Function resolveEsmPath

test/helpers/getImplementationByName.js:17–50

* Resolve the absolute filesystem path of a package's ESM entry, walking * the `exports` field's `node` / `import` / `default` conditions. Used by * the "sass_string" / "sass_file_url" fixtures so the loader's * `await import( )` returns a real ESM namespace (with `info`, * `compileStringAs

(specifier)

 * @returns {string} absolute filesystem path
 */
function resolveEsmPath(specifier) {
  const pkgPath = findPackageJSON(
    specifier,
    new URL("../../src/utils.js", import.meta.url),
  );
  const pkg = JSON.parse(readFileSync(pkgPath, "utf8"));

  const walk = (node) => {
    if (typeof node === "string") return node;
    if (Array.isArray(node)) {
      for (const item of node) {
        const r = walk(item);
        if (r) return r;
      }
    }
    if (node && typeof node === "object") {
      for (const key of ["node", "import", "default"]) {
        if (key in node) {
          const r = walk(node[key]);
          if (r) return r;
        }
      }
    }
    return null;
  };

  const entry =
    (pkg.exports && walk(pkg.exports["."] ?? pkg.exports)) ??
    pkg.module ??
    pkg.main ??
    "index.js";

  return path.join(path.dirname(pkgPath), entry);
}

/**
 * @param {"dart-sass" | "sass" | "sass-embedded" | "sass_string" | "sass_file_url"} implementationName implementation name