Mock or Stub a method in a php parent class - php

Question

I am testing a class in phpunit, but I am not mocking it, the class is like that:
class MyClass extends ParentClass
{
public function doSomething($param)
{
//do some stuff
$someValue = $this->anotherMethod(); //this method is defined in the parent class
//do some other stuff with $someValue
return $finalValue;
}
}
in the test class I am doing like this
public function testDoSomething($param)
{
$myclass = new MyClass();
//here I need to control the value of $someValue, as it affects the final value returned
$res = $myClass->doSomething();
$this->assertEqual('sonething', res);
}
so my question is How can I control the value returned from anotherMethod method? I'd prefer to mock it so it does not call other methods in it

Answer 1

You could partially mock your class and instrument the methods that you do not want to test, as the following example:
public function testDoSomething()
{
/** #var \App\Models\MyClass $classUnderTest */
$classUnderTest = $this->getMockBuilder(\App\Models\MyClass::class)
->onlyMethods(['anotherMethod'])
->getMock();
$classUnderTest->expects($this->once())
->method('anotherMethod')
->willReturn('mocked-value');
$this->assertEquals("from-test mocked-value", $classUnderTest->doSomething("from-test"));
}
with the following sources:
ParentClass
class ParentClass
{
public function anotherMethod() {
return "parent-value";
}
}
and MyClass
class MyClass extends ParentClass
{
public function doSomething($param)
{
//do some stuff
$someValue = $this->anotherMethod(); //this method is defined in the parent class
//do some other stuff with $someValue
$finalValue = $param . ' '. $someValue;
return $finalValue;
}
}