hcl: More helpful error messages in Index and GetAttr #474
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When we first implemented these helpers we tried to anticipate a few situations that seemed likely to come up and implement specialized error messages for them, but in the intervening years we've seen a number of other situations crop up with some regularity. Given that, I've added a few more specialized error message cases to both of these functions, so we'll return the most generic error messages in fewer situations. Because hcl.Index and hcl.GetAttr are quite general functions used for lots of different application-specific purposes alongside their part in the implementation of the index and attribute access operators, I've intentionally kept these messages quite vague in the suggestions they make, which does mean that unfortunately users will probably need to do some further research to find a suitable resolution to these messages. Hopefully the extra context at least gives the user a better hook for that further research. Later we could consider putting some pre-checks in the actual operator implementations that would catch some of these prior to calling the generic functions and return a more directly-prescriptive error message which assumes we're in an expression evaluation context, but I'd like to see how these new messages are received in practice first, to see if that additional complexity would be warranted.
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When we first implemented these helpers we tried to anticipate a few situations that seemed likely to come up and implement specialized error messages for them, but in the intervening years we've seen a number of other situations crop up with some regularity.
Given that, I've added a few more specialized error message cases to both of these functions, so we'll return the most generic error messages in fewer situations.
Because
hcl.Indexandhcl.GetAttrare quite general functions used for lots of different application-specific purposes alongside their part in the implementation of the index and attribute access operators, I've intentionally kept these messages quite vague in the suggestions they make, which does mean that unfortunately users will probably need to do some further research to find a suitable resolution to these messages. Hopefully the extra context at least gives the user a better hook for that further research.Later we could consider putting some pre-checks in the actual operator implementations that would catch some of these prior to calling the generic functions and return a more directly-prescriptive error message which assumes we're in an expression evaluation context, but I'd like to see how these new messages are received in practice first, to see if that additional complexity would be warranted.