diff -r 2ff6e9184468 -r cb9b9739055e test/test_buffer.cpp
--- a/test/test_buffer.cpp	Sun Apr 24 17:45:09 2022 +0200
+++ b/test/test_buffer.cpp	Sat Apr 30 08:30:51 2022 +0200
@@ -242,3 +242,20 @@
     cxBufferDestroy(&buf);
     EXPECT_TRUE(alloc.verify());
 }
+
+TEST(BufferClear, Test) {
+    char space[16];
+    strcpy(space, "clear test");
+    CxBuffer buf;
+    cxBufferInit(&buf, space, 16, cxDefaultAllocator, CX_BUFFER_DEFAULT);
+    ASSERT_EQ(buf.size, 0);
+    // only clear the used part of the buffer
+    cxBufferClear(&buf);
+    EXPECT_EQ(memcmp(space, "clear test", 10), 0);
+    buf.size = 5;
+    buf.pos = 3;
+    cxBufferClear(&buf);
+    EXPECT_EQ(memcmp(space, "\0\0\0\0\0 test", 10), 0);
+    EXPECT_EQ(buf.size, 0);
+    EXPECT_EQ(buf.pos, 0);
+}