Script to clean unused icons in ionic

cleanIcon.js

#!/bin/env node
let path = require('path'), fs=require('fs');

function fromDir(startPath, filter, callback){

    if (!fs.existsSync(startPath)){
        console.log("no dir ",startPath);
        return;
    }

    let files = fs.readdirSync(startPath);
    for (let i = 0; i < files.length; i++) {
        let filename = path.join(startPath,files[i]);
        let stat = fs.lstatSync(filename);
        if (stat.isDirectory()) {
            fromDir(filename, filter, callback); //recurse
        }
        else if (filter.test(filename)) {
            callback(filename, files[i])
        }
    }
}

function justPrint(filePath, fileName){
    console.log('-- found: ', fileName.split('.')[0]);
}

let iconNames = []
function addTolist(filePath, fileName) {
    iconNames.push({
        iconName: fileName.split('.')[0],
        filePath,
        used: false
    })
}

function checkIfUnsused(filePath, fileName) {
    let data = fs.readFileSync(filePath)
    iconNames.forEach((icon, index, iconList) => {
        if (data.includes(`["name","${icon.iconName}"]`) || // for Angular 8 / view engine
            data.includes(`"name","${icon.iconName}"`) || // for Angular 9+ / ivy
            data.includes(`name:"${icon.iconName}"`) || 
            data.includes(`icon:"${icon.iconName}"`) || 
            data.includes(`"backButtonIcon","${icon.iconName}"`)) { // for stenciljs
            console.log('--- icon used', icon.iconName)
            iconList[index].used = true;
        }
    })
}

fromDir('www/svg',/\.svg$/, justPrint);
fromDir('www/svg',/\.svg$/, addTolist);
fromDir('www',/\.(js|css|html)$/, checkIfUnsused);

iconNames.forEach((icon) => {
    if(!icon.used){
        console.log('--- will delete unused icon', icon.iconName)
        fs.unlink(icon.filePath, (err) => {
            if (err) {
                console.error(err);
            }
        })
    }
})

Thanks for this script!
In case someone can use our approach:
https://github.com/rodekruis/cash-program-design-wizard/pull/356/files

In our version of the script I use a hard-coded list of icons in the angular.json-file, which should be updated manually every time you use a new icon (unfortunately), but the new list will be generated for you, so it's easy to fix when forgotten.

With the explicit list of icons there, all other icons will never be copied to the www/svg-folder, so no need to delete anything.

Hope it can help someone else.

I know it's been a long time but thank you @nucklehead and to all contributors to this script, kudos to you all 🙏🏼