refactor: update writeNonTransaction and batchCheck to handle immutable map for headers

Author: ewanharris

src/main/java/dev/openfga/sdk/api/client/OpenFgaClient.java

@@ -558,12 +558,12 @@ private CompletableFuture<ClientWriteResponse> writeNonTransaction(
                 ? writeOptions
                 : new ClientWriteOptions().transactionChunkSize(DEFAULT_MAX_METHOD_PARALLEL_REQS);
 
-        if (options.getAdditionalHeaders() == null) {
-            options.additionalHeaders(new HashMap<>());
-        }
-        options.getAdditionalHeaders().putIfAbsent(CLIENT_METHOD_HEADER, "Write");
-        options.getAdditionalHeaders()
-                .putIfAbsent(CLIENT_BULK_REQUEST_ID_HEADER, randomUUID().toString());
+        HashMap<String, String> headers = options.getAdditionalHeaders() != null
+                ? new HashMap<>(options.getAdditionalHeaders())
+                : new HashMap<>();
+        headers.putIfAbsent(CLIENT_METHOD_HEADER, "Write");
+        headers.putIfAbsent(CLIENT_BULK_REQUEST_ID_HEADER, randomUUID().toString());
+        options.additionalHeaders(headers);
 
         int chunkSize = options.getTransactionChunkSize();
 
@@ -899,12 +899,13 @@ public CompletableFuture<ClientBatchCheckResponse> batchCheck(
                 : new ClientBatchCheckOptions()
                         .maxParallelRequests(DEFAULT_MAX_METHOD_PARALLEL_REQS)
                         .maxBatchSize(DEFAULT_MAX_BATCH_SIZE);
-        if (options.getAdditionalHeaders() == null) {
-            options.additionalHeaders(new HashMap<>());
-        }
-        options.getAdditionalHeaders().putIfAbsent(CLIENT_METHOD_HEADER, "BatchCheck");
-        options.getAdditionalHeaders()
-                .putIfAbsent(CLIENT_BULK_REQUEST_ID_HEADER, randomUUID().toString());
+
+        HashMap<String, String> headers = options.getAdditionalHeaders() != null
+                ? new HashMap<>(options.getAdditionalHeaders())
+                : new HashMap<>();
+        headers.putIfAbsent(CLIENT_METHOD_HEADER, "BatchCheck");
+        headers.putIfAbsent(CLIENT_BULK_REQUEST_ID_HEADER, randomUUID().toString());
+        options.additionalHeaders(headers);
 
         Map<String, ClientBatchCheckItem> correlationIdToCheck = new HashMap<>();
 
@@ -1135,8 +1136,8 @@ public CompletableFuture<ClientListRelationsResponse> listRelations(
         HashMap<String, String> headers = options.getAdditionalHeaders() != null
                 ? new HashMap<>(options.getAdditionalHeaders())
                 : new HashMap<>();
-        headers.put(CLIENT_METHOD_HEADER, "ListRelations");
-        headers.put(CLIENT_BULK_REQUEST_ID_HEADER, randomUUID().toString());
+        headers.putIfAbsent(CLIENT_METHOD_HEADER, "ListRelations");
+        headers.putIfAbsent(CLIENT_BULK_REQUEST_ID_HEADER, randomUUID().toString());
         options.additionalHeaders(headers);
 
         var batchCheckRequests = request.getRelations().stream()

src/test/java/dev/openfga/sdk/api/client/OpenFgaClientHeadersTest.java

@@ -428,6 +428,41 @@ public void write_withHeaders() throws Exception {
         assertEquals(200, response.getStatusCode());
     }
 
+    @Test
+    public void writeNonTransaction_withHeaders() throws Exception {
+        // Given
+        String postPath = String.format("https://api.fga.example/stores/%s/write", DEFAULT_STORE_ID);
+        String expectedBody = String.format(
+                "{\"writes\":{\"tuple_keys\":[{\"user\":\"%s\",\"relation\":\"%s\",\"object\":\"%s\",\"condition\":null}]},\"deletes\":null,\"authorization_model_id\":\"%s\"}",
+                DEFAULT_USER, DEFAULT_RELATION, DEFAULT_OBJECT, DEFAULT_AUTH_MODEL_ID);
+        mockHttpClient
+                .onPost(postPath)
+                .withBody(is(expectedBody))
+                .withHeader("another-header", "another-value")
+                .withHeader("test-header", "test-value-per-call")
+                .doReturn(200, EMPTY_RESPONSE_BODY);
+        ClientWriteRequest request = new ClientWriteRequest()
+                .writes(List.of(new ClientTupleKey()
+                        ._object(DEFAULT_OBJECT)
+                        .relation(DEFAULT_RELATION)
+                        .user(DEFAULT_USER)));
+        ClientWriteOptions options = new ClientWriteOptions()
+                .additionalHeaders(Map.of("test-header", "test-value-per-call"))
+                .disableTransactions(true);
+
+        // When
+        ClientWriteResponse response = fga.write(request, options).get();
+
+        // Then
+        mockHttpClient
+                .verify()
+                .post(postPath)
+                .withHeader("another-header", "another-value")
+                .withHeader("test-header", "test-value-per-call")
+                .called(1);
+        assertEquals(200, response.getStatusCode());
+    }
+
     @Test
     public void check_withHeaders() throws Exception {
         // Given
@@ -480,10 +515,8 @@ public void batchCheck_withHeaders() throws Exception {
                 ._object(DEFAULT_OBJECT)
                 .correlationId("cor-1");
         ClientBatchCheckRequest request = new ClientBatchCheckRequest().checks(List.of(item));
-        // Use HashMap instead of Map.of() to create a mutable map
-        Map<String, String> headers = new java.util.HashMap<>();
-        headers.put("test-header", "test-value-per-call");
-        ClientBatchCheckOptions options = new ClientBatchCheckOptions().additionalHeaders(headers);
+        ClientBatchCheckOptions options =
+                new ClientBatchCheckOptions().additionalHeaders(Map.of("test-header", "test-value-per-call"));
 
         // When
         ClientBatchCheckResponse response = fga.batchCheck(request, options).join();