A VS Code extension for just, the command runner.
Status: pre-release. Language support and recipe running are built and tested — syntax
highlighting, semantic tokens, the document outline, folding, CLI detection with a status bar,
and a Run button above every recipe. Completion, hover, diagnostics and the rest of the
product are not yet built. Install the pre-release channel to follow along; stable releases
start with the MVP.
Install
From the Extensions view, search for Justfile Tools and choose Install Pre-Release Version.
The extension is published to the
Visual Studio Marketplace.
It is not on Open VSX yet, so VSCodium and other editors that use that registry cannot install
it from their Extensions view for now.
Or from the command line:
code --install-extension KartikRajput.just-lang --pre-release
What works today
- Syntax highlighting for
justfile, Justfile, .justfile and *.just
- Semantic tokens on top of the grammar, from an error-tolerant parser — half a Justfile still
highlights
- Document outline, with recipes gathered under their
[group]s
- Folding for recipe bodies, multi-line expressions and comment blocks
- Status bar showing the detected
just version, with commands to check the installation and
point the extension at a different executable
- ▶ Run above every recipe, and Run with Arguments… when it has parameters. Runs
just <recipe> as a task in the integrated terminal, asking for required parameters first.
Also Just: Run Recipe in the Command Palette.
Only the last two run just — and both wait for Workspace Trust. Everything else is served by
the in-process parser and works in untrusted workspaces and without just installed.
Design
The full product requirements document is a local working file and is not published. The short
version:
Two tiers, with a hard boundary.
|
Tier 1 — in-process parser |
Tier 2 — just CLI |
| Runs |
Every keystroke |
On demand, trusted workspaces only |
| Provides |
Highlighting, semantic tokens, outline, folding, completion, navigation |
Diagnostics, canonical metadata, formatting |
| Cost |
Sub-millisecond, zero I/O, zero subprocesses |
Subprocess, cached, single-flight |
Two rules follow from that split, and the rest of the design is downstream of them:
- Tier 1 never emits a semantic diagnostic.
just is the only authority on whether a Justfile is valid. A wrong squiggle is worse than no squiggle.
- Tier 2 never runs in an untrusted workspace.
just evaluates backticks and shell() at parse time, so merely reading a Justfile with the CLI executes whatever it contains. See SECURITY.md.
Requirements
- VS Code 1.101.0 or later
just 1.27.0 or later, for the status bar and for the Tier 2 features still to come
Everything Tier 1 provides works without just installed at all, and in untrusted workspaces.
Development
npm ci
just check
just --list shows every command. See CONTRIBUTING.md for the branching,
commit and PR conventions, AGENTS.md for the architectural invariants the codebase
is built around, and RELEASING.md for how a version gets to the Marketplace.
