fix!: return Java API error codes as strings

Author: javorosas

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.0.0] - 2026-07-17
+
+### Changed
+
+- Change `FacturapiException.getErrorCode()` to return strings, including converted legacy numeric codes.
+
 ## [1.3.0] - 2026-06-07
 
 ### Added

pom.xml

@@ -5,7 +5,7 @@
 
   <groupId>io.facturapi</groupId>
   <artifactId>facturapi-java</artifactId>
-  <version>1.3.0</version>
+  <version>2.0.0</version>
   <name>facturapi-java</name>
   <description>Official Java SDK for Facturapi</description>
   <url>https://github.com/facturapi/facturapi-java</url>

src/main/java/io/facturapi/FacturapiException.java

@@ -7,7 +7,7 @@
 
 public class FacturapiException extends RuntimeException {
   private final int statusCode;
-  private final Object errorCode;
+  private final String errorCode;
   private final String errorPath;
   private final String errorLocation;
   private final JsonNode errors;
@@ -29,14 +29,14 @@ public FacturapiException(String message, Throwable cause) {
     this.headers = Collections.emptyMap();
   }
 
-  public FacturapiException(String message, int statusCode, Object errorCode, String errorPath) {
+  public FacturapiException(String message, int statusCode, String errorCode, String errorPath) {
     this(message, statusCode, errorCode, errorPath, null, null, null, Collections.emptyMap());
   }
 
   public FacturapiException(
     String message,
     int statusCode,
-    Object errorCode,
+    String errorCode,
     String errorPath,
     String errorLocation,
     JsonNode errors,
@@ -57,7 +57,7 @@ public int getStatusCode() {
     return statusCode;
   }
 
-  public Object getErrorCode() {
+  public String getErrorCode() {
     return errorCode;
   }
 

src/main/java/io/facturapi/http/FacturapiHttpClient.java

@@ -210,7 +210,7 @@ private static JsonNode firstDefined(JsonNode node, String... keys) {
   private FacturapiException buildApiException(String bodyText, Response response) {
     int statusCode = response.code();
     int resolvedStatus = statusCode;
-    Object errorCode = null;
+    String errorCode = null;
     String errorPath = null;
     String errorLocation = null;
     JsonNode errors = null;
@@ -246,17 +246,7 @@ private FacturapiException buildApiException(String bodyText, Response response)
 
           JsonNode codeNode = firstDefined(root, "code");
           if (codeNode != null && !codeNode.isNull()) {
-            if (codeNode.isTextual()) {
-              errorCode = codeNode.asText();
-            } else if (codeNode.isIntegralNumber()) {
-              errorCode = codeNode.intValue();
-            } else if (codeNode.isNumber()) {
-              errorCode = codeNode.numberValue();
-            } else if (codeNode.isBoolean()) {
-              errorCode = codeNode.asBoolean();
-            } else {
-              errorCode = codeNode.toString();
-            }
+            errorCode = codeNode.isValueNode() ? codeNode.asText() : codeNode.toString();
           }
 
           JsonNode pathNode = firstDefined(root, "path");

src/test/java/io/facturapi/FacturapiHttpClientTest.java

@@ -77,4 +77,23 @@ void throwsFacturapiExceptionWithApiMessage() {
     assertEquals("3", ex.getHeaders().get("Retry-After").get(0));
     assertEquals("log_123", ex.getHeaders().get("x-facturapi-log-id").get(0));
   }
+
+  @Test
+  void convertsNumericApiErrorCodesToStrings() {
+    StubHttpClient httpClient = new StubHttpClient();
+    httpClient.enqueueJson(400, "{\"message\":\"Invalid customer\",\"code\":400}");
+
+    FacturapiHttpClient client = new FacturapiHttpClient(
+      FacturapiConfig.builder("sk_test_123")
+        .httpClient(httpClient.client())
+        .build()
+    );
+
+    FacturapiException ex = assertThrows(
+      FacturapiException.class,
+      () -> client.get("/customers/cus_1", null, GenericResponse.class)
+    );
+
+    assertEquals("400", ex.getErrorCode());
+  }
 }