cannot coerce detailsToken to string

[dckc]

We construct detailsToken as follows:

endo/packages/ses/src/error/assert.js

Line 72 in fb06d7d

const detailsToken = freeze({ __proto__: null });

and similarly on line 92.

Then in assert.note, we attempt to stringify it:

  if (hiddenDetails === undefined) {
    throw new Error(`unrecognized details ${detailsNote}`);
  }

On XS, this throws cannot coerce object to string. On node, likewise:

> `${{__proto__: null}}`
Thrown:
TypeError: Cannot convert object to primitive value

It seems error-prone to try to prevent stringifying detailsToken, so I suggest adding toString() methods.

context:

The moddable folks pointed this out in the course of debugging Agoric/agoric-sdk#3039; it was triggered in trackTurns:

  if (hiddenPriorError !== undefined) {
    assert.note(sendingError, X`Caused by: ${hiddenPriorError}`);
  }

[erights]

@dckc I agree with your recommendation and will do that. But reading the code, I am confused how this arose. The detailsToken constructed near lines 72 and 92 are both followed by

hiddenDetailsMap.set(detailsToken, { template, args });

We never remove it from that weakmap or store anything else in there. The line immediate prior to both occurrences of the test you show above is

  const hiddenDetails = hiddenDetailsMap.get(optDetails);

Thus, for the detailsTokens made near lines 72 and 92, if we are using the same instance of the assert module and thus the same weakmap, I don't see how hiddenDetails can ever be undefined.

If we are instantiating the assert module twice, so that one doesn't recognize the detailsToken generated by the other, that itself would be a bad problem we need to fix. Can you help me reproduce this?

[dckc]

@dckc ... We never remove it from that weakmap ... I don't see how hiddenDetails can ever be undefined. ... Can you help me reproduce this?

I'm not confident that I can, on node; as I say, this arose in the context of Agoric/agoric-sdk#3039 , which has since been diagnosed as a GC bug in XS that resulted in things getting dropped from WeakMaps.