# Firebase Cpp Formatter

> Formatting workflow for C++ and Objective-C code in the Firebase C++ SDK. Use when modifying source code and ensuring compliance with the repository's clang-format rules.

- Skill: `firebase/firebase-cpp-formatter` (Agent Skill)
- Install (CLI): `npx skillmds@latest add firebase/firebase-cpp-formatter`
- Raw SKILL.md: https://api.skillmd.com/api/skills/firebase/firebase-cpp-formatter/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Productivity
- Author: firebase (https://skillmd.com/u/firebase)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/firebase/firebase-cpp-formatter

---


# Code Formatting for Firebase C++ SDK

This skill provides instructions on how to properly format C++ and Objective-C
code before creating a pull request or committing changes in the
`firebase-cpp-sdk` repository. The primary tool is `scripts/format_code.py`.

## Prerequisites

Before running the formatting script, ensure that your Python environment is set up with all required dependencies:

- **Python Dependencies**: Run `pip install -r scripts/gha/python_requirements.txt` to install the required libraries (such as `attrs`, `absl-py`, etc.).

## Workflows

### 1. Formatting Specific Changed Files (Git Diff)

If you have made code changes locally in a git branch, the easiest way to ensure
all your changes are formatted properly is to use the `-git_diff` argument. This
automatically detects which files have changed compared to `main` and formats
them.

```bash
python3 scripts/format_code.py -git_diff
```

_Tip:_ You can also append `-verbose` for extensive logging about formatting
changes.

### 2. Formatting a Specific Directory

If you are working on a feature within a particular Firebase SDK (e.g.,
`database`), you can recursively format that entire directory:

```bash
python3 scripts/format_code.py -d database -r
```

To target multiple directories (e.g., both `database` and `app`):

```bash
python3 scripts/format_code.py -d database -d app -r
```

### 3. Formatting Specific Files

If you are pressed for time and only want to format specific files rather than
analyzing whole directories, use the `-f` flag:

```bash
python3 scripts/format_code.py -f path/to/file1.cc -f path/to/file2.h
```

### 4. Dry Run (Check without Formatting)

If you only want to detect the number of files that _need_ formatting without
actually modifying them, append the `--noformat_file` flag:

```bash
python3 scripts/format_code.py -git_diff --noformat_file
```