resolveErrors.ts

import { Package } from "@manypkg/get-packages";
import path from "node:path";
import normalizePath from "normalize-path";
import { Plugin } from "rollup";
import { PackagePredicate } from "../makePackagePredicate";

// bundled dependencies complicated this a lot and currently this might not serve its original purpose
// the rules inside this could use some improvement
// ideally the rules that check if something starts with / would be rewritten
export function resolveErrors({
  isExternal,
  pkg,
}: {
  isExternal: PackagePredicate;
  pkg: Package;
}): Plugin {
  return {
    name: "resolve-errors",
    // based on https://github.com/preconstruct/preconstruct/blob/5113f84397990ff1381b644da9f6bb2410064cf8/packages/cli/src/rollup-plugins/resolve.ts
    async resolveId(source, importer, options) {
      if (
        options.isEntry ||
        source.startsWith("\0") ||
        options.custom?.["bundled-dependencies"] ||
        importer?.startsWith("/")
      ) {
        return;
      }
      if (!source.startsWith(".") && !source.startsWith("/") && !isExternal(source)) {
        throw new Error(
          `"${source}" is imported ${
            importer ? `by "${importer}" ` : ""
          }but the package is not specified in dependencies or peerDependencies`
        );
      }
      const resolved = await this.resolve(source, importer, options);

      if (resolved === null) {
        if (!source.startsWith(".")) {
          throw new Error(
            `"${source}" is imported ${
              importer ? `by "${normalizePath(path.relative(pkg.relativeDir, importer))}" ` : ""
            }but the package is not specified in dependencies or peerDependencies`
          );
        }
        throw new Error(
          `Could not resolve ${source} ` +
            (importer ? `from ${path.relative(pkg.relativeDir, importer)}` : "")
        );
      }

      if (resolved.id.startsWith("\0") || resolved.id.startsWith(pkg.dir)) {
        return resolved;
      }

      throw new Error(
        `all relative imports in a package should only import modules inside of their package directory but ${
          importer ? `"${normalizePath(path.relative(pkg.relativeDir, importer))}"` : "a module"
        } is importing "${source}"`
      );
    },
  };
}