support XPath query for JSON

Author: zhengchun

html.go

@@ -48,8 +48,7 @@ func ParseMediaType(v string) MediaType {
 	}
 }
 
-// ParseHTML parses an HTTP response as HTML document.
-func ParseHTML(resp *http.Response) (*html.Node, error) {
+func readResponseBody(resp *http.Response) (io.Reader, error) {
 	var (
 		ce encoding.Encoding
 		r  io.Reader = resp.Body
@@ -83,5 +82,14 @@ func ParseHTML(resp *http.Response) (*html.Node, error) {
 	if ce != encoding.Nop {
 		r = transform.NewReader(r, ce.NewDecoder())
 	}
+	return r, nil
+}
+
+// ParseHTML parses an HTTP response as HTML document.
+func ParseHTML(resp *http.Response) (*html.Node, error) {
+	r, err := readResponseBody(resp)
+	if err != nil {
+		return nil, err
+	}
 	return htmlquery.Parse(r)
 }

json.go

@@ -0,0 +1,16 @@
+package antch
+
+import (
+	"net/http"
+
+	"github.com/antchfx/jsonquery"
+)
+
+// ParseJSON parses an HTTP response as JSON document.
+func ParseJSON(resp *http.Response) (*jsonquery.Node, error) {
+	r, err := readResponseBody(resp)
+	if err != nil {
+		return nil, err
+	}
+	return jsonquery.Parse(r)
+}

json_test.go

@@ -0,0 +1,20 @@
+package antch
+
+import (
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"testing"
+)
+
+var testJSON = `{"name":"John","age":31,"city":"New York"}`
+
+func TestParseJSON(t *testing.T) {
+	res := &http.Response{
+		Body: ioutil.NopCloser(strings.NewReader(testJSON)),
+	}
+	_, err := ParseJSON(res)
+	if err != nil {
+		t.Fatal(err)
+	}
+}