Add json handlers (#93)

* Add json marshaler/unmarshaler helpers
* Add json test cases

version.go

@@ -2,6 +2,7 @@ package version
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"reflect"
 	"regexp"
@@ -388,3 +389,26 @@ func (v *Version) String() string {
 func (v *Version) Original() string {
 	return v.original
 }
+
+// UnmarshalJSON implements JSON.Unmarshaler interface.
+func (v *Version) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	temp, err := NewVersion(s)
+	if err != nil {
+		return err
+	}
+	v.metadata = temp.metadata
+	v.pre = temp.pre
+	v.segments = temp.segments
+	v.si = temp.si
+	v.original = temp.original
+	return nil
+}
+
+// MarshalJSON implements JSON.Marshaler interface.
+func (v Version) MarshalJSON() ([]byte, error) {
+	return json.Marshal(v.String())
+}

version_test.go

@@ -1,6 +1,8 @@
 package version
 
 import (
+	"encoding/json"
+	"fmt"
 	"reflect"
 	"testing"
 )
@@ -21,13 +23,13 @@ func TestNewVersion(t *testing.T) {
 		{"1.2-beta.5", false},
 		{"\n1.2", true},
 		{"1.2.0-x.Y.0+metadata", false},
-		{"1.2.0-x.Y.0+metadata-width-hypen", false},
-		{"1.2.3-rc1-with-hypen", false},
+		{"1.2.0-x.Y.0+metadata-width-hyphen", false},
+		{"1.2.3-rc1-with-hyphen", false},
 		{"1.2.3.4", false},
 		{"1.2.0.4-x.Y.0+metadata", false},
-		{"1.2.0.4-x.Y.0+metadata-width-hypen", false},
+		{"1.2.0.4-x.Y.0+metadata-width-hyphen", false},
 		{"1.2.0-X-1.2.0+metadata~dist", false},
-		{"1.2.3.4-rc1-with-hypen", false},
+		{"1.2.3.4-rc1-with-hyphen", false},
 		{"1.2.3.4", false},
 		{"v1.2.3", false},
 		{"foo1.2.3", true},
@@ -62,13 +64,13 @@ func TestNewSemver(t *testing.T) {
 		{"1.2-beta.5", false},
 		{"\n1.2", true},
 		{"1.2.0-x.Y.0+metadata", false},
-		{"1.2.0-x.Y.0+metadata-width-hypen", false},
-		{"1.2.3-rc1-with-hypen", false},
+		{"1.2.0-x.Y.0+metadata-width-hyphen", false},
+		{"1.2.3-rc1-with-hyphen", false},
 		{"1.2.3.4", false},
 		{"1.2.0.4-x.Y.0+metadata", false},
-		{"1.2.0.4-x.Y.0+metadata-width-hypen", false},
+		{"1.2.0.4-x.Y.0+metadata-width-hyphen", false},
 		{"1.2.0-X-1.2.0+metadata~dist", false},
-		{"1.2.3.4-rc1-with-hypen", false},
+		{"1.2.3.4-rc1-with-hyphen", false},
 		{"1.2.3.4", false},
 		{"v1.2.3", false},
 		{"foo1.2.3", true},
@@ -393,6 +395,75 @@ func TestVersionSegments64(t *testing.T) {
 	}
 }
 
+func TestJsonMarshal(t *testing.T) {
+	cases := []struct {
+		version string
+		err     bool
+	}{
+		{"1.2.3", false},
+		{"1.2.0-x.Y.0+metadata", false},
+		{"1.2.0-x.Y.0+metadata-width-hyphen", false},
+		{"1.2.3-rc1-with-hyphen", false},
+		{"1.2.3.4", false},
+		{"1.2.0.4-x.Y.0+metadata", false},
+		{"1.2.0.4-x.Y.0+metadata-width-hyphen", false},
+		{"1.2.0-X-1.2.0+metadata~dist", false},
+		{"1.2.3.4-rc1-with-hyphen", false},
+		{"1.2.3.4", false},
+	}
+
+	for _, tc := range cases {
+		v, err1 := NewVersion(tc.version)
+		if err1 != nil {
+			t.Fatalf("error for version %q: %s", tc.version, err1)
+		}
+
+		parsed, err2 := json.Marshal(v)
+		if err2 != nil {
+			t.Fatalf("error marshaling version %q: %s", tc.version, err2)
+		}
+		result := string(parsed)
+		expected := fmt.Sprintf("%q", tc.version)
+		if result != expected && !tc.err {
+			t.Fatalf("Error marshaling unexpected marshaled content: result=%q expected=%q", result, expected)
+		}
+	}
+}
+
+func TestJsonUnmarshal(t *testing.T) {
+	cases := []struct {
+		version string
+		err     bool
+	}{
+		{"1.2.3", false},
+		{"1.2.0-x.Y.0+metadata", false},
+		{"1.2.0-x.Y.0+metadata-width-hyphen", false},
+		{"1.2.3-rc1-with-hyphen", false},
+		{"1.2.3.4", false},
+		{"1.2.0.4-x.Y.0+metadata", false},
+		{"1.2.0.4-x.Y.0+metadata-width-hyphen", false},
+		{"1.2.0-X-1.2.0+metadata~dist", false},
+		{"1.2.3.4-rc1-with-hyphen", false},
+		{"1.2.3.4", false},
+	}
+
+	for _, tc := range cases {
+		expected, err1 := NewVersion(tc.version)
+		if err1 != nil {
+			t.Fatalf("err: %s", err1)
+		}
+
+		actual := &Version{}
+		err2 := json.Unmarshal([]byte(fmt.Sprintf("%q", tc.version)), actual)
+		if err2 != nil {
+			t.Fatalf("error unmarshaling version: %s", err2)
+		}
+		if !reflect.DeepEqual(actual, expected) {
+			t.Fatalf("error unmarshaling, unexpected object content: actual=%q expected=%q", actual, expected)
+		}
+	}
+}
+
 func TestVersionString(t *testing.T) {
 	cases := [][]string{
 		{"1.2.3", "1.2.3"},