git addgrep: stage all diff hunks that match a given regexp

git-addgrep

#!/bin/bash -e

# Renamed a file or method? Use this to add all files matching that regex pattern.

# Assumes this file lives in $ROOT/bin, so we need to hop up a level (the `/..` bit)
ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")"/.. >/dev/null 2>&1 && pwd)"
cd "$ROOT"

# Ignore calls to `git add` that have no filenames:
git config advice.addEmptyPathspec false

if [ "${HUNKS:-1}" == 1 ]; then
  echo "(staging matching hunks)"
  git diff -U0 | grepdiff -E "$*" --output-matching=hunk | git apply --cached --unidiff-zero
else
  echo "(staging matching files)"
  # -S Looks for differences that change the number of occurrences of the specified
  # shellcheck disable=SC2046
  git add --ignore-errors -- $(git diff -S"$*" --name-only)
  # -G Looks for differences whose patch text contains added/removed lines that match <regex>.
  # shellcheck disable=SC2046
  git add --ignore-errors -- $(git diff -G"$*" --name-only)
fi