From 18f93c124334464a951b3d3065bdf11bbda13dac Mon Sep 17 00:00:00 2001
From: Yiru Tang <yiru@google.com>
Date: Thu, 22 Sep 2022 12:58:24 -0700
Subject: [PATCH] feat: add a new specific exception about json data has
 unknown field (#1792)

* feat: add a new specific exception about json data has unknown field

* .

* .

* .
---
 .../cloud/bigquery/storage/v1/Exceptions.java   | 17 +++++++++++++++++
 .../bigquery/storage/v1/JsonToProtoMessage.java |  3 +--
 .../storage/v1/JsonToProtoMessageTest.java      |  3 ++-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/Exceptions.java b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/Exceptions.java
index 2f861d86a5..ae68fcdd8e 100644
--- a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/Exceptions.java
+++ b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/Exceptions.java
@@ -342,6 +342,23 @@ protected InflightBytesLimitExceededException(String writerId, long currentLimit
           currentLimit);
     }
   }
+  /**
+   * Input Json data has unknown field to the schema of the JsonStreamWriter. User can either turn
+   * on IgnoreUnknownFields option on the JsonStreamWriter, or if they don't want the error to be
+   * ignored, they should recreate the JsonStreamWriter with the updated table schema.
+   */
+  public static final class JsonDataHasUnknownFieldException extends IllegalArgumentException {
+    private final String jsonFieldName;
+
+    protected JsonDataHasUnknownFieldException(String jsonFieldName) {
+      super(String.format("JSONObject has fields unknown to BigQuery: %s.", jsonFieldName));
+      this.jsonFieldName = jsonFieldName;
+    }
+
+    public String getFieldName() {
+      return jsonFieldName;
+    }
+  }
 
   private Exceptions() {}
 }
diff --git a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java
index dde3b542bf..3f7a135ce6 100644
--- a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java
+++ b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java
@@ -201,8 +201,7 @@ private static DynamicMessage convertJsonToProtoMessageImpl(
       String currentScope = jsonScope + "." + jsonName;
       FieldDescriptor field = protoSchema.findFieldByName(jsonLowercaseName);
       if (field == null && !ignoreUnknownFields) {
-        throw new IllegalArgumentException(
-            String.format("JSONObject has fields unknown to BigQuery: %s.", currentScope));
+        throw new Exceptions.JsonDataHasUnknownFieldException(currentScope);
       } else if (field == null) {
         continue;
       }
diff --git a/google-cloud-bigquerystorage/src/test/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessageTest.java b/google-cloud-bigquerystorage/src/test/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessageTest.java
index c24a49f858..3abb527ca2 100644
--- a/google-cloud-bigquerystorage/src/test/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessageTest.java
+++ b/google-cloud-bigquerystorage/src/test/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessageTest.java
@@ -1122,8 +1122,9 @@ public void testAllowUnknownFieldsError() throws Exception {
       DynamicMessage protoMsg =
           JsonToProtoMessage.convertJsonToProtoMessage(RepeatedInt64.getDescriptor(), json);
       Assert.fail("Should fail");
-    } catch (IllegalArgumentException e) {
+    } catch (Exceptions.JsonDataHasUnknownFieldException e) {
       assertEquals("JSONObject has fields unknown to BigQuery: root.string.", e.getMessage());
+      assertEquals("root.string", e.getFieldName());
     }
   }