json as separate codec

adl/rot13adl/example_test.go

@@ -20,7 +20,7 @@ func ExampleUnmarshallingToADL() {
 	nb := rot13adl.Prototype.SubstrateRoot.NewBuilder()
 
 	// Unmarshal -- using the substrate's nodebuilder just like you'd unmarshal with any other nodebuilder.
-	err := dagjson.Unmarshal(nb, json.NewDecoder(strings.NewReader(`"n pbby fgevat"`)))
+	err := dagjson.Unmarshal(nb, json.NewDecoder(strings.NewReader(`"n pbby fgevat"`)), true)
 	fmt.Printf("unmarshal error: %v\n", err)
 
 	// Use `Reify` to get the synthetic high-level view of the ADL data.

codec/dagjson/multicodec.go

@@ -17,23 +17,11 @@ var (
 
 func init() {
 	multicodec.RegisterEncoder(0x0129, Encode)
-	multicodec.RegisterEncoder(0x0200, Encode)
 	multicodec.RegisterDecoder(0x0129, Decode)
-	multicodec.RegisterDecoder(0x0200, decodeNonDagJSON)
 }
 
 func Decode(na ipld.NodeAssembler, r io.Reader) error {
-	return decode(na, r, true)
-}
-
-func decodeNonDagJSON(na ipld.NodeAssembler, r io.Reader) error {
-	return decode(na, r, false)
-}
-
-func decode(na ipld.NodeAssembler, r io.Reader, parseLinks bool) error {
-	// Shell out directly to generic builder path.
-	//  (There's not really any fastpaths of note for json.)
-	err := unmarshal(na, json.NewDecoder(r), parseLinks)
+	err := Unmarshal(na, json.NewDecoder(r), true)
 	if err != nil {
 		return err
 	}

codec/dagjson/unmarshal.go

@@ -19,11 +19,7 @@ import (
 //       several steps of handling maps, because it necessitates peeking several
 //        tokens before deciding what kind of value to create).
 
-func Unmarshal(na ipld.NodeAssembler, tokSrc shared.TokenSource) error {
-	return unmarshal(na, tokSrc, true)
-}
-
-func unmarshal(na ipld.NodeAssembler, tokSrc shared.TokenSource, parseLinks bool) error {
+func Unmarshal(na ipld.NodeAssembler, tokSrc shared.TokenSource, parseLinks bool) error {
 	var st unmarshalState
 	st.parseLinks = parseLinks
 	done, err := tokSrc.Step(&st.tk[0])

codec/json/multicodec.go

+package json
+
+import (
+	"fmt"
+	"io"
+
+	rfmtjson "github.com/polydawn/refmt/json"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	"github.com/ipld/go-ipld-prime/multicodec"
+)
+
+var (
+	_ ipld.Decoder = Decode
+	_ ipld.Encoder = Encode
+)
+
+func init() {
+	multicodec.RegisterEncoder(0x0200, Encode)
+	multicodec.RegisterDecoder(0x0200, Decode)
+}
+
+func Decode(na ipld.NodeAssembler, r io.Reader) error {
+	// Shell out directly to generic builder path.
+	//  (There's not really any fastpaths of note for json.)
+	err := dagjson.Unmarshal(na, rfmtjson.NewDecoder(r), false)
+	if err != nil {
+		return err
+	}
+	// Slurp any remaining whitespace.
+	//  (This is relevant if our reader is tee'ing bytes to a hasher, and
+	//   the json contained any trailing whitespace.)
+	//  (We can't actually support multiple objects per reader from here;
+	//   we can't unpeek if we find a non-whitespace token, so our only
+	//    option is to error if this reader seems to contain more content.)
+	var buf [1]byte
+	for {
+		_, err := r.Read(buf[:])
+		switch buf[0] {
+		case ' ', 0x0, '\t', '\r', '\n': // continue
+		default:
+			return fmt.Errorf("unexpected content after end of json object")
+		}
+		if err == nil {
+			continue
+		} else if err == io.EOF {
+			return nil
+		} else {
+			return err
+		}
+	}
+}
+
+func Encode(n ipld.Node, w io.Writer) error {
+	// Shell out directly to generic inspection path.
+	//  (There's not really any fastpaths of note for json.)
+	// Write another function if you need to tune encoding options about whitespace.
+	return dagjson.Marshal(n, rfmtjson.NewEncoder(w, rfmtjson.EncodeOptions{
+		Line:   []byte{'\n'},
+		Indent: []byte{'\t'},
+	}))
+}

schema/gen/go/testcase_test.go

@@ -190,7 +190,7 @@ func (tcase testcase) Test(t *testing.T, np, npr ipld.NodePrototype) {
 func testUnmarshal(t *testing.T, np ipld.NodePrototype, data string, expectFail error) ipld.Node {
 	t.Helper()
 	nb := np.NewBuilder()
-	err := dagjson.Unmarshal(nb, json.NewDecoder(strings.NewReader(data)))
+	err := dagjson.Unmarshal(nb, json.NewDecoder(strings.NewReader(data)), true)
 	switch {
 	case expectFail == nil && err != nil:
 		t.Fatalf("fixture parse failed: %s", err)

schema/schema2/typesystem_test.go

@@ -206,7 +206,7 @@ func testParse(t *testing.T, schemajson string, expectParseErr error, expectType
 
 func parseSchema(schemajson string) (schemadmt.Schema, error) {
 	nb := schemadmt.Type.Schema__Repr.NewBuilder()
-	if err := dagjson.Unmarshal(nb, json.NewDecoder(strings.NewReader(schemajson))); err != nil {
+	if err := dagjson.Unmarshal(nb, json.NewDecoder(strings.NewReader(schemajson)), true); err != nil {
 		return nil, err
 	}
 	return nb.Build().(schemadmt.Schema), nil