function testIsValidNotRequiredField()
 {
     $f = new Tracker_FormElement_Field_ArtifactLinkTestVersion();
     $f->setReturnValue('isRequired', false);
     $rai = new MockTracker_Valid_Rule_ArtifactId();
     $f->setReturnReference('getRuleArtifactId', $rai);
     $a = new MockTracker_Artifact();
     $this->assertTrue($f->isValid($a, array('new_values' => '')));
     $this->assertTrue($f->isValid($a, null));
 }
 function testIsValid_AddsErrorIfARequiredFieldValueIsAnEmptyString()
 {
     $f = new Tracker_FormElement_Field_ArtifactLinkTestVersion();
     $f->setReturnValue('isRequired', true);
     $a = new MockTracker_Artifact();
     $a->setReturnValue('getLastChangeset', false);
     $this->assertFalse($f->isValid($a, ''));
     $this->assertTrue($f->hasErrors());
 }