create_dummy_test.js

#!/usr/bin/env node

const dest = __dirname + "/../packages/";
const { readdir, writeFile, exists, mkdir } = require("fs");
const { promisify } = require("util");
const [readDirAsync, writeFileAsync, existsAsync, mkdirAsync] = [
  promisify(readdir),
  promisify(writeFile),
  promisify(exists),
  promisify(mkdir)
];
var shell = require("shelljs");

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;
      }
      const packageName = dirName.replace(/_/g, "");
      try {
        const androidTestPath =
          __dirname +
          "/../packages/" +
          dirName +
          "/android/src/test/java/io/flutter/plugins/" +
          packageName;

        if (!(await existsAsync(androidTestPath))) {
          shell.mkdir("-p", androidTestPath);
        }

        let dirContent = await readDirAsync(androidTestPath);
        if (dirContent.length !== 0) {
          return;
        }

        const content = `package io.flutter.plugins.${packageName}

import org.junit.Assert.assertNull
import org.junit.Test

class DummyTest {

}
`;

        await writeFileAsync(androidTestPath + "/dummy.kt", content);
      } catch (e) {
        console.log(e);
      }
    });
};

main();