check_licence.ts

// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
import { walk } from "../fs/walk.ts";
import { globToRegExp } from "../path/glob.ts";

const EXTENSIONS = [".mjs", ".js", ".ts", ".rs"];
const EXCLUDED_DIRS = [
  "**/dotenv/testdata",
  "**/fs/testdata",
  "**/http/testdata",
  "**/crypto/_wasm/target",
];

const ROOT = new URL("../", import.meta.url);
const CHECK = Deno.args.includes("--check");
const FIRST_YEAR = 2018;
const CURRENT_YEAR = new Date().getFullYear();
const RX_COPYRIGHT = new RegExp(
  `// Copyright ([0-9]{4})-([0-9]{4}) the Deno authors\\. All rights reserved\\. MIT license\\.\n`,
);
const COPYRIGHT =
  `// Copyright ${FIRST_YEAR}-${CURRENT_YEAR} the Deno authors. All rights reserved. MIT license.`;

let failed = false;

for await (
  const { path } of walk(ROOT, {
    exts: EXTENSIONS,
    skip: EXCLUDED_DIRS.map((path) => globToRegExp(path)),
    includeDirs: false,
  })
) {
  const content = await Deno.readTextFile(path);
  const match = content.match(RX_COPYRIGHT);

  if (!match) {
    if (CHECK) {
      console.error(`Missing copyright header: ${path}`);
      failed = true;
    } else {
      const contentWithCopyright = COPYRIGHT + "\n" + content;
      await Deno.writeTextFile(path, contentWithCopyright);
      console.log("Copyright header automatically added to " + path);
    }
  } else if (
    parseInt(match[1]) !== FIRST_YEAR || parseInt(match[2]) !== CURRENT_YEAR
  ) {
    if (CHECK) {
      console.error(`Incorrect copyright year: ${path}`);
      failed = true;
    } else {
      const index = match.index ?? 0;
      const contentWithoutCopyright = content.replace(match[0], "");
      const contentWithCopyright = contentWithoutCopyright.substring(0, index) +
        COPYRIGHT + "\n" + contentWithoutCopyright.substring(index);
      await Deno.writeTextFile(path, contentWithCopyright);
      console.log("Copyright header automatically updated in " + path);
    }
  }
}

if (failed) {
  console.info(`Copyright header should be "${COPYRIGHT}"`);
  Deno.exit(1);
}