publish.js

const path = require("path");
const execSync = require("child_process").execSync;

const jsonfile = require("jsonfile");
const semver = require("semver");

const rootDir = path.resolve(__dirname, "..");

function invariant(cond, message) {
  if (!cond) throw new Error(message);
}

function getTaggedVersion() {
  let output = execSync("git tag --list --points-at HEAD").toString();
  return output.replace(/^v|\n+$/g, "");
}

async function ensureBuildVersion(packageName, version) {
  let file = path.join(rootDir, "build", packageName, "package.json");
  let json = await jsonfile.readFile(file);
  invariant(
    json.version === version,
    `Package ${packageName} is on version ${json.version}, but should be on ${version}`
  );
}

function publishBuild(packageName, tag) {
  let buildDir = path.join(rootDir, "build", packageName);
  console.log();
  console.log(`  npm publish ${buildDir} --tag ${tag}`);
  console.log();
  execSync(`npm publish ${buildDir} --tag ${tag}`, { stdio: "inherit" });
}

async function run() {
  try {
    // 0. Ensure we are in CI. We don't do this manually
    invariant(
      process.env.CI,
      `You should always run the publish script from the CI environment!`
    );

    // 1. Get the current tag, which has the release version number
    let version = getTaggedVersion();
    invariant(
      version !== "",
      "Missing release version. Run the version script first."
    );

    // 2. Determine the appropriate npm tag to use
    let tag = semver.prerelease(version) == null ? "latest" : "next";

    console.log();
    console.log(`  Publishing version ${version} to npm with tag "${tag}"`);

    // 3. Ensure build versions match the release version
    await ensureBuildVersion("history", version);

    // 4. Publish to npm
    publishBuild("history", tag);
  } catch (error) {
    console.log();
    console.error(`  ${error.message}`);
    console.log();
    return 1;
  }

  return 0;
}

run().then((code) => {
  process.exit(code);
});