require.ts

import fs from "node:fs/promises";

import type { PluginBuild } from "esbuild";

export default function fixRequire() {
  return {
    name: "fix-require",

    setup: async (build: PluginBuild) => {
      build.onLoad({ filter: /.*/ }, async ({ path }) => {
        let contents = await fs.readFile(path, "utf-8");

        // `eval(...)` is not supported by workerd.
        contents = contents.replaceAll(`eval("require")`, "require");

        // `@opentelemetry` has a few issues.
        //
        // Next.js has the following code in `next/dist/server/lib/trace/tracer.js`:
        //
        //     try {
        //       api = require('@opentelemetry/api');
        //     } catch (err) {
        //       api = require('next/dist/compiled/@opentelemetry/api');
        //     }
        //
        // The intent is to allow users to install their own version of `@opentelemetry/api`.
        //
        // The problem is that even when users do not explicitely install `@opentelemetry/api`,
        // `require('@opentelemetry/api')` resolves to the package which is a dependency
        // of Next.
        //
        // The second problem is that when Next traces files, it would not copy the `api/build/esm`
        // folder (used by the `module` conditions in package.json) it would only copy `api/build/src`.
        // This could be solved by updating the next config:
        //
        //     const nextConfig: NextConfig = {
        //       // ...
        //       outputFileTracingIncludes: {
        //         "*": ["./node_modules/@opentelemetry/api/build/**/*"],
        //       },
        //     };
        //
        // We can consider doing that when we want to enable users to install their own version
        // of `@opentelemetry/api`. For now we simply use the pre-compiled version.
        contents = contents.replace(
          /require\(.@opentelemetry\/api.\)/g,
          `require("next/dist/compiled/@opentelemetry/api")`
        );

        return { contents };
      });
    },
  };
}