sebmck/6to5

// @flow

import invariant from "invariant";
import semver from "semver";

import { unreleasedLabels } from "./targets";
import type { Target, Targets } from "./types";

const versionRegExp = /^(\d+|\d+.\d+)$/;

export function semverMin(first: ?string, second: string): string {
  return first && semver.lt(first, second) ? first : second;
}

// Convert version to a semver value.
// 2.5 -> 2.5.0; 1 -> 1.0.0;
export function semverify(version: number | string): string {
  if (typeof version === "string" && semver.valid(version)) {
    return version;
  }

  invariant(
    typeof version === "number" ||
      (typeof version === "string" && versionRegExp.test(version)),
    `'${version}' is not a valid version`,
  );

  const split = version.toString().split(".");
  while (split.length < 3) {
    split.push("0");
  }
  return split.join(".");
}

export function isUnreleasedVersion(
  version: string | number,
  env: string,
): boolean {
  const unreleasedLabel = unreleasedLabels[env];
  return (
    !!unreleasedLabel && unreleasedLabel === version.toString().toLowerCase()
  );
}

export function getLowestUnreleased(a: string, b: string, env: string): string {
  const unreleasedLabel = unreleasedLabels[env];
  const hasUnreleased = [a, b].some(item => item === unreleasedLabel);
  if (hasUnreleased) {
    return a === hasUnreleased ? b : a || b;
  }
  return semverMin(a, b);
}

export function getLowestImplementedVersion(
  plugin: Targets,
  environment: Target,
): string {
  const result = plugin[environment];
  // When Android support data is absent, use Chrome data as fallback
  if (!result && environment === "android") {
    return plugin.chrome;
  }
  return result;
}