@ismail-elkorchi/css-parser

Deterministic CSS parsing and selector utilities for automation across Node, Deno, Bun, and modern browsers.

No runtime dependencies: this package ships with zero runtime dependencies.

When To Use

• You need deterministic CSS parse/serialize output.
• You need selector querying without browser-engine side effects.
• You need explicit resource budgets for untrusted stylesheets.

When Not To Use

• You need browser layout/cascade computation.
• You need stylesheet sanitization and policy enforcement in one step.
• You need script or DOM runtime semantics.

Install

npm install @ismail-elkorchi/css-parser

deno add jsr:@ismail-elkorchi/css-parser

Import

import { parse } from "@ismail-elkorchi/css-parser";

import { parse } from "jsr:@ismail-elkorchi/css-parser";

Copy/Paste Examples

Example 1: Parse CSS

import { parse } from "@ismail-elkorchi/css-parser";

const tree = parse(".card { color: red; }");
console.log(tree.kind);

Example 2: Parse streaming input

import { parseStream } from "@ismail-elkorchi/css-parser";

const stream = new ReadableStream({
  start(controller) {
    controller.enqueue(new TextEncoder().encode(".a{display:block}"));
    controller.close();
  }
});

const tree = await parseStream(stream, { budgets: { maxInputBytes: 4096, maxBufferedBytes: 512 } });
console.log(tree.kind);

Example 3: Query selectors

import { compileSelectorList, querySelectorAll } from "@ismail-elkorchi/css-parser";

const selector = compileSelectorList(".card");
console.log(selector.supported, querySelectorAll(selector, { kind: "document", children: [] }).length);

Example 4: Extract render signals

import { extractRenderSignals, parse } from "@ismail-elkorchi/css-parser";

const tree = parse(".card { color: red; }");
console.log(extractRenderSignals(tree).length >= 0);

Run packaged examples:

npm run examples:run

Compatibility

Runtime compatibility matrix:

| Runtime | Status | | --- | --- | | Node.js | Supported | | Deno | Supported | | Bun | Supported | | Browser (evergreen) | Supported |

Security and Safety Notes

Parsing is not sanitization. For untrusted input:

• configure strict budgets,
• handle BudgetExceededError explicitly,
• apply separate policy checks before execution or rendering.

Documentation

• Docs index
• First parse success tutorial
• Options reference