filesystem = $this->prophesize('League\Flysystem\FilesystemInterface'); $this->actualFilesystem = $this->filesystem->reveal(); } public function testHandle() { $plugin = new ListPaths(); $this->assertEquals('listPaths', $plugin->getMethod()); $this->filesystem->listContents('dirname', true)->willReturn([ ['path' => 'dirname/path.txt'], ]); $plugin->setFilesystem($this->actualFilesystem); $output = $plugin->handle('dirname', true); $this->assertEquals(['dirname/path.txt'], $output); } }