hcldec: A test case for attributes set to cty.DynamicVal with refinements #626
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…ents This test case is here to anticipate a _possible_ bug that isn't actually buggy in the current implementation: if an attribute spec is given a non-dynamic type constraint and then refined based on that type constraint then the hcldec implementation must perform the type conversion first and only then attempt to add the refinements. Another possible variation here would be for the attribute spec to have a dynamic type constraint (cty.DynamicPseudoType) and then try to refine its result. That case isn't tested here because that's always an implementation error in the calling application: RefineValueSpec must be used only in ways that are valid for the full range of types that the nested spec could produce, and there are no refinements that are valid for the full range of cty.DynamicPseudoType. That situation can and will panic at runtime, alerting the application developer that they've used hcldec incorrectly. There is no way for end-user input to cause this panic if the calling application is written correctly. This doesn't actually change the system behavior. It's a regression test to catch possible regressions under future maintenance.
kmoe
approved these changes
Aug 30, 2023
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This test case is here to anticipate a possible bug that isn't actually buggy in the current implementation: if an attribute spec is given a non-dynamic type constraint and then refined based on that type constraint then the hcldec implementation must perform the type conversion first and only then attempt to add the refinements.
Another possible variation here would be for the attribute spec to have a dynamic type constraint (
cty.DynamicPseudoType) and then try to refine its result. That case isn't tested here because that's always an implementation error in the calling application:RefineValueSpecmust be used only in ways that are valid for the full range of types that the nested spec could produce, and there are no refinements that are valid for the full range ofcty.DynamicPseudoType--cty.DynamicValis unrefineable. That situation can and will panic at runtime, alerting the application developer that they've used hcldec incorrectly. There is no way for end-user input to cause this panic if the calling application is written correctly.This doesn't actually change the system behavior. It's a regression test to catch possible regressions under future maintenance. I added this test case after investigating a suspicion raised in #625, in which I found that the system currently behaves correctly in this case but that there was no test case verifying that to be true.
(The key difference between this and the bug in #625 is that
typeexprallows specifying type constraints as part of the end-user input -- the type constraint itself is decided dynamically at runtime -- whereas when usinghcldecthe spec should either be fixed at compile time as part of the application or generated from user input in some other place. In the latter case it's the calling application's responsibility to ensure that the dynamically-generated type constraint is valid before using it withhcldec.)