Improve test coverage from slice_buffer

test/core/support/slice_buffer_test.c

@@ -35,13 +35,12 @@
 #include <grpc/support/slice_buffer.h>
 #include "test/core/util/test_config.h"
 
-int main(int argc, char **argv) {
+void test_slice_buffer_add() {
   gpr_slice_buffer buf;
   gpr_slice aaa = gpr_slice_from_copied_string("aaa");
   gpr_slice bb = gpr_slice_from_copied_string("bb");
   size_t i;
 
-  grpc_test_init(argc, argv);
   gpr_slice_buffer_init(&buf);
   for (i = 0; i < 10; i++) {
     gpr_slice_ref(aaa);
@@ -70,6 +69,61 @@ int main(int argc, char **argv) {
   GPR_ASSERT(buf.count == 0);
   GPR_ASSERT(buf.length == 0);
   gpr_slice_buffer_destroy(&buf);
+}
+
+void test_slice_buffer_move_first() {
+  gpr_slice slices[3];
+  gpr_slice_buffer src;
+  gpr_slice_buffer dst;
+  int idx = 0;
+  size_t src_len = 0;
+  size_t dst_len = 0;
+
+  slices[0] = gpr_slice_from_copied_string("aaa");
+  slices[1] = gpr_slice_from_copied_string("bbbb");
+  slices[2] = gpr_slice_from_copied_string("ccc");
+
+  gpr_slice_buffer_init(&src);
+  gpr_slice_buffer_init(&dst);
+  for (idx = 0; idx < 3; idx++) {
+    gpr_slice_ref(slices[idx]);
+    /* For this test, it is important that we add each slice at a new
+       slice index */
+    gpr_slice_buffer_add_indexed(&src, slices[idx]);
+    gpr_slice_buffer_add_indexed(&dst, slices[idx]);
+  }
+
+  /* Case 1: Move more than the first slice's length from src to dst */
+  src_len = src.length;
+  dst_len = dst.length;
+  gpr_slice_buffer_move_first(&src, 4, &dst);
+  src_len -= 4;
+  dst_len += 4;
+  GPR_ASSERT(src.length == src_len);
+  GPR_ASSERT(dst.length == dst_len);
+
+  /* src now has two slices ["bb"] and  ["cccc"] */
+  /* Case 2: Move the first slice from src to dst */
+  gpr_slice_buffer_move_first(&src, 3, &dst);
+  src_len -= 3;
+  dst_len += 3;
+  GPR_ASSERT(src.length == src_len);
+  GPR_ASSERT(dst.length == dst_len);
+
+  /* src now has one slice ["ccc"] */
+  /* Case 3: Move less than the first slice's length from src to dst*/
+  gpr_slice_buffer_move_first(&src, 2, &dst);
+  src_len -= 2;
+  dst_len += 2;
+  GPR_ASSERT(src.length == src.length);
+  GPR_ASSERT(dst.length == dst.length);
+}
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+
+  test_slice_buffer_add();
+  test_slice_buffer_move_first();
 
   return 0;
 }