schema2typebox/src/cli/cli.ts

Creates typebox code from JSON schemas

import minimist from "minimist";
import { createWriteStream, readFileSync } from "node:fs";
import { Readable } from "node:stream";

import packageJson from "../../package.json";
import { schema2typebox } from "../programmatic-usage";

export const runCli = async () => {
  const args = minimist(process.argv.slice(2), {
    alias: {
      input: "i",
      output: "o",
      help: "h",
    },
    default: {
      input: "schema.json",
      output: "generated-typebox.ts",
    },
  });

  // TODO: narrow condition.
  if (args.help) {
    return process.stdout.write(getHelpText.run());
  }

  const inputFileAsString = readFileSync(
    process.cwd() + `/${args.input ?? "schema.json"}`,
    "utf-8"
  );
  const typeboxCode = await schema2typebox({
    input: inputFileAsString,
  });

  const generatedCodeStream = Readable.from(typeboxCode.split(/(\r\n|\r|\n)/));
  if (args["output-stdout"]) {
    return generatedCodeStream.pipe(process.stdout);
  }

  const outputPath =
    process.cwd() + `/${args.output ?? "generated-typebox.ts"}`;
  return generatedCodeStream.pipe(createWriteStream(outputPath));
};

/**
 * Declaring this as function in order to make it better testable.
 * Using an object to be able to mock it and track its usage.
 */
export const getHelpText = {
  run: () => {
    return `
    schema2typebox generates TypeBox code from JSON schemas. The generated
    output is formatted based on the prettier config inside your repo (or the
    default one, if you don't have one). Version: ${packageJson.version}

    Usage:

    schema2typebox [ARGUMENTS]

    Arguments:

    -h, --help
       Displays this menu.

    -i, --input
       Specifies the relative path to the file containing the JSON schema that
       will be used to generated typebox code. Defaults to "schema.json".

    -o, --output
       Specifies the relative path to generated file that will contain the
       typebox code. Defaults to "generated-typebox.ts".

    --output-stdout
       Does not generate an output file and prints the generated code to stdout
       instead. Has precedence over -o/--output.
   `;
  },
};