Request's Header allows string[] only (#491)

* Request's Header allows string[] only

* Deactivate psalm impossible null argument

* Fix possible null value

Author: jderusse

src/AbstractApi.php

@@ -103,7 +103,7 @@ final protected function getResponse(Request $request, ?RequestContext $context
 
         $length = $request->getBody()->length();
         if (null !== $length && !$request->hasHeader('content-length')) {
-            $request->setHeader('content-length', $length);
+            $request->setHeader('content-length', (string) $length);
         }
 
         // Some servers (like testing Docker Images) does not supports `Transfer-Encoding: chunked` requests.

src/Request.php

@@ -29,15 +29,16 @@ class Request
     private $parsed;
 
     /**
-     * @param string[]|string[][] $headers
+     * @param string[] $query
+     * @param string[] $headers
      */
     public function __construct(string $method, string $uri, array $query, array $headers, RequestStream $body)
     {
         $this->method = $method;
         $this->uri = $uri;
         $this->headers = [];
         foreach ($headers as $key => $value) {
-            $this->headers[\strtolower($key)] = $value;
+            $this->headers[\strtolower($key)] = (string) $value;
         }
         $this->body = $body;
         $this->query = $query;
@@ -64,7 +65,7 @@ public function hasHeader($name): bool
         return \array_key_exists(strtolower($name), $this->headers);
     }
 
-    public function setHeader($name, $value): void
+    public function setHeader($name, ?string $value): void
     {
         $this->headers[strtolower($name)] = $value;
     }
@@ -74,10 +75,7 @@ public function getHeaders(): array
         return $this->headers;
     }
 
-    /**
-     * @return string|string[]
-     */
-    public function getHeader(string $name)
+    public function getHeader(string $name): ?string
     {
         return $this->headers[strtolower($name)] ?? null;
     }

src/Signer/SignerV4.php

@@ -83,7 +83,8 @@ public function sign(Request $request, Credentials $credentials, RequestContext
     protected function buildBodyDigest(Request $request, bool $isPresign): string
     {
         if ($request->hasHeader('x-amz-content-sha256')) {
-            $hash = ((array) $request->getHeader('x-amz-content-sha256'))[0];
+            /** @var string $hash */
+            $hash = $request->getHeader('x-amz-content-sha256');
         } else {
             $body = $request->getBody();
             if ($body instanceof ReadOnceResultStream) {
@@ -257,7 +258,7 @@ private function convertBodyToStream(Request $request, \DateTimeImmutable $now,
     {
         $body = $request->getBody();
         if ($request->hasHeader('content-length')) {
-            $contentLength = (int) ((array) $request->getHeader('content-length'))[0];
+            $contentLength = (int) $request->getHeader('content-length');
         } else {
             $contentLength = $body->length();
         }
@@ -278,14 +279,14 @@ private function convertBodyToStream(Request $request, \DateTimeImmutable $now,
 
         // Convert the body into a chunked stream
         $request->setHeader('content-encoding', 'aws-chunked');
-        $request->setHeader('x-amz-decoded-content-length', $contentLength);
+        $request->setHeader('x-amz-decoded-content-length', (string) $contentLength);
         $request->setHeader('x-amz-content-sha256', 'STREAMING-' . self::ALGORITHM_CHUNK);
 
         // Compute size of content + metadata used sign each Chunk
         $chunkCount = (int) ceil($contentLength / self::CHUNK_SIZE);
         $fullChunkCount = $chunkCount * self::CHUNK_SIZE === $contentLength ? $chunkCount : ($chunkCount - 1);
         $metaLength = \strlen(";chunk-signature=\r\n\r\n") + 64;
-        $request->setHeader('content-length', $contentLength + $fullChunkCount * ($metaLength + \strlen((string) dechex(self::CHUNK_SIZE))) + ($chunkCount - $fullChunkCount) * ($metaLength + \strlen((string) dechex($contentLength % self::CHUNK_SIZE))) + $metaLength + 1);
+        $request->setHeader('content-length', (string) ($contentLength + $fullChunkCount * ($metaLength + \strlen((string) dechex(self::CHUNK_SIZE))) + ($chunkCount - $fullChunkCount) * ($metaLength + \strlen((string) dechex($contentLength % self::CHUNK_SIZE))) + $metaLength + 1));
 
         $body = IterableStream::create((function (RequestStream $body) use ($now, $credentialString, $signingKey, &$signature): iterable {
             foreach (FixedSizeStream::create($body, self::CHUNK_SIZE) as $chunk) {