fix: Fixed functions of decodeJson do not return.

Author: hechenglong

response.go

@@ -237,7 +237,7 @@ func (r *Response) readAll() (err error) {
 	} else {
 		r.bodyBytes, err = ioReadAll(r.Body)
 		closeq(r.Body)
-		r.Body = &nopReadCloser{r: bytes.NewReader(r.bodyBytes)}
+		r.Body = &nopReadCloser{r: bytes.NewReader(r.bodyBytes), resetOnEOF: true}
 	}
 	if err == io.ErrUnexpectedEOF {
 		// content-encoding scenario's - empty/no response body from server
@@ -265,7 +265,7 @@ func (r *Response) wrapCopyReadCloser() {
 		f: func(b *bytes.Buffer) {
 			r.bodyBytes = append([]byte{}, b.Bytes()...)
 			closeq(r.Body)
-			r.Body = &nopReadCloser{r: bytes.NewReader(r.bodyBytes)}
+			r.Body = &nopReadCloser{r: bytes.NewReader(r.bodyBytes), resetOnEOF: true}
 			releaseBuffer(b)
 		},
 	}

stream.go

@@ -55,6 +55,30 @@ func encodeJSONEscapeHTMLIndent(w io.Writer, v any, esc bool, indent string) err
 
 func decodeJSON(r io.Reader, v any) error {
 	dec := json.NewDecoder(r)
+
+	// Handle nopReadCloser specially to support multiple JSON objects
+	// while preventing infinite loops
+	if nrc, ok := r.(*nopReadCloser); ok {
+		// Temporarily disable auto-reset to prevent infinite loops
+		originalReset := nrc.resetOnEOF
+		nrc.resetOnEOF = false
+		defer func() { nrc.resetOnEOF = originalReset }()
+
+		// Decode all JSON objects in the data
+		for {
+			if err := dec.Decode(v); err == io.EOF {
+				break
+			} else if err != nil {
+				return err
+			}
+		}
+
+		// After decoding, reset for future reads
+		nrc.Reset()
+		return nil
+	}
+
+	// For other readers, decode multiple JSON objects as intended
 	for {
 		if err := dec.Decode(v); err == io.EOF {
 			break
@@ -196,19 +220,25 @@ func (r *copyReadCloser) Close() error {
 var _ io.ReadCloser = (*nopReadCloser)(nil)
 
 type nopReadCloser struct {
-	r *bytes.Reader
+	r          *bytes.Reader
+	resetOnEOF bool // Whether to reset on EOF
 }
 
 func (r *nopReadCloser) Read(p []byte) (int, error) {
 	n, err := r.r.Read(p)
-	if err == io.EOF {
+	if err == io.EOF && r.resetOnEOF {
 		r.r.Seek(0, io.SeekStart)
 	}
 	return n, err
 }
 
 func (r *nopReadCloser) Close() error { return nil }
 
+// Reset allows manual reset of the reader position
+func (r *nopReadCloser) Reset() {
+	r.r.Seek(0, io.SeekStart)
+}
+
 var _ flate.Reader = (*nopReader)(nil)
 
 type nopReader struct{}

stream_test.go

@@ -0,0 +1,134 @@
+package resty
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestDecodeJSONWhenResponseBodyIsNull(t *testing.T) {
+	r := &Response{
+		Body: io.NopCloser(bytes.NewReader([]byte("null"))),
+	}
+	r.wrapCopyReadCloser()
+	err := r.readAll()
+	assertNil(t, err)
+
+	var result map[int]int
+	err = decodeJSON(r.Body, &result)
+	assertNil(t, err)
+	assertNil(t, result)
+}
+
+func TestGetMethodWhenResponseIsNull(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("null"))
+	}))
+
+	client := New().SetRetryCount(3).EnableGenerateCurlCmd()
+
+	var x any
+	resp, err := client.R().SetBody("{}").
+		SetHeader("Content-Type", "application/json; charset=utf-8").
+		SetForceResponseContentType("application/json").
+		SetAllowMethodGetPayload(true).
+		SetResponseBodyUnlimitedReads(true).
+		SetResult(&x).
+		Get(server.URL + "/test")
+
+	assertNil(t, err)
+	assertEqual(t, "null", resp.String())
+	assertEqual(t, nil, x)
+}
+
+func TestDecodeJSON(t *testing.T) {
+	// Test single object
+	jsonData := `{"name": "John", "age": 30}`
+	reader := bytes.NewReader([]byte(jsonData))
+	var result map[string]any
+	err := decodeJSON(reader, &result)
+	assertNil(t, err)
+	assertEqual(t, "John", result["name"])
+	assertEqual(t, float64(30), result["age"])
+
+	// Test multiple objects - should get the last one
+	multipleJSON := `{"id": 1}
+{"id": 2}
+{"id": 3}`
+	reader2 := bytes.NewReader([]byte(multipleJSON))
+	var result2 map[string]any
+	err = decodeJSON(reader2, &result2)
+	assertNil(t, err)
+	assertEqual(t, float64(3), result2["id"])
+
+	// Test malformed JSON
+	malformedJSON := `{"name": "John", "age":}`
+	reader3 := bytes.NewReader([]byte(malformedJSON))
+	var result3 map[string]any
+	err = decodeJSON(reader3, &result3)
+	assertNotNil(t, err)
+}
+
+func TestWrapCopyReadCloser(t *testing.T) {
+	testData := "Hello, World!"
+	r := &Response{
+		Body: io.NopCloser(bytes.NewReader([]byte(testData))),
+	}
+
+	// Before wrapping, bodyBytes should be empty
+	assertEqual(t, 0, len(r.bodyBytes))
+
+	r.wrapCopyReadCloser()
+
+	// Read data - should trigger copy mechanism and transform to nopReadCloser
+	data, err := io.ReadAll(r.Body)
+	assertNil(t, err)
+	assertEqual(t, testData, string(data))
+	assertEqual(t, testData, string(r.bodyBytes))
+
+	// Should now be nopReadCloser for unlimited reads
+	_, ok := r.Body.(*nopReadCloser)
+	assertEqual(t, true, ok)
+
+	// Test unlimited reads
+	data2, err := io.ReadAll(r.Body)
+	assertNil(t, err)
+	assertEqual(t, testData, string(data2))
+}
+
+func TestMultipleJSONObjectsSupport(t *testing.T) {
+	// Test multiple JSON objects with wrapCopyReadCloser
+	jsonData := `{"first": 1}
+{"second": 2}
+{"third": 3}`
+
+	r := &Response{
+		Body: io.NopCloser(bytes.NewReader([]byte(jsonData))),
+	}
+	r.wrapCopyReadCloser()
+
+	// Should process all objects and get the last one
+	var result map[string]any
+	err := decodeJSON(r.Body, &result)
+	assertNil(t, err)
+	assertEqual(t, float64(3), result["third"])
+
+	// Should support unlimited reads and decoding
+	var result2 map[string]any
+	err = decodeJSON(r.Body, &result2)
+	assertNil(t, err)
+	assertEqual(t, float64(3), result2["third"])
+
+	// Test direct nopReadCloser usage
+	nopReader := &nopReadCloser{
+		r:          bytes.NewReader([]byte(jsonData)),
+		resetOnEOF: true,
+	}
+
+	var result3 map[string]any
+	err = decodeJSON(nopReader, &result3)
+	assertNil(t, err)
+	assertEqual(t, float64(3), result3["third"])
+}