[FIX] PromQL: Updates annotation for bin op between incompatible histograms (prometheus#15895)

PromQL: Updates annotation for bin op between incompatible histograms

---------

Signed-off-by: Neeraj Gartia <neerajgartia211002@gmail.com>

Author: NeerajGartia21

promql/engine.go

@@ -3475,15 +3475,14 @@ func handleVectorBinopError(err error, e *parser.BinaryExpr) annotations.Annotat
 	if err == nil {
 		return nil
 	}
-	metricName := ""
+	op := parser.ItemTypeStr[e.Op]
 	pos := e.PositionRange()
 	if errors.Is(err, annotations.PromQLInfo) || errors.Is(err, annotations.PromQLWarning) {
 		return annotations.New().Add(err)
 	}
-	if errors.Is(err, histogram.ErrHistogramsIncompatibleSchema) {
-		return annotations.New().Add(annotations.NewMixedExponentialCustomHistogramsWarning(metricName, pos))
-	} else if errors.Is(err, histogram.ErrHistogramsIncompatibleBounds) {
-		return annotations.New().Add(annotations.NewIncompatibleCustomBucketsHistogramsWarning(metricName, pos))
+	// TODO(NeerajGartia21): Test the exact annotation output once the testing framework can do so.
+	if errors.Is(err, histogram.ErrHistogramsIncompatibleSchema) || errors.Is(err, histogram.ErrHistogramsIncompatibleBounds) {
+		return annotations.New().Add(annotations.NewIncompatibleBucketLayoutInBinOpWarning(op, pos))
 	}
 	return nil
 }

util/annotations/annotations.go

@@ -143,6 +143,7 @@ var (
 	NativeHistogramNotGaugeWarning             = fmt.Errorf("%w: this native histogram metric is not a gauge:", PromQLWarning)
 	MixedExponentialCustomHistogramsWarning    = fmt.Errorf("%w: vector contains a mix of histograms with exponential and custom buckets schemas for metric name", PromQLWarning)
 	IncompatibleCustomBucketsHistogramsWarning = fmt.Errorf("%w: vector contains histograms with incompatible custom buckets for metric name", PromQLWarning)
+	IncompatibleBucketLayoutInBinOpWarning     = fmt.Errorf("%w: incompatible bucket layout encountered for binary operator", PromQLWarning)
 
 	PossibleNonCounterInfo                  = fmt.Errorf("%w: metric might not be a counter, name does not end in _total/_sum/_count/_bucket:", PromQLInfo)
 	HistogramQuantileForcedMonotonicityInfo = fmt.Errorf("%w: input to histogram_quantile needed to be fixed for monotonicity (see https://prometheus.io/docs/prometheus/latest/querying/functions/#histogram_quantile) for metric name", PromQLInfo)
@@ -295,9 +296,20 @@ func NewHistogramIgnoredInAggregationInfo(aggregation string, pos posrange.Posit
 	}
 }
 
+// NewHistogramIgnoredInMixedRangeInfo is used when a histogram is ignored
+// in a range vector which contains mix of floats and histograms.
 func NewHistogramIgnoredInMixedRangeInfo(metricName string, pos posrange.PositionRange) error {
 	return annoErr{
 		PositionRange: pos,
 		Err:           fmt.Errorf("%w %q", HistogramIgnoredInMixedRangeInfo, metricName),
 	}
 }
+
+// NewIncompatibleBucketLayoutInBinOpWarning is used if binary operators act on a
+// combination of two incompatible histograms.
+func NewIncompatibleBucketLayoutInBinOpWarning(operator string, pos posrange.PositionRange) error {
+	return annoErr{
+		PositionRange: pos,
+		Err:           fmt.Errorf("%w %s", IncompatibleBucketLayoutInBinOpWarning, operator),
+	}
+}