append.js

#!/usr/bin/env node

const dest = __dirname + "/../packages/";
const { readdir, readFile, writeFile } = require("fs");
const { promisify } = require("util");
const [readDirAsync, writeFileAsync, readFileAsync] = [
  promisify(readdir),
  promisify(writeFile),
  promisify(readFile)
];
const rp = require("request-promise-native");
const { JSDOM } = require("jsdom");

class Lazy {
  constructor(iterable, callback) {
    this.iterable = iterable;
    this.callback = callback;
  }

  filter(callback) {
    return new LazyFilter(this, callback);
  }

  map(callback) {
    return new LazyMap(this, callback);
  }

  next() {
    return this.iterable.next();
  }

  take(n) {
    const values = [];
    for (let i = 0; i < n; i++) {
      values.push(this.next().value);
    }

    return values;
  }
}

class LazyFilter extends Lazy {
  next() {
    while (true) {
      const item = this.iterable.next();

      if (this.callback(item.value)) {
        return item;
      }
    }
  }
}

class LazyMap extends Lazy {
  next() {
    const item = this.iterable.next();

    const mappedValue = this.callback(item.value);
    return { value: mappedValue, done: item.done };
  }
}

const main = async () => {
  const dirList = await readDirAsync(dest);
  const dirListGenerator = new Lazy(
    (function*() {
      for (let i = 0; i < dirList.length; i++) {
        yield dirList[i];
      }
    })()
  );
  dirList
    // dirListGenerator
    .map(async dirName => {
      if (!dirName) {
        return;
      }
      try {
        // const packageAndroidContent = await readDirAsync(__dirname + "/../packages/" + dirName + "android/src");
        const gradlePath =
          __dirname + "/../packages/" + dirName + "/android/build.gradle";
        const gradleContent = await readFileAsync(gradlePath);
        const gradleContentString = gradleContent.toString();
        const matches = gradleContentString.match(/\n\ndependencies \{/i);
        if (matches) {
          return;
        }

        const content =
          gradleContentString +
          `
dependencies {
    testImplementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    testImplementation 'junit:junit:4.12'
}
`;

        await writeFileAsync(gradlePath, content);
      } catch (e) {
        console.log(e);
      }
    });
};

main();