zx: go back through tags to look for a specific string in a file

find-string-in-file-at-tag.mjs

#!/usr/bin/env zx

$.verbose = false;

const MAX_v2_MINOR = 18;
let version = { major: 3, minor: 28, patch: 0 };
version.toString = function () {
  return `v${this.major}.${this.minor}.${this.patch}`;
};
version.decrementMinor = function () {
  if (this.minor > 0) {
    this.minor -= 1;
  } else {
    if (this.major === 3) {
      this.major = 2;
      this.minor = MAX_v2_MINOR;
    } else {
      throw new Error(`Cannot decrement: ${version}`);
    }
  }
};

async function tagExists(version) {
  try {
    let result = await $`git tag -l ${version}`;
    return true;
  } catch (p) {
    return p.exitCode === 0;
  }
}

async function checkForString(string, filepath, tag) {
  await $`git checkout ${tag}`;
  if (!fs.existsSync(filepath)) {
    throw new Error(`path ${filepath} doesn't exist`);
  }
  try {
    await $`cat ${filepath} | grep ${string}`;
    return true;
  } catch (p) {
    return p.exitCode === 0;
  }
}

while (true) {
  console.log(`Checking Version: ${version}`);
  let exists = await tagExists(version);
  if (!exists) {
    console.log(`Skipping version ${version}`);
  } else {
    let str = "index(";
    let filepath = "lib/broccoli/ember-app.js";
    let isFound = await checkForString(str, filepath, version.toString());
    if (isFound) {
      console.log(`FOUND! "${str}" at ${filepath} for version ${version}`);
    }
  }

  version.decrementMinor();
}