SERVER-49499 Upgrade/downgrade behavior and testing for generating document validation errors

4 files changed, 30 insertions, 7 deletions

diff --git a/src/mongo/base/error_codes.yml b/src/mongo/base/error_codes.yml
index fe34bf4f7d8..676d675dc00 100644
--- a/src/mongo/base/error_codes.yml
+++ b/src/mongo/base/error_codes.yml
@@ -153,7 +153,9 @@ error_codes:
     - {code: 120,name: OplogStartMissing}
     # Error code 121 is only for the document validator on collections.
     - {code: 121,name: DocumentValidationFailure,
-                extra: 'doc_validation_error::DocumentValidationFailureInfo'}
+                extra: 'doc_validation_error::DocumentValidationFailureInfo',
+                # TODO SERVER-50524: Make extra info mandatory when 5.0 becomes last-lts.
+                extraIsOptional: True}
     - {code: 122,name: OBSOLETE_ReadAfterOptimeTimeout}
     - {code: 123,name: NotAReplicaSet}
     - {code: 124,name: IncompatibleElectionProtocol}
diff --git a/src/mongo/db/catalog/collection_impl.cpp b/src/mongo/db/catalog/collection_impl.cpp
index 30520fe8a54..c113ce8e34c 100644
--- a/src/mongo/db/catalog/collection_impl.cpp
+++ b/src/mongo/db/catalog/collection_impl.cpp
@@ -65,6 +65,7 @@
 #include "mongo/db/query/internal_plans.h"
 #include "mongo/db/repl/oplog.h"
 #include "mongo/db/repl/replication_coordinator.h"
+#include "mongo/db/server_options.h"
 #include "mongo/db/service_context.h"
 #include "mongo/db/storage/durable_catalog.h"
 #include "mongo/db/storage/key_string.h"
@@ -400,7 +401,15 @@ Status CollectionImpl::checkValidation(OperationContext* opCtx, const BSONObj& d
     if (validatorMatchExpr->matchesBSON(document))
         return Status::OK();
 
-    BSONObj generatedError = doc_validation_error::generateError(*validatorMatchExpr, document);
+    // TODO SERVER-50524: remove these FCV checks when 5.0 becomes last-lts in order to make sure
+    // that an upgrade from 4.4 directly to the 5.0 LTS version is supported.
+    const auto isFCVAtLeast47 = serverGlobalParams.featureCompatibility.isVersionInitialized() &&
+        serverGlobalParams.featureCompatibility.isGreaterThanOrEqualTo(
+            ServerGlobalParams::FeatureCompatibility::Version::kVersion47);
+    BSONObj generatedError;
+    if (isFCVAtLeast47) {
+        generatedError = doc_validation_error::generateError(*validatorMatchExpr, document);
+    }
 
     if (_validationAction == ValidationAction::WARN) {
         LOGV2_WARNING(20294,
@@ -411,8 +420,13 @@ Status CollectionImpl::checkValidation(OperationContext* opCtx, const BSONObj& d
         return Status::OK();
     }
 
-    return {doc_validation_error::DocumentValidationFailureInfo(generatedError),
-            "Document failed validation"};
+    static constexpr auto kValidationFailureErrorStr = "Document failed validation"_sd;
+    if (isFCVAtLeast47) {
+        return {doc_validation_error::DocumentValidationFailureInfo(generatedError),
+                kValidationFailureErrorStr};
+    } else {
+        return {ErrorCodes::DocumentValidationFailure, kValidationFailureErrorStr};
+    }
 }
 
 Collection::Validator CollectionImpl::parseValidator(
diff --git a/src/mongo/db/commands/write_commands/write_commands.cpp b/src/mongo/db/commands/write_commands/write_commands.cpp
index 8c0d4e0549d..e79e9ce5581 100644
--- a/src/mongo/db/commands/write_commands/write_commands.cpp
+++ b/src/mongo/db/commands/write_commands/write_commands.cpp
@@ -154,8 +154,9 @@ void serializeReply(OperationContext* opCtx,
                 BSONObjBuilder errInfo(error.subobjStart("errInfo"));
                 staleInfo->serialize(&errInfo);
             }
-        } else if (auto docValidationError =
-                       status.extraInfo<doc_validation_error::DocumentValidationFailureInfo>()) {
+        } else if (ErrorCodes::DocumentValidationFailure == status.code() && status.extraInfo()) {
+            auto docValidationError =
+                status.extraInfo<doc_validation_error::DocumentValidationFailureInfo>();
             error.append("code", static_cast<int>(ErrorCodes::DocumentValidationFailure));
             error.append("errInfo", docValidationError->getDetails());
         } else {
diff --git a/src/mongo/db/matcher/doc_validation_error.cpp b/src/mongo/db/matcher/doc_validation_error.cpp
index c5320f88bc5..bbc2f4eb1cb 100644
--- a/src/mongo/db/matcher/doc_validation_error.cpp
+++ b/src/mongo/db/matcher/doc_validation_error.cpp
@@ -974,6 +974,10 @@ bool hasErrorAnnotations(const MatchExpression& validatorExpr) {
 }  // namespace
 
 std::shared_ptr<const ErrorExtraInfo> DocumentValidationFailureInfo::parse(const BSONObj& obj) {
+    if (!obj.hasField("errInfo"_sd)) {
+        // TODO SERVER-50524: remove this block when 5.0 becomes last-lts.
+        return nullptr;
+    }
     auto errInfo = obj["errInfo"];
     uassert(4878100,
             "DocumentValidationFailureInfo must have a field 'errInfo' of type object",
@@ -993,7 +997,9 @@ BSONObj generateError(const MatchExpression& validatorExpr, const BSONObj& doc)
     ValidationErrorInVisitor inVisitor{&context};
     ValidationErrorPostVisitor postVisitor{&context};
     // TODO SERVER-49446: Once all nodes have ErrorAnnotations, this check should be converted to an
-    // invariant check that all nodes have an annotation.
+    // invariant check that all nodes have an annotation. Also add an invariant to the
+    // DocumentValidationFailureInfo constructor to check that it is initialized with a non-empty
+    // object.
     if (!hasErrorAnnotations(validatorExpr)) {
         return BSONObj();
     }