From f5806bc01c49ab9ed8b239419be48df54a08eaa0 Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Mon, 24 Jan 2022 08:10:01 -0600
Subject: [PATCH] Add a fuzz test
Investigating https://github.com/jackc/pgx/issues/938.
---
chunkreader_test.go | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/chunkreader_test.go b/chunkreader_test.go
index 67a20af2..ddc2fbf6 100644
--- a/chunkreader_test.go
+++ b/chunkreader_test.go
@@ -2,6 +2,7 @@ package chunkreader
import (
"bytes"
+ "math/rand"
"testing"
)
@@ -94,3 +95,34 @@ func TestChunkReaderDoesNotReuseBuf(t *testing.T) {
t.Fatalf("Expected KeepLast to prevent Next from overwriting buf, expected %v but it was %v", src[0:4], n1)
}
}
+
+type randomReader struct {
+ rnd *rand.Rand
+}
+
+// Read reads a random number of random bytes.
+func (r *randomReader) Read(p []byte) (n int, err error) {
+ n = r.rnd.Intn(len(p) + 1)
+ return r.rnd.Read(p[:n])
+}
+
+func TestChunkReaderNextFuzz(t *testing.T) {
+ rr := &randomReader{rnd: rand.New(rand.NewSource(1))}
+ r, err := NewConfig(rr, Config{MinBufLen: 8192})
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ randomSizes := rand.New(rand.NewSource(0))
+
+ for i := 0; i < 100000; i++ {
+ size := randomSizes.Intn(16384) + 1
+ buf, err := r.Next(size)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if len(buf) != size {
+ t.Fatalf("Expected to get %v bytes but got %v bytes", size, len(buf))
+ }
+ }
+}