file inliner to inline markdown code into swagger documents

index.js

#!/usr/bin/env node
const commandLineArgs = require('command-line-args');
const fs = require('fs');

String.prototype.replaceAll = function (search, replacement) {
    const target = this;
    return target.replace(new RegExp(search, 'g'), replacement);
};


const optionDefinitions = [
    {name: 'sourceFile', alias: 's', type: String},
    {name: 'outputFile', alias: 'o', type: String},
    {name: 'relativeResolvePath', alias: 'b', type: String},
];

const options = commandLineArgs(optionDefinitions);

if(options["sourceFile"] === undefined){
    console.log("parameter s (sourceFile) is needed")
    process.exit(-1)
}
if(options["outputFile"] === undefined){
    console.log("parameter o (outputFile) is needed")
    process.exit(-1)
}
if(options["relativeResolvePath"] === undefined){
    options["relativeResolvePath"] = __dirname;
    process.exit(-1)
}

async function escapeFileIntoString(filePath) {
    let replacement = await readFile(options['relativeResolvePath'] + "/" + filePath);
    replacement = replacement.replaceAll(/\\/, '\\\\');
    replacement = replacement.replaceAll(/\n/, '\\n');
    replacement = replacement.replaceAll(/\r/, '\\r');
    replacement = replacement.replaceAll(/"/, '\\"');
    return replacement
}

function readFile(filePath) {
    return new Promise((resolve, reject) => {
        fs.readFile(filePath, 'utf8', function (err, contents) {
            if (err) reject(err);
            resolve(contents)
        });
    });
}

(async () => {
    console.log(options);

    let content = await readFile(options["sourceFile"]);

    const placeholderPattern = /(\${{file:\/\/([\.\w\/]*)}})/;

    const contentArr = content.split('\n');

    await new Promise(resolve => {
        let countDown = contentArr.length;

        contentArr.forEach(async (elem, index, arr) => {
            const match = elem.match(placeholderPattern);
            if (match && match.length > 1) {
                const fileToBeResolved = match[2];
                const replacement = await escapeFileIntoString(fileToBeResolved);
                arr[index] = elem.replace(match[1], replacement)
            }
            countDown--;
            if (countDown < 1) {
                resolve();
            }
        });

    });


    fs.writeFile(options["outputFile"], contentArr.join('\n'), function (err) {
        if (err) {
            return console.log(err);
        }
    });


})().catch(console.error);

package.json

{
  "name": "file-inliner",
  "version": "0.0.1",
  "description": "tool to inline ${{file://file.txt}} into a file",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Constantin-Marius Jaeck",
  "license": "MIT",
  "bin": {
    "file-inliner": "./index.js"
  },
  "dependencies": {
    "command-line-args": "^5.0.2"
  }
}