linting

name	linting
description	Code formatting and linting context for the Megahub project. Use when writing or reviewing code in C++ or JavaScript, or when running format/lint checks. Describes tool commands, style conventions, and when to apply them.

Linting & Formatting — Megahub

Tools

Layer	Tool	Config file	Purpose
C++	clang-format	/.clang-format	Code formatting
C++	cppcheck	— (run manually)	Static analysis
JS/CSS	Prettier	/frontend/prettier.config.js	Code formatting
JS	ESLint v9	/frontend/eslint.config.js	Bug detection
Pre-commit	lefthook	/lefthook.yml	Runs all checks on staged files

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Running Tools

JavaScript (run from frontend/)

npm run lint           # ESLint check (errors and warnings)
npm run lint:fix       # ESLint auto-fix where possible
npm run format         # Prettier — write formatted output
npm run format:check   # Prettier — check only (no writes)

C++ (run from project root)

# Format a single file in-place
clang-format -i lib/megahub/src/megahub.cpp

# Check all lib and src files without modifying
find lib src -name "*.cpp" -o -name "*.h" | xargs clang-format --dry-run --Werror

# Static analysis
cppcheck --enable=warning,performance,portability \
         --suppress=missingInclude \
         --suppress=unusedFunction \
         --suppress=ctuOneDefinitionRuleViolation \
         --inline-suppr \
         --error-exitcode=1 \
         --quiet \
         lib/btremote lib/commands lib/configuration lib/hubwebserver \
         lib/i2csync lib/imu lib/inputdevices lib/logging lib/lpfuart \
         lib/megahub lib/portstatus lib/statusmonitor \
         src/

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When to Apply

• After writing any JS code: run npm run format then npm run lint from frontend/
• After writing any C++ code: run clang-format -i on the modified files
• The pre-commit hook runs automatically on staged files if lefthook is installed

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Pre-commit Hook Setup (one-time)

brew install lefthook   # macOS
lefthook install        # registers the git hooks

After this, every git commit automatically checks:

• C++ staged files → clang-format (fails if unformatted)
• JS staged files → ESLint (fails on errors)
• JS/CSS staged files → Prettier (fails if unformatted)