Function buildEsmModule

packages/unpkg-files/src/lib/esm-build-service.ts:179–235

(registry: string, request: BuildRequest)

}

export async function buildEsmModule(registry: string, request: BuildRequest): Promise<BuildResult | null> {
  let packageJsonFile = await getFile(registry, request.packageName, request.version, "/package.json");
  if (packageJsonFile == null) {
    return null;
  }

  let packageJson = JSON.parse(new TextDecoder().decode(packageJsonFile.body)) as PackageJson;
  let filename = resolveBuildFilename(packageJson, request.filename, request.options);
  if (filename == null) {
    return null;
  }
  if (isUnsupportedSourceFile(filename)) {
    throw new UnsupportedSourceTypeError(filename);
  }

  filename = await resolveExistingSourceFilename(registry, request.packageName, request.version, filename);
  if (filename == null) {
    return null;
  }

  let file = await getFile(registry, request.packageName, request.version, filename);
  if (file == null || !isSupportedSourceFile(filename)) {
    return null;
  }

  let code = new TextDecoder().decode(file.body);
  let deps = Object.assign({}, packageJson.peerDependencies, packageJson.dependencies);
  let transformed =
    request.options.bundleMode === "none"
      ? await transformSource(code, filename, request.options)
      : await withPackageFileDirectory(registry, request.packageName, request.version, (packageDirectory) =>
          bundleSource(packageDirectory, packageJson, request.packageName, request.version, filename, code, request.options)
        );
  let rewritten = await rewriteEsmImports(transformed.code, registry, request.options.origin, deps, request.options);
  let buildKey = createBuildKey(request, filename);
  let metadata: BuildMetadata = {
    buildKey,
    input: filename,
    output: `/${request.packageName}@${request.version}${request.filename ?? ""}`,
    packageName: request.packageName,
    target: request.options.target,
    version: request.version,
  };

  return {
    code: rewritten,
    headers: {
      "Cache-Control": moduleCacheControl,
      "Content-Type": "application/javascript; charset=utf-8",
      "X-UNPKG-Bundle-Mode": request.options.bundleMode,
      "X-UNPKG-Build-Key": buildKey,
      "X-UNPKG-Build-Input": filename,
      "X-UNPKG-Transformer": "esbuild",
    },
    metadata,
  };
}