42 Next Header

A VS Code extension that inserts and maintains the standard 42 school file header. The Updated timestamp and filename are kept in sync automatically on every save.

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   vscode-42next-header                               :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: marvin <marvin@student.42madrid.com>       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2019/09/26 10:10:10 by marvin            #+#    #+#             */
/*   Updated: 2026/05/17 21:42:42 by marvin           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

About

42 Next Header is a modern rewrite and continuation of the original vscode-42header extension. It preserves the same concept but is rebuilt with TypeScript strict mode, zero runtime dependencies and tests.

Features

One shortcut inserts or updates the header in any supported language.
Auto-sync on save: the Updated field and filename refresh automatically when you save a file that already has a header.
Formatter-safe: works with rustfmt, black, ruff, clang-format, and other formatters that might rewrite comment syntax.
Custom delimiters: override the default comment style for any language via settings.
Zero runtime dependencies: lightweight, fast, and offline.
flake8-compatible: Python headers use line comments (# ) without trailing #, so flake8 and ruff won't flag them.
Shebang-aware: when a file starts with #!/usr/bin/env python3 (or any #! line), the header is placed right after it. Updates on save preserve the shebang position.

Installation

From the VS Code Marketplace

Open VS Code, go to Extensions (Cmd+Shift+X / Ctrl+Shift+X), search for "42 Next Header", and click Install.

From a .vsix file

If you have a .vsix file:

Open VS Code
Go to Extensions → ··· (top-right menu) → Install from VSIX…
Select the .vsix file

To uninstall, find "42 Next Header" in the Extensions panel and click Uninstall.

Usage

Action	macOS	Linux / Windows
Insert or update header	`Cmd+Alt+H`	`Ctrl+Alt+H`

The header is inserted at the top of the active file. If a header already exists, it is replaced in-place so the Updated field and filename stay current.

The Updated field and filename are refreshed automatically every time you save a file that already has a header. You do not need to press the shortcut again after the first insertion.

Configuration

All settings live under the 42header namespace. You can set them globally in your VS Code User Settings or per-project in .vscode/settings.json.

Basic settings

{
  "42header.username": "pruiz-ca",
  "42header.email": "pruiz-ca@student.42.fr"
}

Setting	Type	Default	Description
`42header.username`	`string`	`$USER` env variable	Username shown in the header
`42header.email`	`string`	`<username>@student.42.fr`	Email shown in the header
`42header.languageDelimiters`	`object`	`{}`	Override comment delimiters per language

Custom delimiters

You can override the comment delimiters for any language. Each value is a ["left", "right"] pair of equal-length strings. The extension warns you at startup if a value is malformed.

{
  "42header.languageDelimiters": {
    "zig": ["// ", " //"],
    "ada": ["-- ", " --"]
  }
}

Important: The extension validates delimiter overrides on activation and whenever the setting changes. Invalid entries (non-arrays, wrong length, non-string elements, or empty left delimiters) are ignored and a warning is shown.

Supported languages

Built-in support for 37 languages:

C, C++, CoffeeScript, CSS, Dockerfile, F#, Go, Groovy, Haskell, INI, Jade, Java, JavaScript, JSX, LaTeX, Less, Lua, Makefile, Objective-C, OCaml, Perl, PHP, Plaintext, PowerShell, Python, R, Ruby, Rust, SCSS, Shell, SQL, Swift, TypeScript, TSX, XSL, YAML

Special handling:

Rust uses // line comments to stay compatible with rustfmt.
Python uses # line comments (no trailing #) to stay compatible with black, ruff, and flake8.
Shebangs: headers are placed after #! lines when present. The extension detects and updates them in-place on save.
Other languages use block comments (/* ... */, (* ... *), etc.) where available.

Troubleshooting

"No comment delimiter for language 'xyz'"

The language you are using does not have a built-in delimiter. Add one via 42header.languageDelimiters in your settings.

Header is not updated on save

Make sure the file already has a 42 header. The auto-update only triggers for files that contain a valid header at the top. If the header was inserted with a different extension or manually, it may not be recognized.

Formatter removes the header

Some aggressive formatters may rewrite comment syntax. The extension handles this automatically by re-applying the correct delimiter after the formatter runs. If you still see issues, try using line-comment delimiters for that language (e.g. // instead of /* */).

Developer Guide

Want to add a language, fix a bug, or extend functionality? This section is for you.

Project structure

src/
├── delimiters.ts    # Language ID → [left, right] delimiter mappings
├── extension.ts     # VS Code activation, commands, save watchers
├── header.ts        # Header template, field extraction, rendering
├── template.ts      # ASCII template, field locate/set/get helpers
└── test/
    ├── delimiters.test.ts   # Delimiter validation tests
    └── header.test.ts      # Header render/extract/round-trip tests

Adding a language

Open src/delimiters.ts.
Add a new entry to defaultDelimiters:
```
zig: ['// ', ' //'],
```
The key must be the VS Code languageId shown in the status bar when you open a file of that type.
The left and right strings must be the same length so the 80-character line width is preserved.
Add a round-trip test in src/test/header.test.ts (the 'all delimiters produce 80-char lines' test covers it automatically once the entry exists).
Run pnpm typecheck && pnpm test to verify.

Extending functionality

Adding a new command

vscode.commands.registerCommand('42header.myCommand', myCommandHandler)

Adding a new setting

Add the property to contributes.configuration.properties in package.json.
Read it in src/extension.ts via vscode.workspace.getConfiguration('42header').get('mySetting').
Add tests in src/test/delimiters.test.ts or src/test/header.test.ts.

Changing the header template

The template lives in src/template.ts as the TEMPLATE constant. It uses $PLACEHOLDER____ markers where the underscores act as padding to ensure exact 80-character line widths. If you modify the template:

Update HEADER_LINE_COUNT (it is derived automatically from TEMPLATE).
Ensure all non-blank lines are exactly 80 characters after delimiters are applied.
Run tests: the 'every non-blank line is exactly 80 characters' test will catch any width violations.

Building and testing

# Install dependencies and activate git hooks
pnpm install

# Watch-mode TypeScript compile
pnpm compile

# Run tests once
pnpm test

# Run tests in watch mode
pnpm test:watch

# Full TypeScript type check
pnpm typecheck

# Launch in VS Code Extension Development Host
# Press F5 or open Run panel → Launch Extension

Packaging locally

pnpm add -g @vscode/vsce
vsce package --allow-missing-repository

This produces 42next-header-<version>.vsix in the project root.

Contributing

See CONTRIBUTING.md in the repository root for pull request guidelines, CI requirements, and hook setup.

License

MIT License