fix: issue 3840 (#3845)

core/mapping/unmarshaler.go

@@ -625,7 +625,12 @@ func (u *Unmarshaler) processFieldPrimitiveWithJSONNumber(fieldType reflect.Type
 			return err
 		}
 
-		if value.OverflowFloat(fValue) {
+		// if value is a pointer, we need to check overflow with the pointer's value.
+		overflowValidator := value
+		if overflowValidator.Type().Kind() == reflect.Ptr {
+			overflowValidator = overflowValidator.Elem()
+		}
+		if overflowValidator.OverflowFloat(fValue) {
 			return fmt.Errorf("parsing %q as float32: value out of range", v.String())
 		}
 

core/mapping/unmarshaler_test.go

@@ -1339,8 +1339,20 @@ func TestUnmarshalNullableSlice(t *testing.T) {
 		"slice": `[null,2]`,
 	}
 
-	ast := assert.New(t)
-	ast.Equal(UnmarshalKey(m, &v), errNilSliceElement)
+	assert.New(t).Equal(UnmarshalKey(m, &v), errNilSliceElement)
+}
+
+func TestUnmarshalWithFloatPtr(t *testing.T) {
+	var v struct {
+		WeightFloat32 *float32 `key:"weightFloat32,optional"`
+	}
+	m := map[string]any{
+		"weightFloat32": json.Number("3.2"),
+	}
+
+	if assert.NoError(t, UnmarshalKey(m, &v)) {
+		assert.Equal(t, float32(3.2), *v.WeightFloat32)
+	}
 }
 
 func TestUnmarshalIntSlice(t *testing.T) {

rest/httpx/requests_test.go

@@ -395,6 +395,21 @@ func TestParsePathWithDot(t *testing.T) {
 	assert.Equal(t, 18, v.Age)
 }
 
+func TestParseWithFloatPtr(t *testing.T) {
+	t.Run("has float32 pointer", func(t *testing.T) {
+		var v struct {
+			WeightFloat32 *float32 `json:"weightFloat32,optional"`
+		}
+		body := `{"weightFloat32": 3.2}`
+		r := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(body))
+		r.Header.Set(ContentType, header.JsonContentType)
+
+		if assert.NoError(t, Parse(r, &v)) {
+			assert.Equal(t, float32(3.2), *v.WeightFloat32)
+		}
+	})
+}
+
 func BenchmarkParseRaw(b *testing.B) {
 	r, err := http.NewRequest(http.MethodGet, "http://hello.com/a?name=hello&age=18&percent=3.4", http.NoBody)
 	if err != nil {