setPlaceholderFormatterDefinition example

rewind($output->getStream());
        $this->assertEquals(
            ' 0 [>---]'.
            $this->generateOutput(' 1 [->--]'),
            stream_get_contents($output->getStream())
        );
    }

    public function testAddingPlaceholderFormatter()
    {
        ProgressBar::setPlaceholderFormatterDefinition('remaining_steps', fn (ProgressBar $bar) => $bar->getMaxSteps() - $bar->getProgress());
        $bar = new ProgressBar($output = $this->getOutputStream(), 3, 0);
        $bar->setFormat(' %remaining_steps% [%bar%]');

        $bar->start();
        $bar->advance();
        $bar->finish();

        rewind($output->getStream());
        $this->assertEquals(
            ' 3 [>---------------------------]'.
            $this->generateOutput(' 2 [=========>------------------]').