Object.prototype conflict with sharp module!

[Nevro]

Sample code:

import Sharp from 'sharp';

Object.prototype.testProtoFunc = function () {
	//code
	return this;
};

const { data, info } = await Sharp('./image.png').raw().toBuffer({
	resolveWithObject: true
});

Output:

/home/user/node/node_modules/sharp/lib/output.js:1187
        sharp.pipeline(this.options, (err, data, info) => {
              ^

TypeError: A string was expected
    at /home/user/node/node_modules/sharp/lib/output.js:1187:15
    at new Promise (<anonymous>)
    at Sharp._pipeline (/home/user/node/node_modules/sharp/lib/output.js:1186:14)
    at Sharp.toBuffer (/home/user/node/node_modules/sharp/lib/output.js:146:15)
    at file:///home/user/node/src/base16.js:8:60
    at ModuleJob.run (node:internal/modules/esm/module_job:198:25)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:409:24)
    at async loadESM (node:internal/process/esm_loader:85:5)
    at async handleMainPromise (node:internal/modules/run_main:61:12)

Node.js v18.5.0
sharp 0.30.7

This is definitely not expected behavior for module!

[lovell]

The problem occurs here when parsing an Object containing EXIF metadata:

sharp/src/pipeline.cc

Lines 1496 to 1500 in e40a881

	Napi::Array mdStrKeys = mdStrs.GetPropertyNames();
	for (unsigned int i = 0; i < mdStrKeys.Length(); i++) {
	std::string k = sharp::AttrAsStr(mdStrKeys, i);
	baton->withMetadataStrs.insert(std::make_pair(k, sharp::AttrAsStr(mdStrs, k)));
	}

The existing logic uses GetPropertyNames but doesn't filter these to ensure they are "owned" by the object, thus will also try to use any properties inherited from the Object prototype.

Commit c295f06 wraps this logic in a HasOwnProperty check. This will be in v0.31.0, thanks for reporting.

[lovell]

Re-opening until the fix is published (to allow discoverability for others who might run into the same problem).

[lovell]

v0.31.0 now available, thanks for reporting.