I'm worndering if it is double transform with wranger deploy. Can you spot same issue in .output / dist/_worker also?

Hello -- thanks for the quick response! I'm not sure exactly what you mean... .output doesn't contain any files in my Nitro build:

fd . .output
.output/public/
.output/server/

I don't think it's a double transform issue, though -- this would arise from a single transform. The package contains a line of code that's something like

const blah = "if (typeof window === 'undefined') ...";

When Rollup applies its search-and-replace, the resulting source code is

const blah = "if ("undefined" === 'undefined') ...";`

This causes a syntax error when the build process actually tries to parse the module.

Nitro output for cloudflare-module presets goes into .output/server/* dir.

the resulting source code is

Do you see this issue in a file inside .output/server/* files when using build --preset cloudflare-module

(consider before deploy, wrangler always does another transform step)

I don't see the issue in .output/server; that directory is empty. (I think the build fails before emitting anything there?)

I see the issue in the full log output; sorry, here that is:

npm run build

> build
> nitro build

✔ Generated public .output/public                                                                                                          nitro 11:04:56 AM
ℹ Building Nitro Server (preset: cloudflare-module, compatibility date: 2025-01-31)                                                        nitro 11:04:56 AM

 ERROR  RollupError: Expected ',', got 'undefined' in [...]/nitro/node_modules/papaparse/papaparse.js                          nitro 11:04:56 AM


50:     var URL = global.URL || global.webkitURL || null;
51:     var code = moduleFactory.toString();
52:     return Papa.BLOB_URL || (Papa.BLOB_URL = URL.createObjectURL(new Blob(["var global = (function() { if (typeof self !== 'undefined') { return self; } if ("undefined"...
                                                                                                                                                                  ^
53:   }


 ERROR  Expected ',', got 'undefined' in [...]/nitro/node_modules/papaparse/papaparse.js                                             11:04:56 AM

    at getRollupError (node_modules/rollup/dist/es/shared/parseAst.js:397:41)
    at convertProgram (node_modules/rollup/dist/es/shared/parseAst.js:1085:26)
    at parseAst (node_modules/rollup/dist/es/shared/parseAst.js:2070:87)
    at tryParse (node_modules/@rollup/plugin-commonjs/dist/es/index.js:17:12)
    at analyzeTopLevelStatements (node_modules/@rollup/plugin-commonjs/dist/es/index.js:37:15)
    at Object.transformAndCheckExports (node_modules/@rollup/plugin-commonjs/dist/es/index.js:2113:68)
    at Object.transform (node_modules/@rollup/plugin-commonjs/dist/es/index.js:2317:41)
    at node_modules/rollup/dist/es/shared/node-entry.js:21838:40



 ERROR  Expected ',', got 'undefined' in [...]/nitro/node_modules/papaparse/papaparse.js

I tried npm run build --preset cloudflare-module and the build completed successfully, but still nothing was generated in the server directory. (I have preset set in the config; I linked adorack/nitro-error@fe1f99f in the ticket description, which is the diff from the starter project.)

Oh, weird -- I do see output in cloudflare-module/.output/server -- but it doesn't look like this is pulling in PapaParse; I don't see the offending code fragment at all.

cloudflare-module/.output/server it seems wrong build/rootDir.

Your issue stands correct and I checked locally, it happens for any builds without having external (output/server/node_modules) support, and cloudflare is currently one of them.

Your solution is also nice. Sadly we cannot either change or drop this change as it breaks other places that depend on this tree-shaking method. If you like to contribute to docs perhaps additing a section to end of cloudflare.md it is more than welcome 🙏🏼

OK -- thank you for looking into it.

Sadly we cannot either change or drop this change as it breaks other places that depend on this tree-shaking method.

I'm happy to make a small docs PR (probably tomorrow at this point). However, is there any further explanation for what this tree-shaking accomplishes that I can link to or describe? Is it that it's somehow allowing a compiler to exclude branches that are client-only or server-only, and that compiler refuses to make assumptions about the window object?

Yes exactly it is to guide compiler to remove such branches. Both to eliminate code and remove incompatible code paths.

This is indeed a bug. Replacing arbitrary code like this globally and without considering the AST will inevitably lead to incredibly difficult to debug problems. This bug is also triggered in combination with effect: Effect-TS/effect#3864

In our case, this configuration causes typeof window to be replaced in a string which it should absolutely not do.