ci(spinner): add unit test for spinner (#3901)

tests/src/lv_test_init.c

@@ -72,7 +72,12 @@ static void dummy_flush_cb(lv_disp_drv_t * disp_drv, const lv_area_t * area, lv_
     LV_UNUSED(area);
     LV_UNUSED(color_p);
 
-    memcpy(test_fb, color_p, lv_area_get_size(area) * sizeof(lv_color_t));
+    for(int y = area->y1; y <= area->y2; y++) {
+        for(int x = area->x1; x <= area->x2; x++) {
+            test_fb[y * HOR_RES + x] = *color_p;
+            color_p++;
+        }
+    }
 
     lv_disp_flush_ready(disp_drv);
 }

tests/src/test_cases/test_spinner.c

@@ -0,0 +1,34 @@
+#if LV_BUILD_TEST
+#include "../lvgl.h"
+
+#include "unity/unity.h"
+
+static lv_obj_t * active_screen = NULL;
+static lv_obj_t * spinner = NULL;
+
+void setUp(void)
+{
+    active_screen = lv_scr_act();
+    spinner = lv_spinner_create(lv_scr_act(), 1000, 60);
+    lv_obj_set_size(spinner, 100, 100);
+    lv_obj_center(spinner);
+}
+
+void tearDown(void)
+{
+    lv_obj_clean(active_screen);
+}
+
+void test_spinner_spinning(void)
+{
+    for(int i = 0; i < 10; ++i) {
+        lv_tick_inc(50);
+        lv_task_handler();
+
+        char filename[15];
+        snprintf(filename, 15, "spinner_%02d.png", i);
+        TEST_ASSERT_EQUAL_SCREENSHOT(filename);
+    }
+}
+
+#endif