Add --http-headers CLI option for specifying custom HTTP response header

Regarding gzip example:
- browsers need content-type: gzip and don't need transfer-encoding
- curl does not need content-type: gzip, but  needs transfer-encoding

specifying both should result in maximum compatbility

README.md

@@ -87,14 +87,17 @@ curl 127.0.0.1:1337
 
 </p>
 </details>
-<details><summary>Share application logs in realtime</summary>
+<details><summary>Tail application logs in realtime</summary>
 <p>
 
 ```bash
 # Server
 $ tail -f project/var/log/*.log|stdinho 0.0.0.0:1337
 # Client
 $ curl 127.0.0.1:1337 
+
+# Bonus: gzip transfer encoding (server)
+$ tail -f project/var/*.log|gzip -c|stdinho 0.0.0.0:1337 --http-headers='["Content-Type: text/plain", "Content-Encoding: gzip", "Transfer-Encoding: gzip"]'
 ```
 
 </p>

composer.json

@@ -12,6 +12,7 @@
     "require": {
         "php": ">=7.1",
         "ext-fileinfo": "*",
+        "ext-json": "*",
         "amphp/amp": "^2.0",
         "amphp/byte-stream": "^1.2.5",
         "amphp/socket": "^0.10",

src/Command.php

@@ -22,6 +22,10 @@ class Command extends \Symfony\Component\Console\Command\Command
      * @var bool
      */
     private $hasStdin = false;
+    /**
+     * @var string[]
+     */
+    private $customHttpHeaders = [];
 
     protected function configure(): void
     {
@@ -33,14 +37,29 @@ protected function configure(): void
                 InputOption::VALUE_REQUIRED,
                 'File path. If no stdin is provided, this is used as source. Otherwise, it is target where stdin is copied to'
             )
-            ->setDescription('Open HTTP portal to your standard input stream')
+            ->addOption(
+                'http-headers',
+                null,
+                InputOption::VALUE_REQUIRED,
+                'Custom HTTP headers to append to response (in JSON format). Eg. --http-headers=\'["Content-encoding: gzip"]\'',
+                '{}'
+            )
+            ->setDescription('Turn any STDIN/STDOUT into HTTP server')
         ;
     }
 
     protected function initialize(InputInterface $input, OutputInterface $output): void
     {
-        $this->hasStdin = ftell(STDIN) !== false && !stream_isatty(STDIN);
         $filePath = $input->getOption('file');
+        $json = $input->getOption('http-headers');
+        $this->hasStdin = ftell(STDIN) !== false && !stream_isatty(STDIN);
+        $this->customHttpHeaders = @json_decode($json, true);
+
+        if (!is_array($this->customHttpHeaders)) {
+            throw new InvalidOptionException(
+                sprintf('Invalid JSON "%s" has been used in --http-headers option', $json)
+            );
+        }
 
         if ($this->hasStdin) {
             return;
@@ -73,7 +92,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         ;
 
         $bufferHandler = asyncCoroutine($bufferer);
-        $clientHandler = asyncCoroutine(new Responder($logger, $bufferer, $output));
+        $clientHandler = asyncCoroutine(new Responder($logger, $bufferer, $output, $this->customHttpHeaders));
 
         Loop::run(function () use ($addressPort, $clientHandler, $logger, $firstSection, $bufferHandler) {
             $bufferHandler();

src/Responder.php

@@ -25,12 +25,24 @@ class Responder
      * @var ConsoleOutput
      */
     private $consoleOutput;
+    /**
+     * @var string[]
+     */
+    private $customHttpHeaders = [];
 
-    public function __construct(LoggerInterface $logger, BuffererInterface $bufferer, ConsoleOutput $consoleOutput)
-    {
+    /**
+     * @param string[] $customHttpHeaders
+     */
+    public function __construct(
+        LoggerInterface $logger,
+        BuffererInterface $bufferer,
+        ConsoleOutput $consoleOutput,
+        array $customHttpHeaders
+    ) {
         $this->logger = $logger;
         $this->bufferer = $bufferer;
         $this->consoleOutput = $consoleOutput;
+        $this->customHttpHeaders = $customHttpHeaders;
     }
 
     public function __invoke(Socket $socket): \Generator
@@ -59,7 +71,7 @@ public function __invoke(Socket $socket): \Generator
         $handle = new ResourceInputStream(fopen($this->bufferer->getFilePath(), 'rb'));
 
         try {
-            yield $socket->write(implode("\r\n", $header)."\r\n\r\n");
+            yield $socket->write(implode("\r\n", array_merge($header, $this->customHttpHeaders))."\r\n\r\n");
 
             while (true) {
                 $buffererProgress = $this->bufferer->getCurrentProgress();

tests/ResponderTest.php

@@ -21,7 +21,8 @@ public function testResponderHandlesClientAbruptDisconnect(): void
         $responder = new Responder(
             $logger = new TestLogger(),
             new ResolvedBufferer(__FILE__),
-            $this->createMock(ConsoleOutput::class)
+            $this->createMock(ConsoleOutput::class),
+            []
         );
 
         $socket = $this->getMockBuilder(ClientSocket::class)