From cd83556e8fbb9f567e9a357a3231e9e5aa53cbf8 Mon Sep 17 00:00:00 2001
From: Armand Grillet <2117580+armandgrillet@users.noreply.github.com>
Date: Mon, 17 Jan 2022 12:06:16 +0100
Subject: [PATCH] [v7.5.x] Alerting: Fix NoDataFound for alert rules using AND
 operator (#41305) (#44066)

* Alerting: Fix NoDataFound for alert rules using AND operator (#41305)

This commit fixes an issue in alerting where NoDataFound is false
when using the AND operator to compare two conditions in an alert
rule and one of the conditions has no data.

* fix typo

* Update yarn.lock

Co-authored-by: Yuriy Tseretyan <yuriy.tseretyan@grafana.com>
---
 pkg/services/alerting/eval_handler.go      |  7 +++++--
 pkg/services/alerting/eval_handler_test.go |  4 ++--
 yarn.lock                                  | 18 +++++++++---------
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/pkg/services/alerting/eval_handler.go b/pkg/services/alerting/eval_handler.go
index 323570a2f26..0b12adbd801 100644
--- a/pkg/services/alerting/eval_handler.go
+++ b/pkg/services/alerting/eval_handler.go
@@ -49,12 +49,15 @@ func (e *DefaultEvalHandler) Eval(context *EvalContext) {
 		// calculating Firing based on operator
 		if cr.Operator == "or" {
 			firing = firing || cr.Firing
-			noDataFound = noDataFound || cr.NoDataFound
 		} else {
 			firing = firing && cr.Firing
-			noDataFound = noDataFound && cr.NoDataFound
 		}
 
+		// We cannot evaluate the expression when one or more conditions are missing data
+		// and so noDataFound should be true if at least one condition returns no data,
+		// irrespective of the operator.
+		noDataFound = noDataFound || cr.NoDataFound
+
 		if i > 0 {
 			conditionEvals = "[" + conditionEvals + " " + strings.ToUpper(cr.Operator) + " " + strconv.FormatBool(cr.Firing) + "]"
 		} else {
diff --git a/pkg/services/alerting/eval_handler_test.go b/pkg/services/alerting/eval_handler_test.go
index 218dffca158..ea1fc54b24a 100644
--- a/pkg/services/alerting/eval_handler_test.go
+++ b/pkg/services/alerting/eval_handler_test.go
@@ -181,7 +181,7 @@ func TestAlertingEvaluationHandler(t *testing.T) {
 			So(context.NoDataFound, ShouldBeTrue)
 		})
 
-		Convey("Should not return no data if at least one condition has no data and using AND", func() {
+		Convey("Should return no data if at least one condition has no data and using AND", func() {
 			context := NewEvalContext(context.TODO(), &Rule{
 				Conditions: []Condition{
 					&conditionStub{operator: "and", noData: true},
@@ -190,7 +190,7 @@ func TestAlertingEvaluationHandler(t *testing.T) {
 			}, &validations.OSSPluginRequestValidator{})
 
 			handler.Eval(context)
-			So(context.NoDataFound, ShouldBeFalse)
+			So(context.NoDataFound, ShouldBeTrue)
 		})
 
 		Convey("Should return no data if at least one condition has no data and using OR", func() {
diff --git a/yarn.lock b/yarn.lock
index fc467f34394..c17e6153bed 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9567,19 +9567,19 @@ caniuse-db@1.0.30000772:
   integrity sha1-UarokXaChureSj2DGep21qAbUSs=
 
 caniuse-lite@^1.0.0, caniuse-lite@^1.0.30001173:
-  version "1.0.30001178"
-  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001178.tgz#3ad813b2b2c7d585b0be0a2440e1e233c6eabdbc"
-  integrity sha512-VtdZLC0vsXykKni8Uztx45xynytOi71Ufx9T8kHptSw9AL4dpqailUJJHavttuzUe1KYuBYtChiWv+BAb7mPmQ==
+  version "1.0.30001299"
+  resolved "https://registry.npmjs.org/caniuse-lite/-/caniuse-lite-1.0.30001299.tgz"
+  integrity sha512-iujN4+x7QzqA2NCSrS5VUy+4gLmRd4xv6vbBBsmfVqTx8bLAD8097euLqQgKxSVLvxjSDcvF1T/i9ocgnUFexw==
 
 caniuse-lite@^1.0.30000981, caniuse-lite@^1.0.30001020, caniuse-lite@^1.0.30001035, caniuse-lite@^1.0.30001093:
-  version "1.0.30001104"
-  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001104.tgz#4e3d5b3b1dd3c3529f10cb7f519c62ba3e579f5d"
-  integrity sha512-pkpCg7dmI/a7WcqM2yfdOiT4Xx5tzyoHAXWsX5/HxZ3TemwDZs0QXdqbE0UPLPVy/7BeK7693YfzfRYfu1YVpg==
+  version "1.0.30001299"
+  resolved "https://registry.npmjs.org/caniuse-lite/-/caniuse-lite-1.0.30001299.tgz"
+  integrity sha512-iujN4+x7QzqA2NCSrS5VUy+4gLmRd4xv6vbBBsmfVqTx8bLAD8097euLqQgKxSVLvxjSDcvF1T/i9ocgnUFexw==
 
 caniuse-lite@^1.0.30001109:
-  version "1.0.30001179"
-  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001179.tgz#b0803883b4471a6c62066fb1752756f8afc699c8"
-  integrity sha512-blMmO0QQujuUWZKyVrD1msR4WNDAqb/UPO1Sw2WWsQ7deoM5bJiicKnWJ1Y0NS/aGINSnKPIWBMw5luX+NDUCA==
+  version "1.0.30001299"
+  resolved "https://registry.npmjs.org/caniuse-lite/-/caniuse-lite-1.0.30001299.tgz"
+  integrity sha512-iujN4+x7QzqA2NCSrS5VUy+4gLmRd4xv6vbBBsmfVqTx8bLAD8097euLqQgKxSVLvxjSDcvF1T/i9ocgnUFexw==
 
 capture-exit@^2.0.0:
   version "2.0.0"