Treeshaking and dead code

[igorskyflyer]

Hello, a very fast and very efficient bundler indeed but I am having issues with treeshaking, sorry in advance if I misunderstood the concept of treeshaking. Let me explain the issue; as all of us who use bundlers we install our 3rd-party modules and bundle them into a single file but what I'm seeing in that bundle file is a lot of dead code.

For example, let's say we have a library X that exports 2 functions and has some top-level variables (for whatever reason) which are only referenced in one of the 2 functions but I don't use that function, I use the other one - the one that doesn't reference any top-level variables.

In my project Y I set up everything and bundle the code and I see all variables + all functions from library X in the bundle file.

Note that setting sideEffects: false in the library X doesn't do anything.

Is this the expected behaviour or am I missing something? Also, I've set up a repository for you to test - if you want to - it's located at igorskyflyer/esbuild-treeshaking. I've included the dist folder too so you don't have to build anything to begin with. 😄

P.S. don't judge me by my code in the lib folder, I never use quotes - only single quotes and I don't name my variables like that!!! 😂

Thanks.

[igorskyflyer]

May be somewhat related to #1435.

[hyrious]

there's no tree shaking support for cjs code (lib/main.js) now. you should use esm (import/export).

[igorskyflyer]

there's no tree shaking support for cjs code (lib/main.js) now. you should use esm (import/export).

Ah, that makes sense, don't I feel stupid now? 😁 I'll work it out somehow with ES modules, thanks. 👍

[igorskyflyer]

there's no tree shaking support for cjs code (lib/main.js) now. you should use esm (import/export).

Ah, that makes sense, don't I feel stupid now? 😁 I'll work it out somehow with ES modules, thanks. 👍

Or not - I mean - it does work but it requires all modules to be ES modules which is almost impossible to obtain at this moment in the npm ecosystem. 😥

[Aworldc]

there's no tree shaking support for cjs code (lib/main.js) now. you should use esm (import/export).

Ah, that makes sense, don't I feel stupid now? 😁 I'll work it out somehow with ES modules, thanks. 👍

Or not - I mean - it does work but it requires all modules to be ES modules which is almost impossible to obtain at this moment in the npm ecosystem. 😥

Yeah. that's my issue. Anyone know of something that can treeshake cjs?