Create magento 2 custom patch via composer

magento-2-custom-patch-via-composer

# Patcher

composer require cweagans/composer-patches

git add -f ./vendor/magento/module-catalog/Model/ResourceModel/Product.php

# Edit file in vendor e.g. ./vendor/magento/module-catalog/Model/ResourceModel/Product.php

mkdir ./patches         
mkdir ./patches/composer

git diff ./vendor/magento/module-catalog/Model/ResourceModel/Product.php > ./patches/composer/skeleton.patch

git reset HEAD ./vendor/magento/module-catalog/Model/ResourceModel/Product.php

# Undo change on file e.g. ./vendor/magento/module-catalog/Model/ResourceModel/Product.php

# composer json

```
    "extra": {
        "magento-force": "override",
        "composer-exit-on-patch-failure": true,
        "patches": {
            "magento/module-catalog": {
                "Xigen import fix": "patches/composer/skeleton.patch"
            }
        }
    }
```

composer install

```
composer install                                                                                          
Gathering patches for root package.
Removing package magento/module-catalog so that it can be re-installed and re-patched.
  - Removing magento/module-catalog (103.0.5-p2)
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. It is recommended that you run `composer update` or `composer update <package name>`.
Package operations: 1 install, 0 updates, 0 removals
Gathering patches for root package.
Gathering patches for dependencies. This might take a minute.
  - Installing magento/module-catalog (103.0.5-p2): Loading from cache
  - Applying patches for magento/module-catalog
    patches/composer/skeleton.patch (Xigen import fix)
```

Check file



## To patch multiple files

 - Create branch
 - Add multipe core files
 - Commit to branch
 - Patch files
 - Commit to branch
 - git diff [core hash] [hash with updates] > ./patches/composer/patch.patch
 - Switch back to master - Switching branch will delete changed files
 - Restore original files (rm vendor/module folder and then run composer install)
 - Update composer.json as above
 - composer install (to patch)

To reapply patch rm ./vendor and composer install

Any tweaks to patch wording composer update --lock