Editing values during build via hooks - ionic2

Question

Im trying to edit a version variable when I build my applications, but I can't get any scripts to run using the cordova hooks at all.
I want to get the version from the package.json and the last 5 digits of the git commit so i can have something like 1.0.0.89gkt as my versions.
In the past for ionic 1 and using grunt or gulp I was able to add the scripts into the build process easily.
I've tried both the old way using the hooks/hook_name/script format and using the hook tag in the config.xml and neither work for me.
Overwriting the ionic scripts via the package.json allows me to change the scripts that are automatically run, but I want to avoid that if I can. Though I can easily add my text replace to one of the copy scripts or something (ill need to work out which one is best)
If someone knows a better way or a reason as to why the hooks wont fire, please let me know.

Answer 1

This is the solution that I ended up using.
scripts/before_prepare_increment_build_number.js
var fs = require('fs');
var git = require('git-rev-sync')
console.log('Incrementing Build Number');
var file = fs.readFileSync('www/build/main.js', 'utf8');
var str = git.short();
console.log('short', str)
var result = file.replace(/{{GITVERSIONSTRING}}/g, str);
fs.writeFileSync('www/build/main.js', result);
console.log('Incrementing Build Number Completed');
config.xml
<hook src="scripts/before_prepare_increment_build_number.js" type="before_prepare"/>
I needed to ensure that everything was happening synchronously otherwise the built in scripts would start copying before the strings had been replaced.
Currently its targeting the whole main.js that is generated by the default ionic-app-scripts so all comparisons and replacements can be added as required.
This solution uses the built in cordova hook before_prepare
Another solution that can be used to make it a bit more efficient is targeting the individual files as required and adding the script before the build/serve scripts in the package.json and have npm control and manage it.
Inside your package.json you could add a script to a prepare hook.
"scripts": {
"prepare": "node increment_build_number.js",
}