Added Logger.

Author: andrew-svirin

AGENTS.md

@@ -143,3 +143,16 @@ Pass `$fake = true` or `$debug = true` to `setupClient*()` to use `FakerHttpClie
 ## Notable Implementation Details
 
 - Classes marked `@internal` may change without notice.
+
+## Zero-Dependency Policy
+
+**The library must have zero external production dependencies.** This is a core design principle. Only PHP extensions are allowed in `require`.
+
+- `composer.json` `require` section may only contain `php ^8.5` and `ext-*` entries.
+- When a PSR interface is needed (e.g. PSR-3 Logger), copy it into `src/Contracts/`.
+- PSR-18 HTTP client: the library uses its own `HttpClientInterface` in `src/Contracts/` (not PSR-18).
+- PSR-3 Logger: `LoggerInterface` is defined in `src/Contracts/LoggerInterface.php`.
+
+## Logging
+
+The `EbicsClient` uses `LoggerInterface` (PSR-3 compatible) for logging transaction steps, HTTP requests, errors, and other important events.

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## 3.1
 
+* Added Logger.
 * Safety & Stability & Documentation improvements.
 
 ## 3.0

src/Builders/Request/BodyBuilder.php

@@ -16,8 +16,8 @@
  */
 abstract class BodyBuilder extends XmlBuilder
 {
-    protected ZipService $zipService;
-    protected CryptService $cryptService;
+    protected readonly ZipService $zipService;
+    protected readonly CryptService $cryptService;
     protected DOMElement $instance;
 
     public function __construct(ZipService $zipService, CryptService $cryptService, DOMDocument $dom)

src/Builders/Request/DataEncryptionInfoBuilder.php

@@ -17,7 +17,7 @@
 final class DataEncryptionInfoBuilder extends XmlBuilder
 {
     private DOMElement $instance;
-    private CryptService $cryptService;
+    private readonly CryptService $cryptService;
 
     public function __construct(CryptService $cryptService, DOMDocument $dom)
     {

src/Builders/Request/DataTransferBuilder.php

@@ -18,8 +18,8 @@
 abstract class DataTransferBuilder extends XmlBuilder
 {
     protected DOMElement $instance;
-    protected ZipService $zipService;
-    protected CryptService $cryptService;
+    protected readonly ZipService $zipService;
+    protected readonly CryptService $cryptService;
 
     public function __construct(ZipService $zipService, CryptService $cryptService, DOMDocument $dom)
     {

src/Builders/Request/HeaderBuilder.php

@@ -15,7 +15,7 @@
  */
 abstract class HeaderBuilder extends XmlBuilder
 {
-    protected CryptService $cryptService;
+    protected readonly CryptService $cryptService;
     protected DOMElement $instance;
 
     public function __construct(CryptService $cryptService, DOMDocument $dom)

src/Builders/Request/RequestBuilder.php

@@ -15,15 +15,13 @@
  */
 final class RequestBuilder
 {
-    private AuthSignatureHandler $authSignatureHandler;
     private ?Request $instance;
     private RootBuilder $rootBuilder;
-    private SchemaValidator $validator;
 
-    public function __construct(AuthSignatureHandler $authSignatureHandler, SchemaValidator $validator)
-    {
-        $this->authSignatureHandler = $authSignatureHandler;
-        $this->validator = $validator;
+    public function __construct(
+        private readonly AuthSignatureHandler $authSignatureHandler,
+        private readonly SchemaValidator $validator
+    ) {
     }
 
     public function createInstance(Closure $callback): RequestBuilder

src/Builders/Request/RootBuilder.php

@@ -30,8 +30,8 @@ abstract class RootBuilder extends XmlBuilder
         self::EBICS_HEV => false,
     ];
 
-    protected ZipService $zipService;
-    protected CryptService $cryptService;
+    protected readonly ZipService $zipService;
+    protected readonly CryptService $cryptService;
     protected DOMElement $instance;
 
     public function __construct(

src/Builders/Request/StaticBuilder.php

@@ -20,7 +20,7 @@ abstract class StaticBuilder extends XmlBuilder
     const SECURITY_MEDIUM_0200 = '0200';
 
     protected DOMElement $instance;
-    protected CryptService $cryptService;
+    protected readonly CryptService $cryptService;
 
     public function __construct(CryptService $cryptService, DOMDocument $dom)
     {

src/Builders/Request/XmlBuilder.php

@@ -13,11 +13,8 @@
  */
 abstract class XmlBuilder
 {
-    protected DOMDocument $dom;
-
-    public function __construct(DOMDocument $dom)
+    public function __construct(protected readonly DOMDocument $dom)
     {
-        $this->dom = $dom;
     }
 
     /**