fix(sdk/vm): improve MsgCall panic error message for wrong number of args

[jefft0]

If a realm function Call has too many arguments, VMKeeper Call panics with an uninformative index error message like "index out of range [1] with length 1" when it is checking the arguments. One of our devs lost time trying to figure this out, as would other devs presumably.

This PR adds explicit checks for number of arguments with informative panic messages like "not enough arguments in call to Echo" or "too many arguments in call to Echo" . (These are the same errors as the Go compiler.)

(I couldn't find an existing issue for this. If you already have other plans to improve this error message, then you can close this PR.)

Contributors' checklist...

• Added new tests, or not needed, or not feasible
• Provided an example (e.g. screenshot) to aid review or the PR is self-explanatory
• Updated the official documentation not needed
• No breaking changes were made, or a BREAKING CHANGE: xxx message was included in the description
• Added references to related issues and PRs
• Provided any useful hints for running manual tests
• Added new benchmarks to generated graphs, if any. More info here.

[thehowl]

greatly appreciated!

I think we can be more explicit about how many args we want, so here is a better version imo.

(note: I wondered what happened if we had a variadic function; turns out we don't support these in maketx call currently, though it would be nice if we did :) going to make an issue)

[jefft0]

I think we can be more explicit about how many args we want, so here is a better version imo.

Looks good. I clicked "Add suggestion to batch".

I wondered what happened if we had a variadic function

You probably saw that this check for the number of arguments comes just after excluding variadics.

gno/gno.land/pkg/sdk/vm/keeper.go

Line 241 in 12b4b45

panic("variadic calls not yet supported")

[jefft0]

I also updated the test to use the revised expected panic message.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (7382d7c) 55.79% compared to head (52085e4) 56.05%.
Report is 6 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1610      +/-   ##
==========================================
+ Coverage   55.79%   56.05%   +0.26%     
==========================================
  Files         436      438       +2     
  Lines       66168    66720     +552     
==========================================
+ Hits        36917    37400     +483     
- Misses      26360    26420      +60     
- Partials     2891     2900       +9     

Flag	Coverage Δ
go-1.21.x	∅ <ø> (∅)
misc	∅ <ø> (∅)
misc-_test.genstd	∅ <ø> (∅)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.