Merge pull request #76 from ipfs/fix/unlink

fix: return the correct error from RemoveChild

Author: Stebalien

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/ipfs/go-ipfs-posinfo v0.0.1
 	github.com/ipfs/go-ipfs-util v0.0.1
 	github.com/ipfs/go-ipld-format v0.0.2
-	github.com/ipfs/go-merkledag v0.2.2
+	github.com/ipfs/go-merkledag v0.2.3
 	github.com/multiformats/go-multihash v0.0.5
 	github.com/polydawn/refmt v0.0.0-20190408063855-01bf1e26dd14 // indirect
 	github.com/smartystreets/assertions v1.0.0 // indirect

go.sum

@@ -114,8 +114,8 @@ github.com/ipfs/go-ipld-format v0.0.2 h1:OVAGlyYT6JPZ0pEfGntFPS40lfrDmaDbQwNHEY2
 github.com/ipfs/go-ipld-format v0.0.2/go.mod h1:4B6+FM2u9OJ9zCV+kSbgFAZlOrv1Hqbf0INGQgiKf9k=
 github.com/ipfs/go-log v0.0.1 h1:9XTUN/rW64BCG1YhPK9Hoy3q8nr4gOmHHBpgFdfw6Lc=
 github.com/ipfs/go-log v0.0.1/go.mod h1:kL1d2/hzSpI0thNYjiKfjanbVNU+IIGA/WnNESY9leM=
-github.com/ipfs/go-merkledag v0.2.2 h1:cw3eEYSH8L1gGa+HTDB08Q7hh5EUfztKf075JIlg5ww=
-github.com/ipfs/go-merkledag v0.2.2/go.mod h1:SQiXrtSts3KGNmgOzMICy5c0POOpUNQLvB3ClKnBAlk=
+github.com/ipfs/go-merkledag v0.2.3 h1:aMdkK9G1hEeNvn3VXfiEMLY0iJnbiQQUHnM0HFJREsE=
+github.com/ipfs/go-merkledag v0.2.3/go.mod h1:SQiXrtSts3KGNmgOzMICy5c0POOpUNQLvB3ClKnBAlk=
 github.com/ipfs/go-metrics-interface v0.0.1 h1:j+cpbjYvu4R8zbleSs36gvB7jR+wsL2fGD6n0jO4kdg=
 github.com/ipfs/go-metrics-interface v0.0.1/go.mod h1:6s6euYU4zowdslK0GKHmqaIZ3j/b/tL7HTWtJ4VPgWY=
 github.com/ipfs/go-peertaskqueue v0.1.0 h1:bpRbgv76eT4avutNPDFZuCPOQus6qTgurEYxfulgZW4=

hamt/hamt.go

@@ -221,7 +221,8 @@ func (ds *Shard) Set(ctx context.Context, name string, nd ipld.Node) error {
 	return ds.modifyValue(ctx, hv, name, lnk)
 }
 
-// Remove deletes the named entry if it exists, this operation is idempotent.
+// Remove deletes the named entry if it exists. Otherwise, it returns
+// os.ErrNotExist.
 func (ds *Shard) Remove(ctx context.Context, name string) error {
 	hv := &hashBits{b: hash([]byte(name))}
 	return ds.modifyValue(ctx, hv, name, nil)

io/directory.go

@@ -48,9 +48,13 @@ type Directory interface {
 
 	// Find returns the root node of the file named 'name' within this directory.
 	// In the case of HAMT-directories, it will traverse the tree.
+	//
+	// Returns os.ErrNotExist if the child does not exist.
 	Find(context.Context, string) (ipld.Node, error)
 
 	// RemoveChild removes the child with the given name.
+	//
+	// Returns os.ErrNotExist if the child doesn't exist.
 	RemoveChild(context.Context, string) error
 
 	// GetNode returns the root of this directory.
@@ -196,7 +200,11 @@ func (d *BasicDirectory) Find(ctx context.Context, name string) (ipld.Node, erro
 
 // RemoveChild implements the `Directory` interface.
 func (d *BasicDirectory) RemoveChild(ctx context.Context, name string) error {
-	return d.node.RemoveNodeLink(name)
+	err := d.node.RemoveNodeLink(name)
+	if err == mdag.ErrLinkNotFound {
+		err = os.ErrNotExist
+	}
+	return err
 }
 
 // GetNode implements the `Directory` interface.