Derp

An experiment on exploring an application's required files.

This will parse your code (using nikic/php-parser) and try to detect every PHP file that is needed to make your app run.

Please note: this is only a POC and there ARE bugs (I don't know what bugs, but it's 100% guaranteed that they exist).

Is this useful?

I don't really know, you tell me. It started as an experiment to reduce AWS Lambda packages size. Since size (kinda) is a factor, I wanted to see how far we could go in reducing an app's footprint.

Right now, using this to package itself, here are the resulting packages sizes:

9.9M    derp
1.7M    derp-packaged

And number of files:

2182    derp
347     derp-packaged

But honestly, the most useful feature right now is the why command that will tell you why a file is required.

Usage

Clone this repository somewhere:

git clone https://github.com/ubermuda/derp.git

Create a manifest.json file in your app's root directory. This file must contain a valid JSON valid object with the following keys:

• include (mandatory), the files that the tool should parse (generally, your app's index.php). Supports globing (through fname).
• autoload (mandatory), your autoloading strategy (right now, only composer is supported)

So for example, if your app's entry point is index.php, your manifest will look something like this:

{
    "include": [
        "index.php"
    ],

    "autoload": "composer"
}

You can also exclude classes with the exclude-class setting (like for include, globing is supported). It is useful when a class cannot be autoload because a dependency is missing (happens for example if your app has non-mandatory features based on what's installed and what's not). See this repository's manifest.json for an example.

Then, run the tool:

$ php bin/derp ../my-app/manifest.json print

This will list the files required to run your application.

Having just that raw list is not really useful, so Derp comes with some other commands:

• why, shows you why a certain file is required
• package, packages your application with only the required files

Run php bin/derp for more information.