SERVER-66808 Remove undocumented fields from the change stream error

3 files changed, 21 insertions, 8 deletions

diff --git a/src/mongo/db/pipeline/document_source_change_stream_add_post_image.cpp b/src/mongo/db/pipeline/document_source_change_stream_add_post_image.cpp
index ab3f95abca1..822e41f3352 100644
--- a/src/mongo/db/pipeline/document_source_change_stream_add_post_image.cpp
+++ b/src/mongo/db/pipeline/document_source_change_stream_add_post_image.cpp
@@ -48,6 +48,8 @@ REGISTER_INTERNAL_DOCUMENT_SOURCE(_internalChangeStreamAddPostImage,
                                   DocumentSourceChangeStreamAddPostImage::createFromBson,
                                   true);
 
+constexpr auto makePostImageNotFoundErrorMsg =
+    &DocumentSourceChangeStreamAddPreImage::makePreImageNotFoundErrorMsg;
 
 Value assertFieldHasType(const Document& fullDoc, StringData fieldName, BSONType expectedType) {
     auto val = fullDoc[fieldName];
@@ -97,12 +99,11 @@ DocumentSource::GetNextResult DocumentSourceChangeStreamAddPostImage::doGetNext(
     const auto postImageDoc = (_fullDocumentMode == FullDocumentModeEnum::kUpdateLookup
                                    ? lookupLatestPostImage(output.peek())
                                    : generatePostImage(output.peek()));
-    uassert(
-        ErrorCodes::NoMatchingDocument,
-        str::stream() << "Change stream was configured to require a post-image for all update, "
-                         "delete and replace events, but the post-image was not found for event: "
-                      << output.peek().toString(),
-        postImageDoc || _fullDocumentMode != FullDocumentModeEnum::kRequired);
+    uassert(ErrorCodes::NoMatchingDocument,
+            str::stream() << "Change stream was configured to require a post-image for all update "
+                             "events, but the post-image was not found for event: "
+                          << makePostImageNotFoundErrorMsg(output.peek()),
+            postImageDoc || _fullDocumentMode != FullDocumentModeEnum::kRequired);
 
     // Even if no post-image was found, we have to populate the 'fullDocument' field.
     output[kFullDocumentFieldName] = (postImageDoc ? Value(*postImageDoc) : Value(BSONNULL));
diff --git a/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.cpp b/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.cpp
index 6b37f50f723..aca01dda4d3 100644
--- a/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.cpp
+++ b/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.cpp
@@ -99,7 +99,7 @@ DocumentSource::GetNextResult DocumentSourceChangeStreamAddPreImage::doGetNext()
                 str::stream()
                     << "Change stream was configured to require a pre-image for all update, delete "
                        "and replace events, but pre-image id was not available for event: "
-                    << input.getDocument().toString(),
+                    << makePreImageNotFoundErrorMsg(input.getDocument()),
                 _fullDocumentBeforeChangeMode != FullDocumentBeforeChangeModeEnum::kRequired);
         return input;
     }
@@ -113,7 +113,7 @@ DocumentSource::GetNextResult DocumentSourceChangeStreamAddPreImage::doGetNext()
         ErrorCodes::NoMatchingDocument,
         str::stream() << "Change stream was configured to require a pre-image for all update, "
                          "delete and replace events, but the pre-image was not found for event: "
-                      << input.getDocument().toString(),
+                      << makePreImageNotFoundErrorMsg(input.getDocument()),
         preImageDoc ||
             _fullDocumentBeforeChangeMode != FullDocumentBeforeChangeModeEnum::kRequired);
 
@@ -167,4 +167,13 @@ Value DocumentSourceChangeStreamAddPreImage::serialize(
                DocumentSourceChangeStreamAddPreImageSpec(_fullDocumentBeforeChangeMode).toBSON()}});
 }
 
+std::string DocumentSourceChangeStreamAddPreImage::makePreImageNotFoundErrorMsg(
+    const Document& event) {
+    auto errMsgDoc = Document{{"operationType", event["operationType"]},
+                              {"ns", event["ns"]},
+                              {"clusterTime", event["clusterTime"]},
+                              {"txnNumber", event["txnNumber"]}};
+    return errMsgDoc.toString();
+}
+
 }  // namespace mongo
diff --git a/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.h b/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.h
index cc735fc135e..e04ac9a30ef 100644
--- a/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.h
+++ b/src/mongo/db/pipeline/document_source_change_stream_add_pre_image.h
@@ -63,6 +63,9 @@ public:
     static boost::optional<Document> lookupPreImage(boost::intrusive_ptr<ExpressionContext> pExpCtx,
                                                     const Document& preImageId);
 
+    // Removes the internal fields from the event and returns the string representation of it.
+    static std::string makePreImageNotFoundErrorMsg(const Document& event);
+
     DocumentSourceChangeStreamAddPreImage(const boost::intrusive_ptr<ExpressionContext>& expCtx,
                                           FullDocumentBeforeChangeModeEnum mode)
         : DocumentSource(kStageName, expCtx), _fullDocumentBeforeChangeMode(mode) {