Feature req: add exception white-lists to all rules

[adamcameron]

Some rules don't support exceptions. A one-off fix for UnusedLocalVariable is awaiting merging (https://github.com/phpmd/phpmd/pull/329), but I think rather than dealing on a case-by-case basis, the facility ought to be applied to all rules.

A case in point is that we need to whitelist $_ as an UnusedLocalVariable too, for the reasons cited in the original (closed) issue (https://github.com/phpmd/phpmd/issues/326), but $_ also trips the CamelCaseParameterName rule too, and that doesn't allow exceptions either. This means we need to clutter our code with @SuppressWarnings annotations, which kinda runs counter to the intent of phpmd in the first place.

I hasten to add I think this is a great tool, and it's really helped our code quality. And this is just a minor irk :-)

Cheers!

[ravage84]

Hi @adamcameron

Thank you for your feature request.

I'm not against it, though we have to think this through, first.

Could you do me a favor? Could you add a table of all rules here with three infos: Name, whether the rule already supports an execption white-list and in what way it does or in what way it should do so.

Example:

Rule Name	Supports Exceptions	How
ShortVariable	Yes	Full variable name gets ignored.

This way we can get an overview and do not rush in. 😼

[adamcameron]

Sure thing. I'm on the clock slightly today, and then out of circulation for a coupla days, but will get onto it as soon as I can.

[ravage84]

No problem. Take your time. Thanks!

[ravage84]

@adamcameron could you give me hand on this?

[adamcameron]

Ooh bugger... completely forgot about this. On the case. Sorry about the delay.

[adamcameron]

Rule Name	Supports Exceptions	How	Note
BooleanArgumentFlag	No	-	*
ElseExpression	No	-	*
IfStatementAssignment	No	-	*
StaticAccess	Yes	List of classes to ignore
CyclomaticComplexity	No	-	*
NPathComplexity	No	-	*
ExcessiveMethodLength	No	-	*
ExcessiveClassLength	No	-	*
ExcessiveParameterList	No	-	*
ExcessivePublicCount	No	-	*
TooManyFields	No	-	*
TooManyMethods	No		ignorepattern covers same functionality
TooManyPublicMethods	No		ignorepattern covers same functionality
ExcessiveClassComplexity	No	-	*
Superglobals	No	Possibly same as with static access?	**
CamelCaseClassName	No	-	*
CamelCasePropertyName	No	List of identifiers to ignore	**
CamelCaseMethodName	No	List of identifiers to ignore	**
CamelCaseParameterName	No	List of identifiers to ignore	**
CamelCaseVariableName	No	List of identifiers to ignore	**
ExitExpression	No	-	*
EvalExpression	No	-	*
GotoStatement	No	-	*
NumberOfChildren	No	-	*
DepthOfInheritance	No	-	*
CouplingBetweenObjects	No	-	Should be coupling between classes, btw
DevelopmentCodeFragment	No	-	unwanted-functions covers equivalent functionality
EmptyCatchBlock	No	-	*
ShortVariable	Yes	List of variable names to ignore
LongVariable	No	List of identifiers to ignore	**
ShortMethodName	Yes	List of method names to ignore
ConstructorWithNameAsEnclosingClass	No	-	*
ConstantNamingConventions	No	List of identifiers to ignore	(very edge-case with this one though)**
BooleanGetMethodName	No	List of identifiers to ignore	(but so edgy perhaps not worth a config rule?)**
UnusedPrivateField	No	-	*
UnusedLocalVariable	No	-	*
UnusedPrivateMethod	No	-	*
UnusedFormalParameter	No	List of identifiers to ignore	(EG: the use of _ in other languages to indicate an argument that won't be used in a callback's signature)**

* = no sensible way of having an exception list ** = there might be a business case for breaking naming standards

[ravage84]

Many thanks, @adamcameron !

So I'm cutting down your list to the relevant ones.

At first all the rules that support some kind of exceptions or vice versa, grouped by how the exceptions work.

Rule Name	How
DevelopmentCodeFragment	unwanted functions
TooManyMethods	ignore pattern
TooManyPublicMethods	ignore pattern
ShortVariable	List of variable names to ignore
ShortMethodName	List of method names to ignore
StaticAccess	List of classes to ignore

I see three ways of exceptions:

• Actual black list
• Ignore regex for white listing
• Actual white list

[ravage84]

Now to the list of rules, which could benefit from having some kind of exceptions.

Some exceptions would only make sense, if you could configure them in a case to case situation (read class/method/funcition). Just like envisioned by https://github.com/phpmd/phpmd/issues/30.

Grouped by how the exceptions work.

Rule Name	How
Superglobals	Unwanted list (current list = new default)
ExcessivePublicCount	Case by case ignore list or pattern only
TooManyFields	Case by case ignore list or pattern only
UnusedLocalVariable	Case by case ignore list only
CamelCasePropertyName	Ignore list or pattern
CamelCaseMethodName	Ignore list or pattern
CamelCaseParameterName	Ignore list or pattern
CamelCaseVariableName	Ignore list or pattern
LongVariable	Ignore list
ConstantNamingConventions	Ignore list
BooleanGetMethodName	Ignore list
UnusedFormalParameter	Ignore list

But I'm not really convinced whether all of them are really a good idea. I'd love to hear @manuelpichler's opinion about it.