From 2f7f765076744f0a3cfeaae5fd8554736f3cec40 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Fri, 1 Mar 2019 14:29:09 -0800
Subject: [PATCH 1/2] fix(put): fail if any router fails

---
 parallel.go | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/parallel.go b/parallel.go
index 7851f13..01f8256 100644
--- a/parallel.go
+++ b/parallel.go
@@ -130,12 +130,15 @@ func (r Parallel) put(do func(routing.IpfsRouting) error) error {
 	}
 	wg.Wait()
 
-	var errs []error
+	var (
+		errs    []error
+		success bool
+	)
 	for _, err := range results {
 		switch err {
 		case nil:
-			// Success!
-			return nil
+			// at least one router supports this.
+			success = true
 		case routing.ErrNotSupported:
 		default:
 			errs = append(errs, err)
@@ -144,6 +147,11 @@ func (r Parallel) put(do func(routing.IpfsRouting) error) error {
 
 	switch len(errs) {
 	case 0:
+		if success {
+			// No errors and at least one router succeeded.
+			return nil
+		}
+		// No routers supported this operation.
 		return routing.ErrNotSupported
 	case 1:
 		return errs[0]

From fe54a994b27606d9a49974cbe2fdc91a62ea3092 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Fri, 1 Mar 2019 17:50:38 -0800
Subject: [PATCH 2/2] test(parallel): all parallel puts must succeed

---
 dummy_test.go    | 15 +++++++++++++++
 parallel_test.go | 18 ++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/dummy_test.go b/dummy_test.go
index 1d941d0..494b9ed 100644
--- a/dummy_test.go
+++ b/dummy_test.go
@@ -13,6 +13,21 @@ import (
 	ropts "github.com/libp2p/go-libp2p-routing/options"
 )
 
+type failValueStore struct{}
+
+var failValueErr = errors.New("fail valuestore error")
+
+func (f failValueStore) PutValue(ctx context.Context, key string, value []byte, opts ...ropts.Option) error {
+	return failValueErr
+}
+func (f failValueStore) GetValue(ctx context.Context, key string, opts ...ropts.Option) ([]byte, error) {
+	return nil, failValueErr
+}
+
+func (f failValueStore) SearchValue(ctx context.Context, key string, opts ...ropts.Option) (<-chan []byte, error) {
+	return nil, failValueErr
+}
+
 type dummyValueStore sync.Map
 
 func (d *dummyValueStore) PutValue(ctx context.Context, key string, value []byte, opts ...ropts.Option) error {
diff --git a/parallel_test.go b/parallel_test.go
index b17cdc5..fd3a7e6 100644
--- a/parallel_test.go
+++ b/parallel_test.go
@@ -129,6 +129,24 @@ func TestParallelPutGet(t *testing.T) {
 	cancel()
 }
 
+func TestParallelPutFailure(t *testing.T) {
+	ctx := context.Background()
+	router := Parallel{
+		Routers: []routing.IpfsRouting{
+			&Compose{
+				ValueStore: new(failValueStore),
+			},
+			&Compose{
+				ValueStore: new(dummyValueStore),
+			},
+		},
+	}
+	err := router.PutValue(ctx, "/some/thing", []byte("thing"))
+	if err != failValueErr {
+		t.Fatalf("exected put to fail with %q, got %q", failValueErr, err)
+	}
+}
+
 func TestBasicParallelFindProviders(t *testing.T) {
 	prefix := cid.NewPrefixV1(cid.Raw, mh.SHA2_256)
 	c, _ := prefix.Sum([]byte("foo"))