- Current version: SonarQube Server / Community Build 8.9.1
- Deployed via docker
Currently, I have encountered the problem of null pointer false positives. After searching, I found a way to customize the whitelist (S2259: Null pointers should not be dereferenced - #2 by Michael), but I don’t understand some of the rules, which prevents me from writing custom rules.
For example, the following rules:
{
"signature": "org.springframework.util.CollectionUtils#isEmpty(Ljava/util/Collection;)Z",
"varArgs": false,
"declaredExceptions": [],
"yields": [
{
"parametersConstraints": [
[]
],
"resultIndex": -1,
"resultConstraint": [
"TRUE",
"NOT_NULL"
]
},
{
"parametersConstraints": [
["NOT_NULL"]
],
"resultIndex": -1,
"resultConstraint": [
"FALSE",
"NOT_NULL"
]
}
]
},
My questions are as follows:
- Why is the return value true and not null when the parameter has no constraints?
According to my understanding, when the parameter is not constrained, if an empty collection is passed, the return value should be true, and if a non-empty collection is passed, the return value should return false. - Why is the return value false and not null when the parameter is not null.
When the parameter is not null, if an empty collection is passed, the return value should be true, and if a non-empty collection is passed, the return value should return false.
Similar rules include:
{
"signature": "java.lang.Class#isInstance(Ljava/lang/Object;)Z",
"varArgs": false,
"declaredExceptions": [],
"yields": [
{
"parametersConstraints": [
["NOT_NULL"]
],
"resultIndex": -1,
"resultConstraint": ["TRUE"]
},
{
"parametersConstraints": [
[]
],
"resultIndex": -1,
"resultConstraint": ["FALSE"]
}
]
},
My questions are as follows:
- Why is the return value true when the parameter is not not null
- Why is the return value false when the parameter has no constraints