CI のビルド時に patch を適用する際の注意点 ref: http://qiita.com/jimbo/items/1643523195b03f53e860

file0.txt

# 1回目
$ patch --batch -p0 -i xxx.patch
patching file node_modules/foo/bar/xxx

# 2回目
$ patch --batch -p0 -i xxx.patch
patching file node_modules/foo/bar/xxx
Reversed (or previously applied) patch detected!  Assuming -R. # 元に戻ってしまう

file1.txt

$ patch --batch -N -p0 -i xxx.patch
patching file node_modules/foo/bar/xxx
Reversed (or previously applied) patch detected!  Skipping patch.
1 out of 1 hunk ignored -- saving rejects to file node_modules/foo/bar/xxx.rej

patch-xxx.sh

#!/bin/bash

PATCH_CMD="patch --batch --silent -p0 -N -i xxx.patch"

if ${PATCH_CMD} --dry-run; then
  ${PATCH_CMD}
fi