Static code analysis can find hundreds of opportunities in VBA code.
Rubberduck builds its own internal representation of the code, and then proceeds to analyze it. Each individual inspection can easily be disabled, or configured to issue inspection results at different severity levels ranging from Hint to Error.
Use the Inspection Results toolwindow to review Rubberduck’s findings, search, filter, regroup results by inspection, location, type, or severity. Each inspection result comes with a detailed description of what’s being flagged and why, so you can make an enlightened decision.
Unless configured otherwise, Rubberduck automatically runs inspections after the a parser/resolver cycle completes (regardless of whether the inspection results toolwindow is displayed or not).
For the best experience, it would be recommended to first try Rubberduck with an empty project, add a new module, and write, say, a loop that counts 1 to 10 and outputs to the debug pane - then to parse that and review the inspection results; carefully review the inspection settings, and consider disabling the inspections that irreconcilably clash with your preferences: use meaningful names alone can easily produce hundreds upon hundreds of results if you’re not that much into using vowels, or if you, say, prefix all your variable names; these inspections can be re-enabled anytime you’re ready!
This tab lists all items found in the .xml documentation assets from the latest pre-release build. To modify this content, a pull request must be merged into the [next] branch.
Warns when a user function's return value is discarded at all its call sites.
Default severity: Warning
A 'Function' procedure normally means its return value to be captured and consumed by the calling code. It's possible that not all call sites need the return value, but if the value is systematically discarded then this means the function is side-effecting, and thus should probably be a 'Sub' procedure instead.
Warns when a user function's return value is not used at a call site.
Default severity: Warning
A 'Function' procedure normally means its return value to be captured and consumed by the calling code.
Warns about host-evaluated square-bracketed expressions.
Default severity: Warning
Host-evaluated expressions should be implementable using the host application's object model. If the expression yields an object, member calls against that object are late-bound.
Flags identifiers that use [Systems] Hungarian Notation prefixes.
Default severity: Suggestion
Systems Hungarian (encoding data types in variable names) stemmed from a misunderstanding of what its inventor meant when they described that prefixes identified the "kind" of variable in a naming scheme dubbed Apps Hungarian. Modern naming conventions in all programming languages heavily discourage the use of Systems Hungarian prefixes.
Identifies Functions or Properties referenced by the TruePart(second argument) or FalsePart(third argument) of the IIf built-in function.
Default severity: Warning
All arguments of any function/procedure call are always evaluated before the function is invoked so that their respective values can be passed as parameters. Even so, the IIf Function's behavior is sometimes mis-interpreted to expect that ONLY the 'TruePart' or ONLY the 'FalsePart' expression will be evaluated based on the result of the first argument expression. Consequently, the IIf Function can be a source of unanticipated side-effects and errors if the user does not account for the fact that both the TruePart and FalsePart arguments are always evaluated.