From 0354e683e554f91d316f90804a3c8d4c3e86f54f Mon Sep 17 00:00:00 2001
From: Tyler Yahn <codingalias@gmail.com>
Date: Wed, 6 Dec 2023 13:21:13 -0800
Subject: [PATCH] Test histogram limit

---
 .../internal/aggregate/histogram_test.go      | 48 +++++++++++++++++--
 1 file changed, 44 insertions(+), 4 deletions(-)

diff --git a/sdk/metric/internal/aggregate/histogram_test.go b/sdk/metric/internal/aggregate/histogram_test.go
index f0075615a04..e51e9fc8f29 100644
--- a/sdk/metric/internal/aggregate/histogram_test.go
+++ b/sdk/metric/internal/aggregate/histogram_test.go
@@ -53,8 +53,9 @@ type conf[N int64 | float64] struct {
 
 func testDeltaHist[N int64 | float64](c conf[N]) func(t *testing.T) {
 	in, out := Builder[N]{
-		Temporality: metricdata.DeltaTemporality,
-		Filter:      attrFltr,
+		Temporality:      metricdata.DeltaTemporality,
+		Filter:           attrFltr,
+		AggregationLimit: 3,
 	}.ExplicitBucketHistogram(bounds, noMinMax, c.noSum)
 	ctx := context.Background()
 	return test[N](in, out, []teststep[N]{
@@ -114,13 +115,34 @@ func testDeltaHist[N int64 | float64](c conf[N]) func(t *testing.T) {
 				},
 			},
 		},
+		{
+			input: []arg[N]{
+				{ctx, 1, alice},
+				{ctx, 1, bob},
+				// These will exceed cardinality limit.
+				{ctx, 1, carol},
+				{ctx, 1, dave},
+			},
+			expect: output{
+				n: 3,
+				agg: metricdata.Histogram[N]{
+					Temporality: metricdata.DeltaTemporality,
+					DataPoints: []metricdata.HistogramDataPoint[N]{
+						c.hPt(fltrAlice, 1, 1),
+						c.hPt(fltrBob, 1, 1),
+						c.hPt(overflowSet, 1, 2),
+					},
+				},
+			},
+		},
 	})
 }
 
 func testCumulativeHist[N int64 | float64](c conf[N]) func(t *testing.T) {
 	in, out := Builder[N]{
-		Temporality: metricdata.CumulativeTemporality,
-		Filter:      attrFltr,
+		Temporality:      metricdata.CumulativeTemporality,
+		Filter:           attrFltr,
+		AggregationLimit: 3,
 	}.ExplicitBucketHistogram(bounds, noMinMax, c.noSum)
 	ctx := context.Background()
 	return test[N](in, out, []teststep[N]{
@@ -182,6 +204,24 @@ func testCumulativeHist[N int64 | float64](c conf[N]) func(t *testing.T) {
 				},
 			},
 		},
+		{
+			input: []arg[N]{
+				// These will exceed cardinality limit.
+				{ctx, 1, carol},
+				{ctx, 1, dave},
+			},
+			expect: output{
+				n: 3,
+				agg: metricdata.Histogram[N]{
+					Temporality: metricdata.CumulativeTemporality,
+					DataPoints: []metricdata.HistogramDataPoint[N]{
+						c.hPt(fltrAlice, 2, 4),
+						c.hPt(fltrBob, 10, 3),
+						c.hPt(overflowSet, 1, 2),
+					},
+				},
+			},
+		},
 	})
 }