PHPUnit "Mocked method does not exist." when using $mock->expects($this->at(...))

The issue ended up being with how I understood the "at" matcher to work. Also, my example was not verbatim how it is in my unit test. I thought the "at" matcher counter worked on a per query basis, where it really works on a per object instance basis.

Example:

class MyClass {

    public function exists($foo) {
        return false;
    }

    public function find($foo) {
        return $foo;
    }
}

Incorrect:

class MyTest extends PHPUnit_Framework_TestCase
{

    public function testThis()
    {
        $mock = $this->getMock('MyClass');
        $mock->expects($this->at(0))
             ->method('exists')
             ->with($this->equalTo('foo'))
             ->will($this->returnValue(true));

        $mock->expects($this->at(0))
             ->method('find')
             ->with($this->equalTo('foo'))
             ->will($this->returnValue('foo'));

        $mock->expects($this->at(1))
             ->method('exists')
             ->with($this->equalTo('bar'))
             ->will($this->returnValue(false));

        $this->assertTrue($mock->exists("foo"));
        $this->assertEquals('foo', $mock->find('foo'));
        $this->assertFalse($mock->exists("bar"));
    }

}

Correct:

class MyTest extends PHPUnit_Framework_TestCase
{

    public function testThis()
    {
        $mock = $this->getMock('MyClass');
        $mock->expects($this->at(0))
             ->method('exists')
             ->with($this->equalTo('foo'))
             ->will($this->returnValue(true));

        $mock->expects($this->at(1))
             ->method('find')
             ->with($this->equalTo('foo'))
             ->will($this->returnValue('foo'));

        $mock->expects($this->at(2))
             ->method('exists')
             ->with($this->equalTo('bar'))
             ->will($this->returnValue(false));

        $this->assertTrue($mock->exists("foo"));
        $this->assertEquals('foo', $mock->find('foo'));
        $this->assertFalse($mock->exists("bar"));
    }

}

FYI, Not sure if its related, but I encountered the same thing, but not with the $this->at() method, for me it was the $this->never() method.

This raised the error

$mock->expects($this->never())
    ->method('exists')
    ->with('arg');

This fixed the error

$mock->expects($this->never())
    ->method('exists');  

It did the same thing when using the $this->exactly(0) method.

Hope this help someone.

Try changing $this->at(1) to $this->at(2)