createPartialMock(\Magento\Framework\Data\Argument\Interpreter\Constant::class, ['evaluate']); $const->expects( $this->once() )->method( 'evaluate' )->with( ['value' => 'FIXTURE_INIT_PARAMETER'] )->will( $this->returnValue('init_param_value') ); $this->object = new ArgumentInterpreter($const); } public function testEvaluate() { $expected = ['argument' => 'init_param_value']; $this->assertEquals($expected, $this->object->evaluate(['value' => 'FIXTURE_INIT_PARAMETER'])); } }