From 09e527a6c7ba76e3d07be36c5b4e90bbe5ad9d3c Mon Sep 17 00:00:00 2001
From: Jeroen Demeyer <jeroen.demeyer@be-mobile.com>
Date: Mon, 22 Apr 2024 11:29:12 +0200
Subject: [PATCH] [Go] add BenchmarkBuildAllocations

---
 tests/go_test.go | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tests/go_test.go b/tests/go_test.go
index f230060a66f..e072705a222 100644
--- a/tests/go_test.go
+++ b/tests/go_test.go
@@ -2573,3 +2573,21 @@ func BenchmarkBuildGold(b *testing.B) {
 		bldr.Finish(mon)
 	}
 }
+
+// Benchmark adding 130 bytes, one by one.
+// Unlike BenchmarkBuildGold, we create a new builder every time,
+// to test the performance of growing the buffer.
+func BenchmarkBuildAllocations(b *testing.B) {
+	b.SetBytes(130)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bldr := flatbuffers.NewBuilder(0)
+		for j := 0; j < 130; j++ {
+			bldr.PrependByte(byte(j))
+		}
+		if len(bldr.Bytes) != 256 {
+			b.Fatalf("expected buffer size=256, got %d", len(bldr.Bytes))
+		}
+	}
+}