esm.sh loader

esm_sh-loader.js

import { createRequire } from "node:module";
import { pathToFileURL } from "node:url";

/**
 * @import { ResolveHookContext, ResolveFnOutput, Module } from "node:module"
 */

const localRequire = createRequire(pathToFileURL("."));

/**
 * @type (specifier: string, context: ResolveHookContext, nextResolve: (specifier: string, context?: Partial<ResolveHookContext>) => Promise<ResolveFnOutput>) => Promise<ResolveFnOutput>
 */
export async function resolve(specifier, context, nextResolve) {
  if (specifier.startsWith("https://esm.sh")) {
    return {
      shortCircuit: true,
      url: specifier
    };
  }

  if (context.parentURL?.startsWith("https://esm.sh")) {
    if (specifier.startsWith("/")) {
      // Handle relative path
      return {
        shortCircuit: true,
        url: new URL(specifier, context.parentURL).href
      };
    } else {
      // Handle external module
      return {
        shortCircuit: true,
        url: pathToFileURL(localRequire.resolve(specifier)).href
      };
    }
  }

  return nextResolve(specifier, context);
}

/**
 * @type (url: string, context: Module.LoadHookContext, nextLoad: (url: string, context?: Partial<Module.LoadHookContext>) => Promise<Module.LoadFnOutput>) => Promise<Module.LoadFnOutput>
 */
export async function load(url, _context, nextLoad) {
  if (url.startsWith("https://esm.sh")) {
    const response = await fetch(url);
    return {
      format: "module",
      source: await response.text(),
      shortCircuit: true
    };
  }

  return nextLoad(url);
}

try.js

import { register } from "node:module";
import { registerSchema, validate } from "@hyperjump/json-schema";

register("./esm_sh-loader.mjs", import.meta.url);

const packageId = "gh/jdesrosiers/json-schema-dialect-example@5462150";
const loadDialect = await import(`https://esm.sh/${packageId}?external=@hyperjump/json-schema,@hyperjump/browser`);
loadDialect.default();

const schemaUri = "https://example.com/main";
registerSchema({
  $schema: "https://example.com/dialect/example",

  foo: "foo",
  bar: 42
}, schemaUri);

const output = await validate(schemaUri, 42);
console.log(output);