Pattern: Use of invariant boolean
Issue: -
Conditional statements using a condition which cannot be anything but false
have the effect of making blocks of code non-functional. If the condition
cannot evaluate to anything but true, the conditional statement is completely
redundant, and makes the code less readable.
It is quite likely that the code does not match the programmer's intent.
Either the condition should be removed or it should be updated so that it does
not always evaluate to true or false and does not perform redundant tests.
This rule will hint to the test conflicting with the linted one.
Example of incorrect code:
// foo can't be both equal and not equal to bar in the same expression
if(foo == bar && something && foo != bar) {...}Example of incorrect code:
void compute(int foo) {
if (foo == 4) {
doSomething();
// we know foo is equal to 4 at this point, so the next condition is always false
if (foo > 4) {...}
...
}
...
}Example of incorrect code:
void compute(bool foo) {
if (foo) {
return;
}
doSomething();
// foo is always false here
if (foo){...}
...
}Example of correct code:
void nestedOK() {
if (foo == bar) {
foo = baz;
if (foo != bar) {...}
}
}Example of correct code:
void nestedOk2() {
if (foo == bar) {
return;
}
foo = baz;
if (foo == bar) {...} // OK
}Example of correct code:
void nestedOk5() {
if (foo != null) {
if (bar != null) {
return;
}
}
if (bar != null) {...} // OK
}