make field length optional for maps (#97)

.travis.yml

@@ -1,12 +1,15 @@
 language: go
 go_import_path: github.com/centrifuge/precise-proofs
 go:
- - 1.11.x
- - tip
+ - 1.15.x
+
+env:
+ matrix:
+  - GO111MODULE=on
 
 install:
-  - go get -u github.com/golang/dep/...
-  - dep ensure
+  - go mod tidy
+  - go mod vendor
 
 script:
   - go test -race -coverprofile=coverage.txt -covermode=atomic -v ./proofs

examples/wasm/main.go

@@ -1,3 +1,5 @@
+// +build wasm
+
 package main
 
 import (
@@ -7,9 +9,9 @@ import (
 	"strings"
 	"syscall/js"
 
-	"github.com/centrifuge/precise-proofs/examples/documents"
+	documentspb "github.com/centrifuge/precise-proofs/examples/documents"
 	"github.com/centrifuge/precise-proofs/proofs"
-	"github.com/centrifuge/precise-proofs/proofs/proto"
+	proofspb "github.com/centrifuge/precise-proofs/proofs/proto"
 	"github.com/golang/protobuf/jsonpb"
 )
 

go.mod

@@ -0,0 +1,16 @@
+module github.com/centrifuge/precise-proofs
+
+go 1.15
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/golang/protobuf v1.3.1
+	github.com/pkg/errors v0.8.0
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.2.2
+	github.com/xsleonard/go-merkle v1.1.0
+	golang.org/x/crypto v0.0.0-20190530122614-20be4c3c3ed5
+	golang.org/x/sys v0.0.0-20190531073156-46560c3f3c0a // indirect
+)
+
+replace github.com/xsleonard/go-merkle v1.1.0 => github.com/centrifuge/go-merkle v0.0.0-20190727075423-0ac78bbbc01b

go.sum

@@ -0,0 +1,21 @@
+github.com/centrifuge/go-merkle v0.0.0-20190727075423-0ac78bbbc01b h1:TPvvMcGAc3TVBVgQ4XYYEWTXxYls8YuylZ8JzrVxPzc=
+github.com/centrifuge/go-merkle v0.0.0-20190727075423-0ac78bbbc01b/go.mod h1:0voJY6Qzxvr2S0LeDSFQiCnJzGq5gORg2SwCmn8602I=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
+github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190530122614-20be4c3c3ed5 h1:8dUaAV7K4uHsF56JQWkprecIQKdPHtR9jCHF5nB8uzc=
+golang.org/x/crypto v0.0.0-20190530122614-20be4c3c3ed5/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190531073156-46560c3f3c0a h1:ndj5BW7+tkr8XVsbkZpft/pgCRU+L76ePImF2dpCwek=
+golang.org/x/sys v0.0.0-20190531073156-46560c3f3c0a/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

proofs/flatten.go

@@ -8,7 +8,7 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/centrifuge/precise-proofs/proofs/proto"
+	proofspb "github.com/centrifuge/precise-proofs/proofs/proto"
 	"github.com/golang/protobuf/descriptor"
 	"github.com/golang/protobuf/proto"
 	godescriptor "github.com/golang/protobuf/protoc-gen-go/descriptor"
@@ -254,7 +254,9 @@ func (f *messageFlattener) handleValue(prop Property, value reflect.Value, salts
 		// Handle each value of the map
 		for _, k := range value.MapKeys() {
 			keyLength := getKeyLengthFrom(outerFieldDescriptor)
-
+			if keyLength == 0 {
+				keyLength = fetchLengthFromInterface(k)
+			}
 			elemProp, err := prop.MapElemProp(k.Interface(), keyLength)
 			if err != nil {
 				return errors.Wrapf(err, "failed to create elem prop for %q", k)
@@ -296,6 +298,18 @@ func (f *messageFlattener) handleValue(prop Property, value reflect.Value, salts
 	return nil
 }
 
+func fetchLengthFromInterface(k reflect.Value) uint64 {
+	switch k.Kind() {
+	case reflect.Interface:
+		v := reflect.ValueOf(k.Interface())
+		return fetchLengthFromInterface(v)
+	case reflect.Array, reflect.Slice, reflect.String, reflect.Chan, reflect.Map:
+		return uint64(k.Len())
+	}
+
+	return 0
+}
+
 func (f *messageFlattener) appendLeaf(prop Property, value []byte, salt []byte, readablePropertyLengthSuffix string, hash []byte, hashed bool) {
 	leaf := LeafNode{
 		Property: prop,
@@ -429,13 +443,31 @@ func sliceToMap(value reflect.Value, mappingKey string, keyLength uint64) (refle
 		// since we know the key length, we convert each
 		// []byte to [keyLength]byte before using it as a key
 		keyType = reflect.ArrayOf(int(keyLength), reflect.TypeOf(byte(0)))
+
+		// if key length is 0
+		// then we set the map type as interface{}
+		// individual key type will b declared based on the length of each value
+		if keyLength == 0 {
+			m := make(map[interface{}]bool)
+			r := reflect.TypeOf(m)
+			keyType = r.Key()
+		}
+
 		extractKeyByteSlice := extractKey
 		extractKey = func(v reflect.Value) (reflect.Value, error) {
 			bs, _ := extractKeyByteSlice(v)
-			if uint64(bs.Len()) != keyLength {
+			// if key length is not set or 0,
+			// then take the key length of key
+			kt := keyType
+			if keyLength == 0 {
+				kt = reflect.ArrayOf(int(uint64(bs.Len())), reflect.TypeOf(byte(0)))
+			}
+
+			if keyLength != 0 && uint64(bs.Len()) != keyLength {
 				return reflect.Value{}, errors.Errorf("could not use %x as mapping_key - does not have length %d", bs, keyLength)
 			}
-			ba := reflect.New(keyType)
+
+			ba := reflect.New(kt)
 			reflect.Copy(ba.Elem(), bs)
 			return ba.Elem(), nil
 		}

proofs/property.go

@@ -10,9 +10,8 @@ import (
 	"strconv"
 	"strings"
 
+	proofspb "github.com/centrifuge/precise-proofs/proofs/proto"
 	"github.com/pkg/errors"
-
-	"github.com/centrifuge/precise-proofs/proofs/proto"
 )
 
 // Property uniquely identifies a LeafNode