feat(json): add option to write json in multiline mode (#213)

Signed-off-by: DmitriyLewen <dmitriy.lewen@smartforce.io>

examples/9-tvtojson/exampletvtojson.go

@@ -56,8 +56,16 @@ func main() {
 	}
 	defer w.Close()
 
+	var opt []json.WriteOption
+	// you can use WriteOption to change JSON format
+	// uncomment the following code to test it
+	/*
+		opt = append(opt, json.Indent(" "))      // to create multiline json
+		opt = append(opt, json.EscapeHTML(true)) // to escape HTML characters
+	*/
+
 	// try to save the document to disk as JSON file
-	err = json.Write(doc, w)
+	err = json.Write(doc, w, opt...)
 	if err != nil {
 		fmt.Printf("Error while saving %v: %v", fileOut, err)
 		return

json/writer.go

@@ -9,17 +9,25 @@ import (
 	"github.com/spdx/tools-golang/spdx/common"
 )
 
-// Write takes an SPDX Document and an io.Writer, and writes the document to the writer in JSON format.
-func Write(doc common.AnyDocument, w io.Writer) error {
-	buf, err := json.Marshal(doc)
-	if err != nil {
-		return err
+type WriteOption func(*json.Encoder)
+
+func Indent(indent string) WriteOption {
+	return func(e *json.Encoder) {
+		e.SetIndent("", indent)
 	}
+}
 
-	_, err = w.Write(buf)
-	if err != nil {
-		return err
+func EscapeHTML(escape bool) WriteOption {
+	return func(e *json.Encoder) {
+		e.SetEscapeHTML(escape)
 	}
+}
 
-	return nil
+// Write takes an SPDX Document and an io.Writer, and writes the document to the writer in JSON format.
+func Write(doc common.AnyDocument, w io.Writer, opts ...WriteOption) error {
+	e := json.NewEncoder(w)
+	for _, opt := range opts {
+		opt(e)
+	}
+	return e.Encode(doc)
 }

json/writer_test.go

@@ -0,0 +1,82 @@
+package json_test
+
+import (
+	"bytes"
+	"github.com/spdx/tools-golang/json"
+	"github.com/spdx/tools-golang/spdx/common"
+	spdx "github.com/spdx/tools-golang/spdx/v2/v2_3"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func Test_Write(t *testing.T) {
+	tests := []struct {
+		name   string
+		doc    common.AnyDocument
+		option []json.WriteOption
+		want   string
+	}{
+		{
+			name: "happy path",
+			doc: spdx.Document{
+				SPDXVersion:  "2.3",
+				DocumentName: "test_doc",
+			},
+			want: `{"spdxVersion":"2.3","dataLicense":"","SPDXID":"SPDXRef-","name":"test_doc","documentNamespace":"","creationInfo":null}
+`,
+		},
+		{
+			name: "happy path with Indent option",
+			doc: spdx.Document{
+				SPDXVersion:  "2.3",
+				DocumentName: "test_doc",
+			},
+			option: []json.WriteOption{json.Indent(" ")},
+			want: `{
+ "spdxVersion": "2.3",
+ "dataLicense": "",
+ "SPDXID": "SPDXRef-",
+ "name": "test_doc",
+ "documentNamespace": "",
+ "creationInfo": null
+}
+`,
+		},
+		{
+			name: "happy path with EscapeHTML==true option",
+			doc: spdx.Document{
+				SPDXVersion:  "2.3",
+				DocumentName: "test_doc_>",
+			},
+			option: []json.WriteOption{json.EscapeHTML(true)},
+			want:   "{\"spdxVersion\":\"2.3\",\"dataLicense\":\"\",\"SPDXID\":\"SPDXRef-\",\"name\":\"test_doc_\\u003e\",\"documentNamespace\":\"\",\"creationInfo\":null}\n",
+		},
+		{
+			name: "happy path with EscapeHTML==false option",
+			doc: spdx.Document{
+				SPDXVersion:  "2.3",
+				DocumentName: "test_doc_>",
+			},
+			option: []json.WriteOption{json.EscapeHTML(false)},
+			want:   "{\"spdxVersion\":\"2.3\",\"dataLicense\":\"\",\"SPDXID\":\"SPDXRef-\",\"name\":\"test_doc_>\",\"documentNamespace\":\"\",\"creationInfo\":null}\n",
+		},
+		{
+			name: "happy path with EscapeHTML==false option",
+			doc: spdx.Document{
+				SPDXVersion:  "2.3",
+				DocumentName: "test_doc_>",
+			},
+			option: []json.WriteOption{json.EscapeHTML(false)},
+			want:   "{\"spdxVersion\":\"2.3\",\"dataLicense\":\"\",\"SPDXID\":\"SPDXRef-\",\"name\":\"test_doc_>\",\"documentNamespace\":\"\",\"creationInfo\":null}\n",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buf := new(bytes.Buffer)
+			err := json.Write(tt.doc, buf, tt.option...)
+			assert.NoError(t, err)
+			assert.Equal(t, tt.want, buf.String())
+		})
+	}
+}