Introduce iterable to headers helper

README.md

@@ -19,7 +19,12 @@ This middleware adds all the headers passed into the constructor to the response
 # Usage
 
 ```php
-$server = new \React\Http\HttpServer([
+use React\Http\HttpServer;
+use WyriHaximus\React\Http\Middleware\Header;
+use WyriHaximus\React\Http\Middleware\WithHeadersMiddleware;
+use WyriHaximus\React\Http\Middleware\WithRandomHeadersMiddleware;
+
+$server = new HttpServer([
     /** Other middleware */
     new WithHeadersMiddleware(
         'X-Powered-By' => 'wyrihaximus.net (11.0.33)',
@@ -39,21 +44,29 @@ Combined with [`wyrihaximus-net/x-headers`](https://github.com/WyriHaximusNet/ph
 set of Nerdy headers:
 
 ```php
-$server = new \React\Http\HttpServer([
+use React\Http\HttpServer;
+use WyriHaximus\React\Http\Middleware\Headers;
+use WyriHaximus\React\Http\Middleware\WithRandomHeadersMiddleware;
+use WyriHaximusNet\XHeaders;
+
+$server = new HttpServer([
     /** Other middleware */
     new WithRandomHeadersMiddleware(
         1,
-        ceil(count(Headers::HEADERS) / 4), // Add up to 25% of the list to it
-        ...(static function (array $headers): iterable {
-            foreach ($headers as $key => $value) {
-                yield new Header($key, $value);
-            }
-        })(Headers::HEADERS),
+        ceil(count(XHeaders\Headers::HEADERS) / 4), // Add up to 25% of the list to it
+        ...Headers::fromIterable(XHeaders\Headers::HEADERS),
     ),
     /** Other middleware */
 ]);
 ```
 
+This uses the `Headers` helper that can transform key value iterables like the following to an iterable with `Header` objects:
+```php
+[
+    'X-Header' => 'contents',
+]
+```
+
 # License
 
 The MIT License (MIT)

src/Headers.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WyriHaximus\React\Http\Middleware;
+
+final readonly class Headers
+{
+    /**
+     * @param iterable<string, string> $headers
+     *
+     * @return iterable<Header>
+     */
+    public static function fromIterable(iterable $headers): iterable
+    {
+        foreach ($headers as $header => $contents) {
+            yield new Header($header, $contents);
+        }
+    }
+}

tests/HeadersTest.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WyriHaximus\React\Tests\Http\Middleware;
+
+use WyriHaximus\AsyncTestUtilities\AsyncTestCase;
+use WyriHaximus\React\Http\Middleware\Headers;
+
+final class HeadersTest extends AsyncTestCase
+{
+    /**
+     * @param iterable<string, string> $headers
+     *
+     * @test
+     * @dataProvider provideHeaderIterables
+     */
+    public function fromIterable(iterable $headers): void
+    {
+        $headerObjects = [...Headers::fromIterable($headers)];
+
+        self::assertCount(2, $headerObjects);
+
+        self::assertSame('X-A', $headerObjects[0]->header);
+        self::assertSame('a', $headerObjects[0]->contents);
+
+        self::assertSame('X-B', $headerObjects[1]->header);
+        self::assertSame('b', $headerObjects[1]->contents);
+    }
+
+    /** @return iterable<array<iterable<string, string>>> */
+    public static function provideHeaderIterables(): iterable
+    {
+        $headers = [
+            'X-A' => 'a',
+            'X-B' => 'b',
+        ];
+
+        yield [$headers];
+
+        yield [
+            (static fn (): iterable => yield from $headers)(),
+        ];
+    }
+}