Hi! Can I do something to get this PR merged? I'm running into this exact issue.

My use case involves a root composer.json that merges several modular packages (e.g., module-a and module-b), each defining their own scripts. My goal is for the post-update-cmd arrays from all modules to be merged together. This would be the same behavior as merge-extra-deep.

My Setup

My root composer.json has:

{
    "name": "my-project/root",
    "extra": {
        "merge-plugin": {
            "include": [
                "modules/module-a/composer.json",
                "modules/module-b/composer.json"
            ],
            "merge-scripts": true,
            "merge-replace": false
        }
    }
}

modules/module-a/composer.json:

{
    "name": "my-project/module-a",
    "scripts": {
        "module-a:task1": "echo 'Running Task 1 from Module A'",
        "module-a:task2": "echo 'Running Task 2 from Module A'",
        "post-update-cmd": [
            "@module-a:task1",
            "@module-a:task2"
        ]
    }
}

modules/module-b/composer.json also defines its own scripts for the same event:

{
    "name": "my-project/module-b",
    "scripts": {
        "module-b:task1": "echo 'Running Task 1 from Module B'",
        "post-update-cmd": [
            "@module-b:task1"
        ]
    }
}

The Problem (Actual Behavior)

When I run composer update, only the scripts from the last module merged (module-b) are executed:

Actual result:

> echo 'Running Task 1 from Module B'

Expected Behavior

I expect the post-update-cmd arrays to be concatenated, so that scripts from all modules are executed.

Expected result:

> echo 'Running Task 1 from Module A'
> echo 'Running Task 2 from Module A'
> echo 'Running Task 1 from Module B'

Looking forward to seeing this merged!