Add Buffered Console Output (#36404)

* add buffered console output

* Apply fixes from StyleCI (#36403)

* change visibility

src/Illuminate/Console/Application.php

@@ -19,7 +19,6 @@
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Input\StringInput;
 use Symfony\Component\Console\Output\BufferedOutput;
-use Symfony\Component\Console\Output\ConsoleOutput;
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Process\PhpExecutableFinder;
 
@@ -86,7 +85,7 @@ public function run(InputInterface $input = null, OutputInterface $output = null
 
         $this->events->dispatch(
             new CommandStarting(
-                $commandName, $input, $output = $output ?: new ConsoleOutput
+                $commandName, $input, $output = $output ?: new BufferedConsoleOutput
             )
         );
 

src/Illuminate/Console/BufferedConsoleOutput.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Illuminate\Console;
+
+use Symfony\Component\Console\Output\ConsoleOutput;
+
+class BufferedConsoleOutput extends ConsoleOutput
+{
+    /**
+     * The current buffer.
+     *
+     * @var string
+     */
+    protected $buffer = '';
+
+    /**
+     * Empties the buffer and returns its content.
+     *
+     * @return string
+     */
+    public function fetch()
+    {
+        return tap($this->buffer, function () {
+            $this->buffer = '';
+        });
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doWrite(string $message, bool $newline)
+    {
+        $this->buffer .= $message;
+
+        if ($newline) {
+            $this->buffer .= \PHP_EOL;
+        }
+
+        return parent::doWrite($message, $newline);
+    }
+}