Vega triggers override mistake when overriding O.p.hasOwnProperty by assignment

[erights]

At docs/vega-core.js line 32463 and at doc/vega.js line 45238 appears the line

  exports.hasOwnProperty = has;

This exports object inherits from Object.prototype which has a method named hasOwnProperty. Unfortunately, because of the EcmaScript Override Mistake (also here and here), in running in an environment (like SES, XS, or TC53 JavaScript for Embedded Systems) where Object.prototype is frozen, the Override Mistake will cause that assignment to fail.

From the line numbers above, it is clear these two files are generated files. However I do not understand what the actual source lines are that are translated into these generated lines, so I'm not sure what the best fix is. Two immediate possibilities:

• Have exports not inherit from Object.prototype. Depending on the role of exports in the translation, I would not be surprised if that is not feasible.
• Use defineProperty rather than assignment, such as

   Object.defineProperty(exports, 'hasOwnProperty', {
       value: has, 
       enumerable: true, 
       writable: true, 
       configurable: true 
   });

See Agoric/agoric-sdk#2373 for the consequences of this bug in the Agoric use of SES.

[erights]

See Agoric/agoric-sdk#2575

[domoritz]

I suspect the problem is in https://github.com/vega/vega/blob/master/packages/vega-util/src/hasOwnProperty.js. Do you have an idea how we can resolve the issue you are seeing?

[erights]

No, that's not the problem. There is nothing about that file that would trigger the override mistake.

My first post above #3075 (comment) explains the problem well, but complains about the wrong file. The problem is in vega-util/build/vega-util.js . Aside from that, please ask about anything unclear in the explanation in that first post.

Vega actually has three problems along these lines, for constructor, 'hasOwnPropertyandtoString`, all in the vega-util.js file. A patch which fixes all these is at
https://github.com/Agoric/agoric-sdk/blob/master/patches/vega-util%2B1.16.0.patch

[erights]

I just looked again at your sources rather than my patch. It looks like my patch is against, not a source file, but a file built from those sources. Is that correct? If so, then my first post was correct. The problem is in docs/vega-code.js and docs/vega.js .
However, both of these are huge files. Much larger than I'd expect from a source file. But the string exports.hasOwnProperty appears in your source tree in these two files and no where else. Where does this text come from?

[erights]

See #3109

[jheer]

Closed via #3109