Add unit tests for control event serialization

Test serialization of the 4 types of events (keycode, text, mouse,
scroll).

app/meson.build

@@ -35,6 +35,7 @@ executable('scrcpy', src, dependencies: dependencies)
 
 tests = [
     ['test_control_event_queue', ['tests/test_control_event_queue.c', 'src/controlevent.c']],
+    ['test_control_event_serialize', ['tests/test_control_event_serialize.c', 'src/controlevent.c']],
     ['test_strutil', ['tests/test_strutil.c', 'src/strutil.c']],
 ]
 

app/tests/test_control_event_serialize.c

@@ -0,0 +1,104 @@
+#include <assert.h>
+
+#include "controlevent.h"
+
+static void test_serialize_keycode_event() {
+    struct control_event event = {
+        .type = CONTROL_EVENT_TYPE_KEYCODE,
+        .keycode_event = {
+            .action = AKEY_EVENT_ACTION_UP,
+            .keycode = AKEYCODE_ENTER,
+            .metastate = AMETA_SHIFT_ON | AMETA_SHIFT_LEFT_ON,
+        },
+    };
+
+    unsigned char buf[SERIALIZED_EVENT_MAX_SIZE];
+    int size = control_event_serialize(&event, buf);
+    assert(size == 10);
+
+    const unsigned char expected[] = {
+        0x00, // CONTROL_EVENT_TYPE_KEYCODE
+        0x01, // AKEY_EVENT_ACTION_UP
+        0x00, 0x00, 0x00, 0x42, // AKEYCODE_ENTER
+        0x00, 0x00, 0x00, 0x41, // AMETA_SHIFT_ON | AMETA_SHIFT_LEFT_ON
+    };
+    assert(!memcmp(buf, expected, sizeof(expected)));
+}
+
+static void test_serialize_text_event() {
+    struct control_event event = {
+        .type = CONTROL_EVENT_TYPE_TEXT,
+        .text_event = {
+            .text = "hello, world!",
+        },
+    };
+
+    unsigned char buf[SERIALIZED_EVENT_MAX_SIZE];
+    int size = control_event_serialize(&event, buf);
+    assert(size == 15);
+
+    const unsigned char expected[] = {
+        0x01, // CONTROL_EVENT_TYPE_KEYCODE
+        0x0d, // text length
+        'h', 'e', 'l', 'l', 'o', ',', ' ', 'w', 'o', 'r', 'l', 'd', '!', // text
+    };
+    assert(!memcmp(buf, expected, sizeof(expected)));
+}
+
+static void test_serialize_mouse_event() {
+    struct control_event event = {
+        .type = CONTROL_EVENT_TYPE_MOUSE,
+        .mouse_event = {
+            .action = AMOTION_EVENT_ACTION_DOWN,
+            .buttons = AMOTION_EVENT_BUTTON_PRIMARY,
+            .x = 260,
+            .y = 1026,
+        },
+    };
+
+    unsigned char buf[SERIALIZED_EVENT_MAX_SIZE];
+    int size = control_event_serialize(&event, buf);
+    assert(size == 14);
+
+    const unsigned char expected[] = {
+        0x02, // CONTROL_EVENT_TYPE_MOUSE
+        0x00, // AKEY_EVENT_ACTION_DOWN
+        0x00, 0x00, 0x00, 0x01, // AMOTION_EVENT_BUTTON_PRIMARY
+        0x00, 0x00, 0x01, 0x04, // 260
+        0x00, 0x00, 0x04, 0x02, // 1026
+    };
+    assert(!memcmp(buf, expected, sizeof(expected)));
+}
+
+static void test_serialize_scroll_event() {
+    struct control_event event = {
+        .type = CONTROL_EVENT_TYPE_SCROLL,
+        .scroll_event = {
+            .x = 260,
+            .y = 1026,
+            .hscroll = 1,
+            .vscroll = -1,
+        },
+    };
+
+    unsigned char buf[SERIALIZED_EVENT_MAX_SIZE];
+    int size = control_event_serialize(&event, buf);
+    assert(size == 17);
+
+    const unsigned char expected[] = {
+        0x03, // CONTROL_EVENT_TYPE_SCROLL
+        0x00, 0x00, 0x01, 0x04, // 260
+        0x00, 0x00, 0x04, 0x02, // 1026
+        0x00, 0x00, 0x00, 0x01, // 1
+        0xFF, 0xFF, 0xFF, 0xFF, // -1
+    };
+    assert(!memcmp(buf, expected, sizeof(expected)));
+}
+
+int main() {
+    test_serialize_keycode_event();
+    test_serialize_text_event();
+    test_serialize_mouse_event();
+    test_serialize_scroll_event();
+    return 0;
+}