CodeQL language preview

1. Unused variable query

a QLDoc header, a predicate check, and a select placeholder

horizon-dark

/**
 * @name Unused variable
 * @kind problem
 * @problem.severity warning
 */
import javascript

from Variable v
where not exists(VarAccess a | a.getVariable() = v)
select v, "Unused variable $@.", v, v.getName()

atom-one-dark

/**
 * @name Unused variable
 * @kind problem
 * @problem.severity warning
 */
import javascript

from Variable v
where not exists(VarAccess a | a.getVariable() = v)
select v, "Unused variable $@.", v, v.getName()

github-dark

/**
 * @name Unused variable
 * @kind problem
 * @problem.severity warning
 */
import javascript

from Variable v
where not exists(VarAccess a | a.getVariable() = v)
select v, "Unused variable $@.", v, v.getName()

dracula

/**
 * @name Unused variable
 * @kind problem
 * @problem.severity warning
 */
import javascript

from Variable v
where not exists(VarAccess a | a.getVariable() = v)
select v, "Unused variable $@.", v, v.getName()

nord

/**
 * @name Unused variable
 * @kind problem
 * @problem.severity warning
 */
import javascript

from Variable v
where not exists(VarAccess a | a.getVariable() = v)
select v, "Unused variable $@.", v, v.getName()

github

/**
 * @name Unused variable
 * @kind problem
 * @problem.severity warning
 */
import javascript

from Variable v
where not exists(VarAccess a | a.getVariable() = v)
select v, "Unused variable $@.", v, v.getName()

2. A predicate

a reusable predicate definition

horizon-dark

predicate isEven(int x) {
  x % 2 = 0
}

atom-one-dark

predicate isEven(int x) {
  x % 2 = 0
}

github-dark

predicate isEven(int x) {
  x % 2 = 0
}

dracula

predicate isEven(int x) {
  x % 2 = 0
}

nord

predicate isEven(int x) {
  x % 2 = 0
}

github

predicate isEven(int x) {
  x % 2 = 0
}

3. Aggregations

count and exists in a where clause

horizon-dark

from Function f
where count(f.getAParameter()) > 5
select f, "Too many parameters"

atom-one-dark

from Function f
where count(f.getAParameter()) > 5
select f, "Too many parameters"

github-dark

from Function f
where count(f.getAParameter()) > 5
select f, "Too many parameters"

dracula

from Function f
where count(f.getAParameter()) > 5
select f, "Too many parameters"

nord

from Function f
where count(f.getAParameter()) > 5
select f, "Too many parameters"

github

from Function f
where count(f.getAParameter()) > 5
select f, "Too many parameters"