app/scenes/hero.rb:27@hero_anim.play(:idle)

drenv.toml

Validation and key completion for the dependency manifest, from the same schema the CLI uses — typos and unknown sources get flagged before you ever run drenv bundle.

mygame/drenv.toml

[package]

name = "my_game"

entrypint = "app/game.rb"

⚠ unknown key entrypint in [package] — known: root, entrypoint, include

drenv

Editor setup

Install drenv 0.17.0 or newer first, so drenv is on your PATH. Not activating? Run drenv lsp doctor in your project.

VS Code

Install drenv from the Marketplace — search drenv in the Extensions panel, or run code --install-extension nitemaeric.drenv-lsp. Open a Ruby file in a DragonRuby project and it activates.

Emacs

With built-in eglot (Emacs 29+), register the server for Ruby:

(with-eval-after-load 'eglot
  (add-to-list 'eglot-server-programs
               '((ruby-mode ruby-ts-mode) . ("drenv" "lsp"))))

Then M-x eglot in a DragonRuby project. Full eglot and lsp-mode setup in editors/emacs.

Zed

Coming to the Zed extension registry (review pending). Until then, clone the repo and run zed: install dev extension on editors/zed/. Safe to enable globally — the server stays dormant outside DragonRuby projects.

Any LSP editor

Point your client at command drenv with args ["lsp"] for Ruby files. The conventional --stdio flag is accepted. A Neovim config lives in editors/nvim.

Every rule, by feature, on the rule reference page. Project detection and troubleshooting in the LSP docs.