HelloWorldCheckerPlugin.js

const fs = require('fs');
const path = require('path');

class HelloWorldCheckerPlugin {
    constructor(options) {
        this.options = options;
    }

    apply(compiler) {
        compiler.plugin('make', (compilation, cb) => this._make(compilation, cb));
    }

    _make(compilation, cb) {
        try {
            const file = fs.readFileSync(path.resolve('/', this.options.path), 'utf8');
            if (file.includes('Hello World!')) {
                console.log(`The file ${this.options.path} contains 'Hello World!' string`);
            } else {
                console.log(`The file ${this.options.path} doesn't contain 'Hello World!' string`)
            }
            cb();
        } catch (e) {
            compilation.errors.push(e);
            cb();
        }
    }
}

exports.HelloWorldCheckerPlugin = HelloWorldCheckerPlugin;