[pmd-devel] Custom Apex rule questions

[Caleb K. <cal...@en...>]

Hi there folks,

I am trying to implement a few more rules for the project I've emailed
about before, before we send it off to our customers. This is working with
Salesforce/Apex classes.

Here they are:



*ApexOptimizeSoqlRule*
Example:

List<Account> acct = […];
for (Account a : acct ) {

}

// add violation

-------------------------------------------

// optimized version

for (Account acct : [Select … ] ) {

}

// all good

For this rule, I was planning on looking at ASTForEachStatement nodes,
checking the children for an ASTSoqlExpression node, as well as looking at
ASTSoqlExpression nodes and checking their parents for a List<>
declaration. However, what I have is not working, so I am wondering if my
basic way of thinking about this rule is wrong, and if I should do
something else.



*ApexSingleSoqlResultRule*
Example:

Account acct = [Select Id From Account Where Name = ‘abc’ ];

// Get QueryException back if 0 or duplicate

// People try to avoid by doing:

List<Account> acct = [Select … LIMIT 1]; // bad practice to avoid dupes etc
--> add violation

if (acct.size() > 0 )

[...]


--------------------------------------------

// Best practice is:

try {
Account acct = […];
} catch (QueryException q){

}

For this rule, I am checking ASTSoqlExpression nodes. If their parent nodes
include a try/catch, no violation. Else, add violation.

I also check the ASTSoqlExpression for a LIMIT 1 since that's how people
avoid the QueryException. But, I don't quite know how to do that.

Maybe something like this?

if(node.getNode().getQuery().toLowerCase().contains("list") &&
                node.getNode().getQuery().toLowerCase().contains("limit 1"))


*ApexCommentRule*

The last two rules are related to readability. The first one looks at the
following:

   - No class or method comments => add to violation count


For this, can I just use a Java rule, like CommentRequiredRule?

*ApexReadabilityRule*

The last one follows these criteria:

   - Lines of code in a method exceed 50 => add to violation count
   - Nested if statements exceed more than 3  => add to violation count
   - Non trigger framework code  exists in triggers  => add to violation
   count


I'm not sure how to do this last one.

If you have any insight or feedback, let me know!

Thank you.

-- 
Caleb Knox

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