Merge branch 'fix/PRXS-2770-DecodeNilMap' into 'master'

Исправлена ошибка "panic: runtime error: invalid memory address or nil pointer dereference" при вызове UnmarshalJSON при передаче "null"

See merge request perxis/perxis-go!306

pkg/schema/schema_json.go

@@ -29,6 +29,11 @@ func (s *Schema) UnmarshalJSON(b []byte) error {
 	if err := jsoniter.Unmarshal(b, &j); err != nil {
 		return errors.Wrapf(err, "error unmarshal json into field")
 	}
+
+	if j == nil {
+		return nil
+	}
+
 	s.Loaded = j.Loaded
 	s.Metadata = j.Metadata
 

pkg/schema/schema_json_test.go

+package schema
+
+import (
+	"testing"
+
+	"git.perx.ru/perxis/perxis-go/pkg/schema/field"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSchema_UnmarshalJSON(t *testing.T) {
+	s := `{
+    "ui": {
+        "options": {
+            "fields": [
+                "text"
+            ]
+        }
+    },
+    "type": "object",
+    "params": {
+        "inline": false,
+        "fields": {
+            "text": {
+                "title": "text",
+                "ui": {
+                    "widget": "StringInput"
+                },
+                "type": "string",
+                "params": {}
+            }
+        }
+    },
+    "loaded": false,
+    "metadata": null
+}`
+	tests := []struct {
+		name    string
+		b       []byte
+		want    *Schema
+		wantErr bool
+	}{
+		{
+			name:    "No panic with 'null' value in b",
+			b:       []byte("null"),
+			want:    New(),
+			wantErr: false,
+		},
+		{
+			name:    "UnmarshalJSON error #1",
+			b:       []byte(""),
+			want:    New(),
+			wantErr: true,
+		},
+		{
+			name:    "UnmarshalJSON error #2",
+			b:       []byte("abc"),
+			want:    New(),
+			wantErr: true,
+		},
+		{
+			name:    "OK",
+			b:       []byte(s),
+			want:    New("text", field.String().SetTitle("text").WithUI(&field.UI{Widget: "StringInput"})),
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			schema := New()
+			if err := schema.UnmarshalJSON(tt.b); (err != nil) != tt.wantErr {
+				t.Errorf("UnmarshalJSON() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			assert.Equal(t, tt.want, schema)
+		})
+	}
+}