mangled exports breaks with destructuring assignment of JSON imports

[ikydd-bbc]

Bug report

What is the current behavior?

As of 5.90.2 (including 5.91.0), destructuring assignment on a JSON import does not work because the property names have been changed (using default settings). Setting optimization.mangleExports to false fixes this, but it worked fine in 5.90.1 and it works fine accessing properties with dot notation in 5.90.2+.

Essentially the following:

import data from './data.json';

// this works ...
console.log(data.foo.bar)

// ...but this does not
const { bar } = data.foo;

If the current behavior is a bug, please provide the steps to reproduce.

https://github.com/ikydd-bbc/spike-webpack-minify-bug

What is the expected behavior?

Destructuring of JSON imports should work as they did previously in 5.90.1. We should be able to import a JSON file using the default export and then use destructuring assignment to pick out whatever properties we choose.

Other relevant information:
webpack version: 5.90.2 +
Node.js version: 18.19.0
Operating System: OSX
Additional tools:

[alexander-akait]

Thank you for the issue, do you want to send a pr?

[ikydd-bbc]

Thank you for the issue, do you want to send a pr?

Unfortunately I have no experience working with webpack internals or the details of project goals, so while I might be curious and have a dig to see what's what I couldn't commit to trying to fix this.

[alexander-akait]

/cc @ahabhgk What do you think? I don't like named export with JSON at all, because it volates a spec - there is no named export with JSON files, only default (should we output a warning on it? with futureDefaults: true), maybe we should disable mangle at all for JSON modules?

[ahabhgk]

I think there is already have a warning for named export with JSON

webpack/lib/json/JsonParser.js

Lines 62 to 63 in 7090328

	buildMeta.defaultObject =
	typeof data === "object" ? "redirect-warn" : false;

What about disable named export with JSON in next major and when futureDefaults: true?

I will take a look and try to fix this bug in the next few days

[alexander-akait]

@ikydd-bbc Just intresting, why you used named export for JSON? Legacy code?

[alopix]

@alexander-akait
The use case shown is not really a named export from JSON though, is it?
It uses a default import and then destructures the already imported default.

import data from './data.json';

// this works ...
console.log(data.foo.bar)

// ...but this does not
const { bar } = data.foo;

[alexander-akait]

@alopix Oh, I see, my mistake, sometimes the eyes are wrong 😄 We will look at this soon