chore: add garbage roundtrip tests for dag-json

To confirm that new refmt JSON decoding changes don't raise any red flags

Ref: polydawn/refmt#58

codec/dagjson/roundtrip_test.go

@@ -2,15 +2,18 @@ package dagjson_test
 
 import (
 	"bytes"
+	"math/rand"
 	"strings"
 	"testing"
+	"time"
 
 	qt "github.com/frankban/quicktest"
 
 	"github.com/ipld/go-ipld-prime/codec/dagjson"
 	"github.com/ipld/go-ipld-prime/fluent"
 	"github.com/ipld/go-ipld-prime/node/basicnode"
 	nodetests "github.com/ipld/go-ipld-prime/node/tests"
+	"github.com/ipld/go-ipld-prime/testutil/garbage"
 )
 
 var n = fluent.MustBuildMap(basicnode.Prototype.Map, 4, func(na fluent.MapAssembler) {
@@ -81,3 +84,53 @@ func TestRoundtripScalar(t *testing.T) {
 		qt.Check(t, nb.Build(), nodetests.NodeContentEquals, simple)
 	})
 }
+
+func TestGarbage(t *testing.T) {
+	t.Run("small garbage", func(t *testing.T) {
+		seed := time.Now().Unix()
+		t.Logf("randomness seed: %v\n", seed)
+		rnd := rand.New(rand.NewSource(seed))
+		for i := 0; i < 1000; i++ {
+			gbg := garbage.Generate(rnd, garbage.TargetBlockSize(1<<6))
+			var buf bytes.Buffer
+			err := dagjson.Encode(gbg, &buf)
+			qt.Assert(t, err, qt.IsNil)
+			nb := basicnode.Prototype.Any.NewBuilder()
+			err = dagjson.Decode(nb, bytes.NewReader(buf.Bytes()))
+			qt.Assert(t, err, qt.IsNil)
+			qt.Check(t, nb.Build(), nodetests.DeepNodeContentsEquals, gbg)
+		}
+	})
+
+	t.Run("medium garbage", func(t *testing.T) {
+		seed := time.Now().Unix()
+		t.Logf("randomness seed: %v\n", seed)
+		rnd := rand.New(rand.NewSource(seed))
+		for i := 0; i < 100; i++ {
+			gbg := garbage.Generate(rnd, garbage.TargetBlockSize(1<<16))
+			var buf bytes.Buffer
+			err := dagjson.Encode(gbg, &buf)
+			qt.Assert(t, err, qt.IsNil)
+			nb := basicnode.Prototype.Any.NewBuilder()
+			err = dagjson.Decode(nb, bytes.NewReader(buf.Bytes()))
+			qt.Assert(t, err, qt.IsNil)
+			qt.Check(t, nb.Build(), nodetests.DeepNodeContentsEquals, gbg)
+		}
+	})
+
+	t.Run("large garbage", func(t *testing.T) {
+		seed := time.Now().Unix()
+		t.Logf("randomness seed: %v\n", seed)
+		rnd := rand.New(rand.NewSource(seed))
+		for i := 0; i < 10; i++ {
+			gbg := garbage.Generate(rnd, garbage.TargetBlockSize(1<<20))
+			var buf bytes.Buffer
+			err := dagjson.Encode(gbg, &buf)
+			qt.Assert(t, err, qt.IsNil)
+			nb := basicnode.Prototype.Any.NewBuilder()
+			err = dagjson.Decode(nb, bytes.NewReader(buf.Bytes()))
+			qt.Assert(t, err, qt.IsNil)
+			qt.Check(t, nb.Build(), nodetests.DeepNodeContentsEquals, gbg)
+		}
+	})
+}

go.mod

@@ -2,6 +2,8 @@ module github.com/ipld/go-ipld-prime
 
 go 1.20
 
+replace github.com/polydawn/refmt => github.com/rvagg/refmt v0.0.0-20230920092505-e600edc52dad
+
 require (
 	github.com/frankban/quicktest v1.14.6
 	github.com/google/go-cmp v0.5.9
@@ -26,6 +28,6 @@ require (
 	github.com/rogpeppe/go-internal v1.9.0 // indirect
 	github.com/spaolacci/murmur3 v1.1.0 // indirect
 	golang.org/x/crypto v0.1.0 // indirect
-	golang.org/x/sys v0.1.0 // indirect
+	golang.org/x/sys v0.6.0 // indirect
 	lukechampine.com/blake3 v1.1.6 // indirect
 )