checksum

#!/usr/bin/env node

/**
 * Run this script (from root directory): npx babel-node scripts/checksum
 *
 * This will check root `package.json` matches each exercise's `package.json`.
 * But the catch is there are some dependencies used for build but not served to end users
 * We skip those dependencies while performing checksum.
 * See `SKIP_PACKAGES_FOR_CHECKSUM` in helpers.js for list of skipped packages.
 */

const shell = require("shelljs");
const helpers = require("./helpers");
const crypto = require("crypto");

const sha = (str) => crypto.createHash("md5").update(str).digest("hex");

// Helper function to check single assignment
function checksum(filename, assignment, rootChecksum) {
  if (!assignment) {
    return;
  }

  let assignmentConfig = shell
    .cat(["exercises", assignment, filename].join("/"))
    .toString();
  if (filename === "package.json") {
    const json = JSON.parse(assignmentConfig);
    delete json["version"];
    assignmentConfig = JSON.stringify(json, null, 2) + "\n";
  }
  const assignmentChecksum = sha(assignmentConfig);

  if (assignmentChecksum !== rootChecksum) {
    shell.echo(`[Failure] ${filename} did not match for ${assignment}`);
    shell.exit(1);
  }
}

// Check all assignments by default
// or single if ASSIGNMENT is given
function checkSumAll(filename, rootFileName = filename) {
  const assignment = shell.env["ASSIGNMENT"];

  shell.echo(`Checking integrity of ${assignment}/${filename}...`);

  const config = shell.cat(rootFileName).toString();
  const rootChecksum = sha(config);

  if (assignment) {
    checksum(filename, assignment, rootChecksum);
  } else {
    helpers.assignments.forEach((assignment) =>
      checksum(filename, assignment, rootChecksum)
    );
  }
}

helpers.createExercisePackageJson();
checkSumAll("package.json", "exercise-package.json");
shell.rm("exercise-package.json");

checkSumAll("babel.config.js");
checkSumAll(".eslintrc");
checkSumAll(".npmrc");