Manual pre-commit hook in a monorepo

gistfile1.txt

#!/bin/bash

# avoid pre-commit hooks when fixing conflicts/merging
git rev-parse -q --verify MERGE_HEAD && exit 0

# list all staged JS and TS files
js_ts_files=$(git diff --diff-filter=d --name-only --cached | grep -E '\.(js|jsx|ts|tsx)$')


#############
## LINTING ##
#############
for file in $js_ts_files; do

  ## BACKEND PROJECT ##

  if [[ $file =~ ^"src" ]]; then
      # changes have been made to `backend` project's `src`, check it
      npx eslint --fix "$file"
      linting_result=$?

      git add "$file"

      if [ $linting_result -ne 0 ]; then
        exit 1
      else
        echo "Linted ${file}"
      fi
  fi

  if [[ $file =~ ^"stacks" ]]; then
      # changes have been made to `backend` project's `stacks`, check it
      npx eslint --fix "$file"
      linting_result=$?

      git add "$file"

      if [ $linting_result -ne 0 ]; then
        exit 1
      else
        echo "Linted ${file}"
      fi
    fi

  ## FRONTEND PROJECT ##

  if [[ $file =~ ^"frontend" ]]; then
    # changes have been made to `frontend` project, check it
    cd frontend || exit

    # remove `frontend/` part from filename for ESLint to see the file
    normalized="${file//frontend\//}"
    npx eslint --fix "$normalized"
    linting_result=$?

    git add "$normalized"

    if [ $linting_result -ne 0 ]; then
      exit 1
    else
      echo "Linted ${file}"
    fi

    cd ..
  fi
done


#############
## TESTING ##
#############

set -e

should_run_backend_tests=false
should_run_frontend_tests=false
should_run_analog_cli_tests=false

for file in $js_ts_files; do
  # check what the file path starts with
  if [[ $file =~ ^"src" ]]; then # backend folder
    should_run_backend_tests=true
  fi

  if [[ $file =~ ^"stacks" ]]; then # backend folder
    should_run_backend_tests=true
  fi

  if [[ $file =~ ^"frontend" ]]; then
    should_run_frontend_tests=true
  fi

  if [[ $file =~ ^"analog-cli" ]]; then
    should_run_analog_cli_tests=true
  fi
done

if [[ $should_run_backend_tests == true ]]; then
  npm run test
fi

if [[ $should_run_frontend_tests == true ]]; then
  cd frontend || exit
  npm run test
  cd ..
fi

if [[ $should_run_analog_cli_tests == true ]]; then
  cd analog-cli || exit
  npm run test
  cd ..
fi