[node-resolve]: sideEffects in project root package.json unexpectedly affects the bundled result of codes out of node_modules

[07akioni]

• Rollup Plugin Name: plugin-node-resolve
• Rollup Plugin Version: 11.0.0
• Rollup Version: 2.34.2
• Operating System (or Browser): Mas OS, Chrome
• Node Version: v10.22.0
• Link to reproduction (⚠️ read below):

https://repl.it/join/xcjdwawr-07akioni

Expected Behavior

The sideEffect field in project root package.json shouldn't affect the bundled code inside the project.

Actual Behavior

It has effects.

app-index.js → app-output.js...
created app-output.js in 101ms
var dist = { name: 'object' };

console.log(dist);

app-index.js → app-output-no-node-resolve.js...
created app-output-no-node-resolve.js in 57ms
var dist = { name: 'object' };

dist.sideEffect = true;

console.log(dist);

Additional Information

I'm building a library without side effects. However the demo site (may have some side-effects, for example css or some codes) is both placed in same the folder. Should we make codes out of node_modules follow its package.json?

[tjenkinson]

The sideEffect field in project root package.json shouldn't affect the bundled code inside the project.

This makes sense although I haven't checked the spec yet.

I think for each file we always look at the nearest package.json to determine if the file has side effects, which we probably shouldn't do for the root package. Added a currently failing test in 91a881d

[stale]

Hey folks. This issue hasn't received any traction for 60 days, so we're going to close this for housekeeping. If this is still an ongoing issue, please do consider contributing a Pull Request to resolve it. Further discussion is always welcome even with the issue closed. If anything actionable is posted in the comments, we'll consider reopening it. ⓘ