@cldmv/prettier-plugin-jsonv

A Prettier plugin for formatting JSONV files.

✨ What's New

Latest: v1.2.2 (November 2026)

• Tooling release, no plugin changes — the vitest config now uses devCondition() from @cldmv/configs, so tests really run against src/ through the prettier-plugin-jsonv-dev export condition, and the type scripts are split into types:check and types:build (#91, #93). Formatting is unchanged.
• View full v1.2.2 Changelog

Recent Releases

• v1.2.1 (November 2026) — engines.node back to >=18.0.0; the 22.22.0 development floor moves to devEngines (#88) (Changelog)
• v1.2.0 (November 2026) — CommonJS entry, tsup build and a prettier-plugin-jsonv-dev export condition; engines.node raised to >=22.22.0; formatting unchanged (#84, #85) (Changelog)
• v1.1.4 (October 2026) — dev tooling on @cldmv/fix-headers 2.2.0 and @cldmv/configs 1.2.4; no file was restamped and no runtime change (#51, #54) (Changelog)
• v1.1.3 (October 2026) — the CI ✅ Required PR Check mirror job runs on every path instead of being skipped on in-repo PRs (#49) (Changelog)

📚 For complete version history, see docs/changelog/ and the GitHub Releases.

Features

• Formats .jsonv files using the @cldmv/jsonv parser
• Supports all ES2015-2025 features (JSON5, binary/octal literals, BigInt, numeric separators, etc.)
• Configurable year-based feature detection
• Proper handling of comments and whitespace
• Integrates with Prettier's configuration system

Installation

npm install --save-dev @cldmv/prettier-plugin-jsonv prettier @cldmv/jsonv

Usage

The plugin needs Node.js 18.0.0 or later and Prettier 3. It ships an ES module entry and a CommonJS entry, so it loads from either kind of Prettier config; require() needs Node.js ^20.19.0 or >=22.13.0.

Developing this package needs Node.js 22.22.0 or later (devEngines).

Using .prettierrc.mjs or prettier.config.mjs:

import jsonv from "@cldmv/prettier-plugin-jsonv";

export default {
    plugins: [jsonv],
    overrides: [
        {
            files: "*.jsonv",
            options: {
                jsonvYear: 2025,
                strictBigInt: false
            }
        }
    ]
};

Using .prettierrc.cjs or prettier.config.cjs:

module.exports = {
    plugins: [require("@cldmv/prettier-plugin-jsonv")],
    overrides: [
        {
            files: "*.jsonv",
            options: {
                jsonvYear: 2025,
                strictBigInt: false
            }
        }
    ]
};

require("@cldmv/prettier-plugin-jsonv") returns the plugin object itself. In a JSON .prettierrc, list the plugin by name instead: "plugins": ["@cldmv/prettier-plugin-jsonv"].

Configuration Options

Trailing commas

The plugin honours Prettier's trailingComma option the way Prettier's JavaScript printer does for object and array literals:

• "all" (Prettier's default) and "es5" put a comma after the last entry of every object or array that breaks across lines. Non-empty objects and arrays are always printed one entry per line, so only empty ones ({ }, []) are printed on a single line, and they never get a comma.
• "none" never adds one.

Trailing commas already in the source are not kept as written: the option normalizes them, adding or removing the comma after the last entry. Every jsonv year (2011-2025) allows trailing commas, so the comma never makes a document invalid, and it never changes the parsed value. Comments next to the last entry stay in place: a: 1, // note keeps the comment after the comma, a: 1 /* note */, keeps it before.

Development

The published package contains only the built dist/ (dist/index.mjs, and dist/index.cjs for require()) plus the generated types/. In a checkout, the prettier-plugin-jsonv-dev export condition points the package at src/ instead:

Set it once per shell with export NODE_OPTIONS=--conditions=prettier-plugin-jsonv-dev. npm test runs the Vitest suite against src/ with the condition, then builds and checks the CommonJS entry in dist/ with node --test.

License

Apache-2.0 © Shinrai / CLDMV