feature #28898 [Console] Add dumper (ro0NL)

This PR was squashed before being merged into the 4.3-dev branch (closes #28898).

Discussion
----------

[Console] Add dumper

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #...   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/issues/10502

This PR adds a new `Dumper` helper in the Console component. As there are 2 types of dumps

- debug purpose (e.g. `dd()`, `dump()`)
- output purpose (see #24208, #27684)

For the latter we cannot use the global system (debug) dumper, i.e. `VarDumper::dump()`, we need something tied to the current output and dependency free. Here it is:

```php
$io = new SymfonyStyle($input, $output);
$dumper = new Dumper($io);

$io->writeln($dumper([-0.5, 0, 1]));
$io->writeln($dumper(new \stdClass()));
$io->writeln($dumper(123));
$io->writeln($dumper('foo'));
$io->writeln($dumper(null));
$io->writeln($dumper(true));
```

With VarDumper comonent:

![image](https://user-images.githubusercontent.com/1047696/47069483-4cc26f80-d1ef-11e8-902e-2f9b0f040f25.png)

Without:

![image](https://user-images.githubusercontent.com/1047696/47069517-6663b700-d1ef-11e8-9328-ae1db0b83d7e.png)

> https://github.com/symfony/symfony/pull/27684#discussion_r224054237 var-dumper is not a mandatory dep of fwb, can we do without?

Now we can  :)

Commits
-------

fc7465c02c [Console] Add dumper

src/Symfony/Component/Console/Helper/Dumper.php

@@ -0,0 +1,64 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Console\Helper;
+
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\VarDumper\Cloner\ClonerInterface;
+use Symfony\Component\VarDumper\Cloner\VarCloner;
+use Symfony\Component\VarDumper\Dumper\CliDumper;
+
+/**
+ * @author Roland Franssen <franssen.roland@gmail.com>
+ */
+final class Dumper
+{
+    private $output;
+    private $dumper;
+    private $cloner;
+    private $handler;
+
+    public function __construct(OutputInterface $output, CliDumper $dumper = null, ClonerInterface $cloner = null)
+    {
+        $this->output = $output;
+        $this->dumper = $dumper;
+        $this->cloner = $cloner;
+
+        if (class_exists(CliDumper::class)) {
+            $this->handler = function ($var): string {
+                $dumper = $this->dumper ?? $this->dumper = new CliDumper(null, null, CliDumper::DUMP_LIGHT_ARRAY | CliDumper::DUMP_COMMA_SEPARATOR);
+                $dumper->setColors($this->output->isDecorated());
+
+                return rtrim($dumper->dump(($this->cloner ?? $this->cloner = new VarCloner())->cloneVar($var)->withRefHandles(false), true));
+            };
+        } else {
+            $this->handler = function ($var): string {
+                switch (true) {
+                    case null === $var:
+                        return 'null';
+                    case true === $var:
+                        return 'true';
+                    case false === $var:
+                        return 'false';
+                    case \is_string($var):
+                        return '"'.$var.'"';
+                    default:
+                        return rtrim(print_r($var, true));
+                }
+            };
+        }
+    }
+
+    public function __invoke($var): string
+    {
+        return ($this->handler)($var);
+    }
+}

src/Symfony/Component/Console/Tests/Helper/DumperNativeFallbackTest.php

@@ -0,0 +1,58 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Console\Tests\Helper;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Bridge\PhpUnit\ClassExistsMock;
+use Symfony\Component\Console\Helper\Dumper;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\VarDumper\Dumper\CliDumper;
+
+class DumperNativeFallbackTest extends TestCase
+{
+    public static function setUpBeforeClass()
+    {
+        ClassExistsMock::register(Dumper::class);
+        ClassExistsMock::withMockedClasses([
+            CliDumper::class => false,
+        ]);
+    }
+
+    public static function tearDownAfterClass()
+    {
+        ClassExistsMock::withMockedClasses([]);
+    }
+
+    /**
+     * @dataProvider provideVariables
+     */
+    public function testInvoke($variable, $primitiveString)
+    {
+        $dumper = new Dumper($this->getMockBuilder(OutputInterface::class)->getMock());
+
+        $this->assertSame($primitiveString, $dumper($variable));
+    }
+
+    public function provideVariables()
+    {
+        return [
+            [null, 'null'],
+            [true, 'true'],
+            [false, 'false'],
+            [1, '1'],
+            [-1.5, '-1.5'],
+            ['string', '"string"'],
+            [[1, '2'], "Array\n(\n    [0] => 1\n    [1] => 2\n)"],
+            [new \stdClass(), "stdClass Object\n(\n)"],
+        ];
+    }
+}

src/Symfony/Component/Console/Tests/Helper/DumperTest.php

@@ -0,0 +1,58 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Console\Tests\Helper;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Console\Helper\Dumper;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\VarDumper\Test\VarDumperTestTrait;
+
+class DumperTest extends TestCase
+{
+    use VarDumperTestTrait;
+
+    public static function setUpBeforeClass()
+    {
+        putenv('DUMP_LIGHT_ARRAY=1');
+        putenv('DUMP_COMMA_SEPARATOR=1');
+    }
+
+    public static function tearDownAfterClass()
+    {
+        putenv('DUMP_LIGHT_ARRAY');
+        putenv('DUMP_COMMA_SEPARATOR');
+    }
+
+    /**
+     * @dataProvider provideVariables
+     */
+    public function testInvoke($variable)
+    {
+        $dumper = new Dumper($this->getMockBuilder(OutputInterface::class)->getMock());
+
+        $this->assertDumpMatchesFormat($dumper($variable), $variable);
+    }
+
+    public function provideVariables()
+    {
+        return [
+            [null],
+            [true],
+            [false],
+            [1],
+            [-1.5],
+            ['string'],
+            [[1, '2']],
+            [new \stdClass()],
+        ];
+    }
+}

src/Symfony/Component/Console/composer.json

@@ -27,6 +27,7 @@
         "symfony/dependency-injection": "~3.4|~4.0",
         "symfony/lock": "~3.4|~4.0",
         "symfony/process": "~3.4|~4.0",
+        "symfony/var-dumper": "^4.3",
         "psr/log": "~1.0"
     },
     "provide": {

src/Symfony/Component/VarDumper/Test/VarDumperTestTrait.php

@@ -33,6 +33,7 @@ trait VarDumperTestTrait
     {
         $flags = getenv('DUMP_LIGHT_ARRAY') ? CliDumper::DUMP_LIGHT_ARRAY : 0;
         $flags |= getenv('DUMP_STRING_LENGTH') ? CliDumper::DUMP_STRING_LENGTH : 0;
+        $flags |= getenv('DUMP_COMMA_SEPARATOR') ? CliDumper::DUMP_COMMA_SEPARATOR : 0;
 
         $cloner = new VarCloner();
         $cloner->setMaxItems(-1);