don't return dev messages in getUserMessage()

src/main/java/com/stripe/exception/StripeException.java

@@ -64,8 +64,8 @@ protected StripeException(
   }
 
   /**
-   * Returns a description of the exception, including the HTTP status code and request ID (if
-   * applicable).
+   * Returns a developer-facing description of the exception, including the HTTP status code and
+   * request ID (if applicable).
    *
    * @return a string representation of the exception.
    */
@@ -79,25 +79,22 @@ public String getMessage() {
       additionalInfo += "; request-id: " + requestId;
     }
     // a separate user message is only available on v2 errors
-    if (stripeErrorApiMode == ApiMode.V2 && this.getUserMessage() != null) {
-      additionalInfo += "; user-message: " + this.getUserMessage();
+    String userMessage = this.getUserMessage();
+    if (userMessage != null) {
+      additionalInfo += "; user-message: " + userMessage;
     }
     return super.getMessage() + additionalInfo;
   }
 
   /**
-   * Returns a description of the user facing exception
+   * Returns a description of the issue suitable to show an end-user (if available).
    *
-   * @return a string representation of the user facing exception.
+   * @return a string representation of the user facing exception (or null).
    */
   public String getUserMessage() {
-    if (this.getStripeError() != null) {
-      switch (stripeErrorApiMode) {
-        case V1:
-          return this.getStripeError().getMessage();
-        case V2:
-          return this.getStripeError().getUserMessage();
-      }
+    // only V2 errors have (optional) user messages
+    if (this.getStripeError() != null && stripeErrorApiMode == ApiMode.V2) {
+      return this.getStripeError().getUserMessage();
     }
     return null;
   }

src/test/java/com/stripe/exception/StripeExceptionTest.java

@@ -33,7 +33,8 @@ public void testSetStripeError() throws IOException {
     assertEquals(
         "Received unknown parameter: foo; code: parameter_unknown; request-id: 1234",
         exception.getMessage());
-    assertEquals(error.getMessage(), exception.getUserMessage());
+    // v1 errors don't have user messages
+    assertEquals(null, exception.getUserMessage());
   }
 
   @Test