Merge pull request prometheus#14820 from charleskorn/promqltest-nativ…

…e-histogram-format

promqltest: use test expression format for histograms in assertion failure messages and include reset hint in the test expression

cmd/promtool/testdata/unittest.yml

@@ -69,13 +69,13 @@ tests:
         eval_time: 2m
         exp_samples:
           - labels: "test_histogram_repeat"
-            histogram: "{{count:2 sum:3 buckets:[2]}}"
+            histogram: "{{count:2 sum:3 counter_reset_hint:not_reset buckets:[2]}}"
 
       - expr: test_histogram_increase
         eval_time: 2m
         exp_samples:
           - labels: "test_histogram_increase"
-            histogram: "{{count:4 sum:5.6 buckets:[4]}}"
+            histogram: "{{count:4 sum:5.6 counter_reset_hint:not_reset buckets:[4]}}"
 
       # Ensure a value is stale as soon as it is marked as such.
       - expr: test_stale

model/histogram/float_histogram.go

@@ -230,6 +230,17 @@ func (h *FloatHistogram) TestExpression() string {
 		res = append(res, fmt.Sprintf("custom_values:%g", m.CustomValues))
 	}
 
+	switch m.CounterResetHint {
+	case UnknownCounterReset:
+		// Unknown is the default, don't add anything.
+	case CounterReset:
+		res = append(res, "counter_reset_hint:reset")
+	case NotCounterReset:
+		res = append(res, "counter_reset_hint:not_reset")
+	case GaugeType:
+		res = append(res, "counter_reset_hint:gauge")
+	}
+
 	addBuckets := func(kind, bucketsKey, offsetKey string, buckets []float64, spans []Span) []string {
 		if len(spans) > 1 {
 			panic(fmt.Sprintf("histogram with multiple %s spans not supported", kind))

promql/parser/parse_test.go

@@ -4401,6 +4401,22 @@ func TestHistogramTestExpression(t *testing.T) {
 			},
 			expected: `{{offset:-3 buckets:[5.1 0 0 0 0 10 7] n_offset:-1 n_buckets:[4.1 5 0 0 7 8 9]}}`,
 		},
+		{
+			name: "known counter reset hint",
+			input: histogram.FloatHistogram{
+				Schema:           1,
+				Sum:              -0.3,
+				Count:            3.1,
+				ZeroCount:        7.1,
+				ZeroThreshold:    0.05,
+				PositiveBuckets:  []float64{5.1, 10, 7},
+				PositiveSpans:    []histogram.Span{{Offset: -3, Length: 3}},
+				NegativeBuckets:  []float64{4.1, 5},
+				NegativeSpans:    []histogram.Span{{Offset: -5, Length: 2}},
+				CounterResetHint: histogram.CounterReset,
+			},
+			expected: `{{schema:1 count:3.1 sum:-0.3 z_bucket:7.1 z_bucket_w:0.05 counter_reset_hint:reset offset:-3 buckets:[5.1 10 7] n_offset:-5 n_buckets:[4.1 5]}}`,
+		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			expression := test.input.TestExpression()

promql/promqltest/test.go

@@ -790,7 +790,7 @@ func (ev *evalCmd) compareResult(result parser.Value) error {
 				}
 
 				if !compareNativeHistogram(expected.H.Compact(0), actual.H.Compact(0)) {
-					return fmt.Errorf("expected histogram value at index %v (t=%v) for %s to be %v, but got %v (result has %s)", i, actual.T, ev.metrics[hash], expected.H, actual.H, formatSeriesResult(s))
+					return fmt.Errorf("expected histogram value at index %v (t=%v) for %s to be %v, but got %v (result has %s)", i, actual.T, ev.metrics[hash], expected.H.TestExpression(), actual.H.TestExpression(), formatSeriesResult(s))
 				}
 			}
 		}
@@ -1006,7 +1006,13 @@ func formatSeriesResult(s promql.Series) string {
 		histogramPlural = ""
 	}
 
-	return fmt.Sprintf("%v float point%s %v and %v histogram point%s %v", len(s.Floats), floatPlural, s.Floats, len(s.Histograms), histogramPlural, s.Histograms)
+	histograms := make([]string, 0, len(s.Histograms))
+
+	for _, p := range s.Histograms {
+		histograms = append(histograms, fmt.Sprintf("%v @[%v]", p.H.TestExpression(), p.T))
+	}
+
+	return fmt.Sprintf("%v float point%s %v and %v histogram point%s %v", len(s.Floats), floatPlural, s.Floats, len(s.Histograms), histogramPlural, histograms)
 }
 
 // HistogramTestExpression returns TestExpression() for the given histogram or "" if the histogram is nil.

promql/promqltest/test_test.go

@@ -381,7 +381,7 @@ load 5m
 eval range from 0 to 10m step 5m testmetric
 	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}} {{schema:-1 sum:7 count:1 buckets:[1] offset:1}} {{schema:-1 sum:8 count:1 buckets:[1] offset:1}}
 `,
-			expectedError: `error in eval testmetric (line 5): expected histogram value at index 1 (t=300000) for {__name__="testmetric"} to be {count:1, sum:7, (1,4]:1}, but got {count:1, sum:5, (1,4]:1} (result has 0 float points [] and 3 histogram points [{count:1, sum:4, (1,4]:1} @[0] {count:1, sum:5, (1,4]:1} @[300000] {count:1, sum:6, (1,4]:1} @[600000]])`,
+			expectedError: `error in eval testmetric (line 5): expected histogram value at index 1 (t=300000) for {__name__="testmetric"} to be {{schema:-1 count:1 sum:7 offset:1 buckets:[1]}}, but got {{schema:-1 count:1 sum:5 counter_reset_hint:not_reset offset:1 buckets:[1]}} (result has 0 float points [] and 3 histogram points [{{schema:-1 count:1 sum:4 offset:1 buckets:[1]}} @[0] {{schema:-1 count:1 sum:5 counter_reset_hint:not_reset offset:1 buckets:[1]}} @[300000] {{schema:-1 count:1 sum:6 counter_reset_hint:not_reset offset:1 buckets:[1]}} @[600000]])`,
 		},
 		"range query with too many points for query time range": {
 			input: testData + `
@@ -532,7 +532,7 @@ load 5m
 eval range from 0 to 5m step 5m testmetric
 	testmetric 2 3
 `,
-			expectedError: `error in eval testmetric (line 5): expected 2 float points and 0 histogram points for {__name__="testmetric"}, but got 0 float points [] and 2 histogram points [{count:0, sum:0} @[0] {count:0, sum:0} @[300000]]`,
+			expectedError: `error in eval testmetric (line 5): expected 2 float points and 0 histogram points for {__name__="testmetric"}, but got 0 float points [] and 2 histogram points [{{}} @[0] {{counter_reset_hint:not_reset}} @[300000]]`,
 		},
 		"range query with expected mixed results": {
 			input: `
@@ -552,7 +552,7 @@ load 5m
 eval range from 0 to 5m step 5m testmetric
 	testmetric {{}} 3
 `,
-			expectedError: `error in eval testmetric (line 5): expected float value at index 0 for {__name__="testmetric"} to have timestamp 300000, but it had timestamp 0 (result has 1 float point [3 @[0]] and 1 histogram point [{count:0, sum:0} @[300000]])`,
+			expectedError: `error in eval testmetric (line 5): expected float value at index 0 for {__name__="testmetric"} to have timestamp 300000, but it had timestamp 0 (result has 1 float point [3 @[0]] and 1 histogram point [{{}} @[300000]])`,
 		},
 		"instant query with expected scalar result": {
 			input: `