Merge pull request #193 from Mido-sys/fix_panic_unassignabile_array

Fix Panic when the underlying data type of the array differs from value

compiler.go

@@ -302,7 +302,16 @@ func (c *compiler) evalUpdateIndex(left, index, value interface{}) error {
 			if rv.Len()-1 < i {
 				err = fmt.Errorf("array index out of bounds, got index %d, while array size is %v", i, rv.Len())
 			} else {
-				rv.Index(i).Set(reflect.ValueOf(value))
+				elemType := reflect.TypeOf(left).Elem()
+				if elemType.Kind() != reflect.Interface {
+					t := reflect.ValueOf(value).Type()
+					if elemType != t {
+						err = fmt.Errorf("cannot use '%v' (untyped %s constant) as %s value in assignment", value, t, elemType)
+					}
+				}
+				if err == nil {
+					rv.Index(i).Set(reflect.ValueOf(value))
+				}
 			}
 		} else {
 			err = fmt.Errorf("can't access Slice/Array with a non int Index (%v)", index)

variables_test.go

@@ -145,6 +145,35 @@ func Test_Render_Let_Array(t *testing.T) {
 	}
 }
 
+func Test_Render_Let_ArrayAsssign_Unassignable(t *testing.T) {
+	r := require.New(t)
+	ctx := plush.NewContext()
+
+	type tt struct {
+		P string
+	}
+
+	ctx.Set("myArray", []tt{tt{P: "t"}})
+	input := `<p><% let a = myArray %></p><% a[0] = "HELLO WORLD" %>`
+	_, err := plush.Render(input, ctx)
+	r.Error(err)
+	r.Contains(err.Error(), "cannot use 'HELLO WORLD' (untyped string constant) as plush_test.tt value in assignment")
+}
+
+func Test_Render_Let_ArrayAsssign_AssignableToArrayInterface(t *testing.T) {
+	r := require.New(t)
+	ctx := plush.NewContext()
+
+	type tt struct {
+		P string
+	}
+
+	ctx.Set("myArray", []interface{}{tt{P: "t"}, tt{P: "g"}})
+	input := `<p><% let a = myArray %></p><% a[0] = "HELLO WORLD" %>`
+	_, err := plush.Render(input, ctx)
+	r.NoError(err)
+}
+
 type Category1 struct {
 	Products []Product1
 }