PHPUnit : test that a function is called only once - php

Question

With PHPUnit, I want to test that a function is called only once in Mocked Class. I tested several cases to be sure to understand excepts() :
functionInMock is not executed (Ok, expected result : no error) :
$myMock
->expects($this->never())
->method('functionInMock')
;
functionInMock is executed 1 times (Ok, expected result : no error) :
$myMock
->expects($this->once())
->method('functionInMock')
;
functionInMock is executed 2 times (Ok, expected result : error) :
$myMock
->expects($this->once())
->method('functionInMock')
;
functionInMock is executed 1 time :
$myMock
->expects($this->exactly(2))
->method('functionInMock')
;
or
$myMock
->expects($this->exactly(999))
->method('functionInMock')
;
Why don't I have an error in this last case ? The test passes without reporting an error.

Answer 1

I am no sure why you have unexpected behaviour but this example works fine
<?php
// Lets name it 'SampleTest.php
declare(strict_types=1);
use PHPUnit\Framework\TestCase;
class SampleTest extends TestCase
{
public function testSample(): void
{
$myMock = $this
->getMockBuilder(Sample::class)
->addMethods(['functionInMock'])
->getMock();
$myMock
->expects($this->exactly(2))
->method('functionInMock');
$myMock->functionInMock();
}
}
class Sample
{
public function function2InMock(): void
{
}
}
Execution
$ phpunit SampleTest.php
PHPUnit 9.1.1 by Sebastian Bergmann and contributors.
F 1 / 1 (100%)
Time: 125 ms, Memory: 6.00 MB
There was 1 failure:
1) SampleTest::testSample
Expectation failed for method name is "functionInMock" when invoked 2 time(s).
Method was expected to be called 2 times, actually called 1 times.
FAILURES!
Tests: 1, Assertions: 1, Failures: 1.