quark-formatter

Prettier-style formatting for Quark sheets — one call, one canonical style, nothing to configure.

import { format } from "@excom/quark-formatter";

format(`provider-fetch[is-success]{$todos:prop("provision").body;ul{content:iterate($todos)}}`);
// provider-fetch[is-success] {
//   $todos: prop("provision").body;
//   ul {
//     content: iterate($todos);
//   }
// }

Features

• One style Two-space indent, 80-column wrapping, one selector per line, single blank lines between groups
• Safe Invalid Quark throws instead of rewriting; comments stay where they were written; formatting is idempotent
• Editor / CLI ready Powers Format Document in the Nucleus & Quark extension and the monorepo format script
• Self-contained Parser bundled in; runs in Node, bundlers and browsers

Installation

Usage

format(source, options?) returns the formatted sheet as a string. The only option is indent (default two spaces).

import { format } from "@excom/quark-formatter";

const pretty = format(source, { indent: "\t" });

Invalid input throws QuarkParseError (from @excom/quark-parser) with the line and column, so callers leave the original file untouched:

try {
  fs.writeFileSync(file, format(fs.readFileSync(file, "utf8")));
} catch (error) {
  console.error(`${file}: ${error.message}`);
}

What gets normalized

• Whitespace, indentation and blank lines (at most one preserved between statements)
• Selector lists: one per line at rule heads, , -joined inside :not() / :is()
• Operator spacing, with only the parentheses the expression needs: ($a or $b) and $c
• Accessors and call chains print compactly: $todo.title, $row["id"], closest("li").getAttribute("id")
• Comments (/* … */ only) keep their position, including trailing same-line comments
• Lines wrap at 80 columns the way prettier wraps CSS: maps, call arguments, if() arms, @on / @dispatch / @command / @view-transition options and @delay durations that overflow break one item per line, operator chains wrap like text, a comma list of multi-word values breaks one value per line

content: formatPrice(
  pricing.total($items, $tax-rate) - pricing.discount($items, $coupon-code),
  $currency
);
data-mode: if(
  event.target.name == "data-mode": event.target.value;
  else: preserve
);

Strings, selectors and interpolations never wrap, so a long content: "…#{…}…" stays on one line. Listener at-rules print as @on input, change (target: "[name]", debounce: 300) { — the event list as written, the options group like a map — and @dispatch / @command statements the same way; @view-transition (types: "todo-change") { prints its options like @on's and always opens a block, as does @scope {.

Quark is a derivative of CSS with at-rules of its own, and the formatter prints those — @use, @scope, @on, @dispatch, @command, @view-transition, @delay, @warn, @debug, @error — and nothing else. A sheet the parser rejects, such as one holding @media or !important, throws rather than being reformatted.

In the editor

Install the Nucleus & Quark Syntax Highlighter to format .quark files with Format Document and inline <quark-sheet> blocks with a command.

Full documentation: https://nucleus.excom.dev/packages/quark-formatter