AMD define() in UMD wrapper breaks Turbopack production builds

[johanhenrikssn]

Summary

Every source file is wrapped in a UMD wrapper that includes an AMD define() branch. This breaks Turbopack (the default bundler in Next.js 16+) during production builds with TP1200: unsupported AMD define() form, even when the package is marked as an external dependency.

The AMD branch is unreachable dead code, since this is a Node.js-only package and Node.js has never supported AMD natively. Removing the AMD branch from the codegen template would fix Turbopack without breaking any existing consumer.

Environment

• docusign-esign@8.7.0
• next@16.2.3 (Turbopack, default in Next.js 16+)
• Node.js 24

Error

Error: Turbopack build failed with 2 errors:
./node_modules/docusign-esign/src/Configuration.js:4:5
TP1200 unsupported AMD define() dependency element form

./node_modules/docusign-esign/src/index.js:14:5
TP1200 unsupported AMD define() form

Turbopack does not implement an AMD parser. Marking the package as external via serverExternalPackages or turbopack.resolveAlias does not help, because Turbopack's externals-tracing phase still parses the files during production builds and fails on the AMD branch.

Root cause

Every file in node_modules/docusign-esign/src/ uses a UMD wrapper, e.g.:

(function(root, factory) {
  if (typeof define === 'function' && define.amd) {
    define([undefined, './ApiClient'], factory);  // <-- fails here
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory(undefined, require('./ApiClient'));
  } else {
    root.Docusign = {};
    factory(root.Docusign, root.Docusign.ApiClient);
  }
}(this, function(module, ApiClient) {
  // ...
}));

In Node.js, define is never defined, so the AMD branch never executes. Only the CommonJS branch runs. The AMD branch is left over from the Swagger/OpenAPI codegen UMD template.

Why AMD should be removed

AMD (Asynchronous Module Definition) was a community specification from ~2011 for async module loading in browsers via RequireJS.

• AMD was never standardized in any TC39 spec.
• Node.js has never supported AMD natively. AMD was a browser pattern, requiring RequireJS or a similar loader.
• RequireJS itself is end-of-life: it was moved to OpenJS Foundation Emeritus status and is no longer actively developed.
• ES Modules (ESM) have been the official JavaScript module standard since ES2015 and are natively supported in modern browsers and Node.js (>=12).
• No modern bundler parses AMD except webpack, which retains support only for legacy compatibility. Turbopack, Vite/Rollup, and esbuild do not implement an AMD parser.

Since this is published as a Node.js SDK (it depends on superagent, uses fs/path/crypto, etc.), the AMD and browser-globals branches of the UMD wrapper are dead code in every environment the package actually runs in. Removing them is a non-breaking change.

Suggested fix

The .swagger-codegen-ignore file at the root of this repo confirms src/ is regenerated from Swagger Codegen, with only src/OAuth.js, src/RestApi.js, and src/oauth/ exempted from regeneration. The fix is to update the JavaScript client's UMD wrapper template (the mustache template that emits the (function(root, factory) { ... }(this, function(...) { ... })) shell around every file) to emit plain CommonJS, then regenerate.

Before (UMD with AMD branch, ~8 lines of boilerplate per file):

(function(root, factory) {
  if (typeof define === 'function' && define.amd) {
    define([undefined, './ApiClient'], factory);
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory(undefined, require('./ApiClient'));
  } else {
    root.Docusign = {};
    factory(root.Docusign, root.Docusign.ApiClient);
  }
}(this, function(module, ApiClient) {
  // ...
}));

After (plain CommonJS):

const ApiClient = require('./ApiClient');
// ...
module.exports = SomeClass;

An ESM codegen target would also work and would additionally let downstream bundlers tree-shake unused models.

Current workaround

We are using pnpm patch to replace the AMD condition with false in all 623 generated files:

- if (typeof define === 'function' && define.amd) {
+ if (false) {

This disables the AMD branch so Turbopack skips it. It works, but every consumer on a modern bundler has to maintain their own patch.

Impact

This blocks any Next.js 16+ project from using Turbopack for production builds (which is now the default; webpack is no longer shipped as the default bundler). It also affects any Vite, Rollup, or esbuild-based project, though those are less commonly used for SSR Node.js apps that integrate with DocuSign.