make-index.ts

#!/usr/bin/env ts-node
import { readdirSync, writeFileSync, lstatSync } from "fs";
import { join, basename } from "path";
import { format } from "prettier";
const base = ".";
export function getExports(
  base: string = ".",
  context = join(process.cwd(), "src")
): [string[], string[]][] {
  const files = readdirSync(join(__dirname, base));
  return files
    .filter(
      (file: string) =>
        base !== "." || !["index.ts", basename(__filename)].includes(file)
    )
    .map<[string[], string[]]>((file: string) => {
      if (lstatSync(join(__dirname, base, file)).isDirectory()) {
        return getExports(join(base, file), context).reduce(
          ([is, es], [i, e]) => [
            [...is, ...i],
            [...es, ...e],
          ],
          <[string[], string[]]>[[], []]
        );
      }
      const moduleName = basename(file).replace(/\.[^/.]+$/, "");
      const path = join(__dirname, base, file);
      if (!lstatSync(path).isFile()) return [[], []];
      try {
        const out = require(path);
        const keys = Object.keys(out);
        if (!keys.length) return [['import "./' + moduleName + '";'], []];
        let i = "import ";
        let e: string[] = [];
        if (keys.includes("default")) {
          i = i + moduleName + " ";
          e.push(moduleName);
        }
        const namedExports = keys.filter((key) => key !== "default");
        if (namedExports.length) {
          if (keys.includes("default")) i = i + ",";
          i =
            i +
            " {" +
            namedExports
              .map((x) => x + " as " + moduleName + "_" + x)
              .join(",") +
            "}";
          e.push(
            ...namedExports.map((x) => {
              return moduleName + "_" + x;
            })
          );
        }
        i = i + " from " + '"./' + moduleName + '";';
        return <[string[], string[]]>[[i], e];
      } catch (e) {
        console.error("That was not good at all at path", path);
        console.error((e as Error).message);
        console.error(JSON.stringify(e));
        process.exit(1);
      }
    })
    .filter(Boolean);
}
export function makeIndex(
  exports: [string[], string[]][],
  indexPath = "./src/index.ts"
) {
  const arr = exports.reduce(
    ([is, es], [i, e]) => [
      [...is, ...i],
      [...es, ...e],
    ],
    <[string[], string[]]>[[], []]
  );
  const out =
    "/** THIS FILE IS AUTO_GENERATED - MODIFICATIONS MAY NOT BE SAVED */\n" +
    arr[0].join("\n") +
    "\n export{" +
    arr[1].join(",") +
    "};";
  writeFileSync(indexPath, format(out, { parser: "typescript" }));
}

const [, , out] = process.argv;
const x = getExports(".");
makeIndex(x, out);