impl Stringer for struct and typed values

Author: loongy

Diff for: struct.go

@@ -143,6 +143,15 @@ func (v Struct) MarshalJSON() ([]byte, error) {
 	return json.Marshal(raw)
 }
 
+// String returns the struct in its JSON representation.
+func (v Struct) String() string {
+	data, err := v.MarshalJSON()
+	if err != nil {
+		return fmt.Sprintf(`{"error": %v}`, err)
+	}
+	return string(data)
+}
+
 // Generate a random struct field. This method is implemented for use in quick
 // tests. See https://golang.org/pkg/testing/quick/#Generator for more
 // information. Generated structs will never contain embedded structs.

Diff for: struct_test.go

@@ -2,6 +2,7 @@ package pack_test
 
 import (
 	"reflect"
+	"testing/quick"
 
 	"github.com/renproject/pack"
 	"github.com/renproject/pack/packutil"
@@ -84,9 +85,24 @@ var _ = Describe("Struct", func() {
 
 	Context("when getting type information", func() {
 		It("should return the struct type", func() {
-			s := pack.NewStruct("foo", pack.NewU64(32))
-			t := s.Type()
-			Expect(t.Kind()).To(Equal(pack.KindStruct))
+			f := func(x pack.Struct) bool {
+				Expect(x.Type().Kind()).To(Equal(pack.KindStruct))
+				return true
+			}
+			Expect(quick.Check(f, nil)).To(Succeed())
+		})
+	})
+
+	Context("when stringifying a struct", func() {
+		It("should equal the JSON representation", func() {
+			f := func(x pack.Struct) bool {
+				stringified := x.String()
+				data, err := x.MarshalJSON()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(stringified).To(Equal(string(data)))
+				return true
+			}
+			Expect(quick.Check(f, nil)).To(Succeed())
 		})
 	})
 })

Diff for: value.go

@@ -129,6 +129,15 @@ func (typed *Typed) Unmarshal(buf []byte, rem int) ([]byte, int, error) {
 	return buf, rem, nil
 }
 
+// String returns the struct in its JSON representation.
+func (typed Typed) String() string {
+	data, err := typed.MarshalJSON()
+	if err != nil {
+		return fmt.Sprintf(`{"error": %v}`, err)
+	}
+	return string(data)
+}
+
 // Generate a random well-typed struct. This method is implemented for use in
 // quick tests. See https://golang.org/pkg/testing/quick/#Generator for more
 // information. Generated typed values will never contain embedded structs.

Diff for: value_test.go

@@ -2,6 +2,7 @@ package pack_test
 
 import (
 	"reflect"
+	"testing/quick"
 
 	"github.com/renproject/pack"
 	"github.com/renproject/pack/packutil"
@@ -72,9 +73,24 @@ var _ = Describe("Typed", func() {
 
 	Context("when getting type information", func() {
 		It("should return the struct type", func() {
-			s := pack.NewTyped("foo", pack.NewU64(32))
-			t := s.Type()
-			Expect(t.Kind()).To(Equal(pack.KindStruct))
+			f := func(x pack.Typed) bool {
+				Expect(x.Type().Kind()).To(Equal(pack.KindStruct))
+				return true
+			}
+			Expect(quick.Check(f, nil)).To(Succeed())
+		})
+	})
+
+	Context("when stringifying a typed struct", func() {
+		It("should equal the JSON representation", func() {
+			f := func(x pack.Typed) bool {
+				stringified := x.String()
+				data, err := x.MarshalJSON()
+				Expect(err).ToNot(HaveOccurred())
+				Expect(stringified).To(Equal(string(data)))
+				return true
+			}
+			Expect(quick.Check(f, nil)).To(Succeed())
 		})
 	})
 })