Header parsing improvements

* Made headers public readonly in HeadersFrame
* Fetching headers by value implemented
* Initial tests for HeaderBag

src/Frame/HeadersFrame.php

@@ -2,7 +2,26 @@
 
 namespace NoccyLabs\React\Http2\Frame;
 
+use NoccyLabs\React\Http2\Header\HeaderBag;
+use NoccyLabs\React\Http2\Header\HeaderPacker;
+
 class HeadersFrame extends Frame
 {
+    static ?HeaderPacker $headerPacker = null;
+
+    public readonly HeaderBag $headers;
+
+    public function fromBinary(string $binary): void
+    {
+        if (!self::$headerPacker)
+            self::$headerPacker = new HeaderPacker();
+
+        $this->headers = self::$headerPacker->unpackHeaders($binary);
+    }
+
+    public function toBinary(): string
+    {
+        return self::$headerPacker->packHeaders($this->headers);
+    }
 }
 

src/Header/HeaderBag.php

@@ -25,7 +25,23 @@ class HeaderBag implements IteratorAggregate
 
     public function append(string $name, string $value)
     {
-        $this->headers[] = [ $name, $value ];
+        $this->headers[] = [$name, $value ];
+    }
+
+    public function getAllHeaders(): array
+    {
+        return $this->headers;
+    }
+
+    public function getHeaders(string $name): ?array
+    {
+        return array_map(fn($v) => $v[1], array_filter($this->headers, fn($v) => $v[0] == $name));
+    }
+
+    public function getHeaderLine(string $name): ?string
+    {
+        $headers = $this->getHeaders($name);
+        return array_shift($headers);
     }
 
     public function getIterator(): Traversable

tests/Header/HeaderBagTest.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace NoccyLabs\React\Http2\Header;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+
+#[CoversClass(HeaderBag::class)]
+#[CoversClass(HeaderPacker::class)]
+class HeaderBagTest extends \PHPUnit\Framework\TestCase
+{
+
+    public function testHeadersInExamplesFromRfc7541()
+    {
+        $packer = new HeaderPacker();
+
+        $in = "\x82\x86\x84\x41\x8c\xf1\xe3\xc2\xe5\xf2\x3a\x6b\xa0\xab\x90\xf4\xff";
+        $expect = new HeaderBag([
+            ':method' => 'GET',
+            ':scheme' => 'http',
+            ':path' => '/',
+            ':authority' => 'www.example.com'
+        ]);
+        $out = $packer->unpackHeaders($in);
+
+        $this->assertEquals('GET', $out->getHeaderLine(':method'));
+        $this->assertEquals('http', $out->getHeaderLine(':scheme'));
+        $this->assertEquals('/', $out->getHeaderLine(':path'));
+        $this->assertEquals('www.example.com', $out->getHeaderLine(':authority'));
+
+    }
+
+    
+}