Alerting: Copy alert rule metadata when the rule is updated via provisioning API (#93723)

Alerting: Copy alert rule metadata when the rule is updated

pkg/services/ngalert/models/alert_rule.go

@@ -795,6 +795,13 @@ func PatchPartialAlertRule(existingRule *AlertRule, ruleToPatch *AlertRuleWithOp
 	if !ruleToPatch.HasPause {
 		ruleToPatch.IsPaused = existingRule.IsPaused
 	}
+
+	// Currently metadata contains only editor settings, so we can just copy it.
+	// If we add more fields to metadata, we might need to handle them separately,
+	// and/or merge or update their values.
+	if ruleToPatch.Metadata == (AlertRuleMetadata{}) {
+		ruleToPatch.Metadata = existingRule.Metadata
+	}
 }
 
 func ValidateRuleGroupInterval(intervalSeconds, baseIntervalSeconds int64) error {

pkg/services/ngalert/models/alert_rule_test.go

@@ -253,10 +253,17 @@ func TestPatchPartialAlertRule(t *testing.T) {
 					r.IsPaused = true
 				},
 			},
+			{
+				name: "No metadata",
+				mutator: func(r *AlertRuleWithOptionals) {
+					r.Metadata = AlertRuleMetadata{}
+				},
+			},
 		}
 
 		gen := RuleGen.With(
-			RuleMuts.WithFor(time.Duration(rand.Int63n(1000) + 1)),
+			RuleMuts.WithFor(time.Duration(rand.Int63n(1000)+1)),
+			RuleMuts.WithEditorSettingsSimplifiedQueryAndExpressionsSection(true),
 		)
 
 		for _, testCase := range testCases {