types(zoe): setTestJig param type optional

[erights]

closes: #XXXX
refs: #9531 (comment)

Description

The implementation of setTestJig at

agoric-sdk/packages/zoe/src/contractFacet/zcfZygote.js

Line 358 in 37ec151

setTestJig: (testFn = () => ({})) => {

treats its param as optional. The call to setTestJig at https://github.com/Agoric/documentation/blob/89a7dd53cd59b4008a36d23abdfa5665d1852336/snippets/tools/zcfTesterContract.js#L12 omits its parameter. The doc-comment on the type at

agoric-sdk/packages/zoe/src/contractFacet/types-ambient.d.ts

Line 139 in 37ec151

type SetTestJig = (testFn: () => Record<string, unknown>) => void;

explains the parameter as optional. But the type itself declares the parameter as mandatory.

This initially led me at #9531 to declare the parameter as mandatory in the new ZcfI interface guard, but that caused the failure in the documentation repo discussed at

agoric-sdk/packages/zoe/src/contractFacet/types-ambient.d.ts

Line 139 in 37ec151

type SetTestJig = (testFn: () => Record<string, unknown>) => void;

. My comment in the code there and the subsequent discussion assumes that the usage at the documentation repo is what needs to be fixed. But given this other evidence, I think the static type needs to be fixed to type that parameter as optional. #9531 would then be ok as is, only needing removal of the comment indicating something is amiss.

Security Considerations

There is an existing security concern with the existence of setTestJig at all. But this PR does not affect that security concern at all.

Scaling Considerations

none

Documentation Considerations

This PR would make the setTestJig call currently in the documentation repo correct.

Testing Considerations

This problem was initially detected when testing #9531 when the guard declared the parameter as mandatory. This does reenforce the lesson that TS types are unsound by enforced guards are sound.

Upgrade Considerations

This PR is only a static change consistent with all current usage and implementation, and so should have no upgrade considerations. However, just to minimize risk, it still makes sense to hold this back till after master is snapshot for u16.

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View logs

[turadg]

Confirmed the type and docs are correct by reviewing

agoric-sdk/packages/zoe/src/contractFacet/zcfZygote.js

Lines 358 to 363 in 37ec151

	setTestJig: (testFn = () => ({})) => {
	if (testJigSetter) {
	testJigSetter({ ...testFn(), zcf });
	}
	},
	getInstance: () => getInstanceRecHolder().getInstanceRecord().instance,

[Chris-Hibbert]

LGTM