chore: Improve service binding logic (#636)

* improve service binding logic

* improve tests

* release notes

Author: Jonas-Isr

core/src/main/java/com/sap/ai/sdk/core/AiCoreServiceKeyAccessor.java

@@ -81,6 +81,11 @@ static ServiceBinding createServiceBinding(@Nonnull final String serviceKey)
           new AiCoreCredentialsInvalidException("Missing clientid in service key"));
     }
 
+    if (credentials.get("clientsecret") != null && credentials.get("credential-type") == null) {
+      // add missing "credential-type: binding-secret"
+      credentials.put("credential-type", "binding-secret");
+    }
+
     return new DefaultServiceBindingBuilder()
         .withServiceIdentifier(ServiceIdentifier.AI_CORE)
         .withCredentials(credentials)

core/src/test/java/com/sap/ai/sdk/core/AiCoreServiceKeyAccessorTest.java

@@ -55,4 +55,32 @@ void testMalformedDotenv() {
     assertThatThrownBy(accessor::getServiceBindings)
         .isInstanceOf(ServiceBindingAccessException.class);
   }
+
+  @Test
+  void testServiceBindingCreation() {
+    var serviceKeyWithoutCredentialType =
+        """
+        {
+          "clientid": "",
+          "clientsecret": ""
+        }
+        """;
+    var binding1 = AiCoreServiceKeyAccessor.createServiceBinding(serviceKeyWithoutCredentialType);
+    assertThat(binding1.getCredentials().containsKey("credential-type"))
+        .describedAs("The missing 'credential-type' should have automatically been added")
+        .isTrue();
+    var serviceKeyWithCredentialType =
+        """
+        {
+          "clientid": "",
+          "clientsecret": "",
+          "credential-type": "foo"
+          }
+        }
+        """;
+    var binding2 = AiCoreServiceKeyAccessor.createServiceBinding(serviceKeyWithCredentialType);
+    assertThat(binding2.getCredentials().get("credential-type"))
+        .describedAs("The 'credential-type' field should not get overwritten")
+        .isEqualTo("foo");
+  }
 }

docs/release_notes.md

@@ -16,7 +16,8 @@
 
 ### 📈 Improvements
 
--
+- [Core] If the AI Core credentials used are missing an explicit `credential-type` but `clientid` and `clientsecret` are present then `"credential-type": "binding-secret"` is inferred automatically.
+
 
 ### 🐛 Fixed Issues