Badness

A language server, formatter, and linter for LaTeX.

Quick start

1. Install the Badness extension.
2. Open a LaTeX (.tex) file.
3. The extension starts badness lsp automatically.

By default, the extension uses a badness binary that ships inside the extension itself, so the language server starts on first activation even on restricted or offline networks.

Features

• Starts badness lsp automatically when you open supported documents.
• Formats documents using Badness's deterministic, rule-based formatter.
• Surfaces Badness diagnostics in the editor.
• Works for LaTeX (.tex) and related TeX/BibTeX files.

Commands

• Badness: Restart Server: stops and restarts the Badness language server (re-reads settings and re-resolves the binary). Useful if the LSP gets wedged or after changing settings such as badness.version or badness.executablePath.
• Badness: Forward Search: opens your PDF viewer at the cursor's position. Requires badness.forwardSearch.executable and badness.forwardSearch.args, plus a PDF built with SyncTeX enabled (latexmk -pdf -synctex=1). Badness never builds the document itself.

Binary installation

By default, the extension uses a badness binary that ships inside the extension (one platform-specific VSIX per OS/architecture). No download, no GitHub round-trip, and the language server starts on first activation even on restricted or offline networks. Behavior is controlled by badness.executableStrategy:

• bundled (default): use the binary that ships inside the extension. If you're on a platform without a platform-specific build (or you've installed the universal VSIX), the extension falls back to downloading a matching binary from GitHub releases.
• environment: look for badness on the system PATH.
• path: use the binary at badness.executablePath.

If you set badness.version or badness.releaseTag explicitly, the bundled binary is skipped and the requested version is downloaded from GitHub. When badness.version is latest, the extension automatically selects the most recent stable release that contains a matching platform asset.

Common setup examples

Use a local binary at a fixed path:

{
  "badness.executableStrategy": "path",
  "badness.executablePath": "/usr/local/bin/badness"
}

Use whatever badness is on your PATH:

{
  "badness.executableStrategy": "environment"
}

Pin to a specific release:

{
  "badness.version": "0.2.0",
  "badness.githubRepo": "jolars/badness"
}

Use badness.releaseTag only if you need an exact tag override:

{
  "badness.releaseTag": "v0.2.0"
}

Requirements and troubleshooting

• NixOS: the bundled binary won't run because of the dynamic loader path. Set badness.executableStrategy to path (with badness.executablePath) or environment if badness is on your PATH.
• Offline, restricted networks, or proxies: the bundled-binary default works without network access. Only the explicit-version download paths (badness.version/badness.releaseTag) require GitHub connectivity.
• If a download fall-through fails, the extension shows a warning and falls back to looking up badness on the system PATH.

Choosing which features to use

Badness bundles a formatter, a linter, and language features (hover, completion, navigation, and so on) behind one language server. Each can be turned off independently, so you can use just the parts you want:

• badness.formatting.enable (default true): use Badness as a formatter. Set to false to let another extension own LaTeX formatting without disabling Badness.
• badness.diagnostics.enable (default true): show Badness diagnostics (the linter). Set to false to suppress all squiggles, including the syntax/parse errors that a badness.toml [lint] selection cannot silence.
• badness.languageFeatures.enable (default true): hover, completion, signature help, go-to-definition, references, symbols, rename, code actions, folding, selection ranges, and document links.

For a formatter-only setup (the common "I just want the formatter" case):

{
  "badness.diagnostics.enable": false,
  "badness.languageFeatures.enable": false
}

The language server keeps running either way—these are client-side gates—so formatting stays available and the toggles take effect without reinstalling anything.

Settings

Badness registers itself as the default formatter for [latex] files.

• badness.formatting.enable: use Badness as a formatter (default true).
• badness.diagnostics.enable: show Badness diagnostics/the linter (default true).
• badness.languageFeatures.enable: enable hover, completion, navigation, and the other language features (default true).
• badness.executableStrategy: how to locate the badness binary—bundled (default), environment, or path.
• badness.executablePath: path to the binary, used only when executableStrategy is path.
• badness.version: version to install (default: "latest")
• badness.releaseTag: advanced exact tag override (takes precedence if explicitly set)
• badness.githubRepo: GitHub repo for downloads (default: "jolars/badness")
• badness.serverArgs: extra args after badness lsp
• badness.serverEnv: extra environment variables
• badness.extraPath: extra PATH entries prepended for the language server process
• badness.logLevel: log level for the language server, mapped to RUST_LOG (off, error, warn, info, debug, trace; unset by default). badness.serverEnv.RUST_LOG overrides this if both are set.
• badness.trace.server: LSP trace level (off, messages, verbose)
• badness.lineWidth, badness.indentWidth: formatter width fallbacks. A discovered badness.toml always wins; absent one, your editor's tab size wins over indentWidth.
• badness.texmf: how the server finds your installed TeX tree (enabled, roots, useKpsewhich), for document links, package hover, go-to-definition, and installed-set completion. Never affects formatting or linting.
• badness.forwardSearch.executable: the PDF viewer for Badness: Forward Search. A program name, not a command line — it is spawned directly, so flags belong in args.
• badness.forwardSearch.args: the viewer's arguments, where %f is the file the cursor is in, %p the root document's PDF, and %l the line number counting from 1. For zathura: ["--synctex-forward", "%l:1:%f", "%p"].

These four are read once, when the server starts, so changing them restarts it automatically. Where the PDF lands is project data and belongs in badness.toml's [build] section (pdf-dir, pdf-filename, root).

Security and trust

When badness.executableStrategy is bundled (the default), the extension prefers the binary that shipped inside the VSIX. If no bundled binary is available, or badness.version/badness.releaseTag is set explicitly, it downloads from GitHub releases configured by badness.githubRepo (default jolars/badness).