wasm-bindgen: In wasm-bindgen 0.2.84 version, webpack cannot generate wasm files

Steps to Reproduce

I created a repo with the problem here

Step1: npm run i

Step2: wasm-pack build

Step3: npm run build

A dist dir contain index.js and wasm file will be generated in the project root; It is expected behavior.

When i change the wasm-bindgen version to 0.2.84 and run rm -r pkg && wasm-pack build && npm run build

In dist dir, webpack doesn’t generate wasm files.

About this issue

Original URL
State: closed
Created a year ago
Reactions: 7
Comments: 15 (2 by maintainers)

Commits related to this issue

fix(deps): temporarily pin wasm-bindgen to 0.2.83 to fix critical regression This regression rendered the OptiVorbis web demo unusable. Upstream issue: https://github.com/rustwasm/wasm-bindgen/issues... — committed to OptiVorbis/OptiVorbis by AlexTMjugador a year ago
Fixed the HDR Histogram build for webpack - https://github.com/rustwasm/wasm-bindgen/issues/3276#issuecomment-1475805578 - https://github.com/rustwasm/wasm-pack/pull/1224 — committed to FamilySearch/pewpew by tkmcmaster a year ago
Fix histogram (#119) * Fixed the HDR Histogram build for webpack - https://github.com/rustwasm/wasm-bindgen/issues/3276#issuecomment-1475805578 - https://github.com/rustwasm/wasm-pack/pull/1224 ... — committed to FamilySearch/pewpew by tkmcmaster a year ago

Most upvoted comments

I’ve noticed this as well, ~~additionally: setting the version of wasm-bindgen back to 83 isn’t respected for some reason, and cargo continues building with 84 regardless.~~

In my case, the files are being generated but they are invalid, and any use of them results in a javascript undefined.

hschimke on Feb 2, 2023

It turns out this is happening because wasm-pack sets "sideEffects": false for wasm-bindgen generated code, which is a Webpack-specific flag that tells Webpack it can remove any code whose only impact is a side effect. In #3152, I unwittingly made initialisation rely on side effects, causing this problem.

(So, it’s not a Webpack bug, I was a bit quick to assume that.)

I’ve opened rustwasm/wasm-pack#1224 to fix this. @alexcrichton or @drager, could you take a look at that PR?

Liamolucko on Feb 5, 2023

This is now fixed in wasm-pack v0.11.0.

Liamolucko on Mar 20, 2023

It turns out this is happening because wasm-pack sets "sideEffects": false for wasm-bindgen generated code, which is a Webpack-specific flag that tells Webpack it can remove any code whose only impact is a side effect. In #3152, I unwittingly made initialisation rely on side effects, causing this problem.

(So, it’s not a Webpack bug, I was a bit quick to assume that.)

I’ve opened rustwasm/wasm-pack#1224 to fix this. @alexcrichton or @drager, could you take a look at that PR?

Yeah, I will take a look soon. Thanks for looking into and fixing it!

drager on Feb 17, 2023

I have this exact issue, as soon as I upgrade to web_sys 0.3.61 from 0.3.60 any call to a Rust function from JavaScript results in an undefined error like:
bootstrap.js:2 Error importing `index.js`: TypeError: Cannot read properties of undefined (reading 'on_assembly_change')
    at Module.on_assembly_change (spcasm_web_bg.js:269:10)
    at eval (index.js:36:46)
    at __webpack_require__.a (bootstrap.js:357:13)
    at eval (index.js:1:21)
    at ./index.js (index_js.bootstrap.js:28:1)
    at __webpack_require__ (bootstrap.js:284:33)
    at Function.fn (bootstrap.js:592:21)
(on_assembly_change is the Rust function being called, which sort of has bindings generated, as you can see)

I get issues with my own functions, or some stack pointer calls, such as Uncaught (in promise) TypeError: Cannot read properties of undefined (reading '__wbindgen_add_to_stack_pointer')

FlareFlo on Feb 22, 2023

I have this exact issue, as soon as I upgrade to web_sys 0.3.61 from 0.3.60 any call to a Rust function from JavaScript results in an undefined error like:

bootstrap.js:2 Error importing `index.js`: TypeError: Cannot read properties of undefined (reading 'on_assembly_change')
    at Module.on_assembly_change (spcasm_web_bg.js:269:10)
    at eval (index.js:36:46)
    at __webpack_require__.a (bootstrap.js:357:13)
    at eval (index.js:1:21)
    at ./index.js (index_js.bootstrap.js:28:1)
    at __webpack_require__ (bootstrap.js:284:33)
    at Function.fn (bootstrap.js:592:21)

(on_assembly_change is the Rust function being called, which sort of has bindings generated, as you can see)

kleinesfilmroellchen on Feb 22, 2023