simplify digest_pad_combinations

Author: newpavlov

block-buffer/tests/mod.rs

@@ -95,35 +95,18 @@ fn digest_pad_combinations() {
 
             buf.digest_blocks(data, |_| panic!("should not be called"));
 
-            let mut n = 0;
-            buf.digest_pad(delim, suffix, |block| {
-                match n {
-                    0 => {
-                        assert!(block.starts_with(data));
-                        assert_eq!(block[data_len], delim);
-
-                        let tail = &block[data_len + 1..];
-                        if tail.len() >= suffix_len {
-                            assert!(data.len() + suffix.len() < block.len());
-
-                            let (l, r) = tail.split_at(tail.len() - suffix_len);
-                            assert!(l.iter().all(|b| *b == 0));
-                            assert_eq!(r, suffix);
-                        } else {
-                            assert!(tail.iter().all(|b| *b == 0));
-                        }
-                    }
-                    1 => {
-                        assert!(data.len() + suffix.len() >= block.len());
-                        let (l, r) = block.split_at(block.len() - suffix_len);
-                        assert!(l.iter().all(|b| *b == 0));
-                        assert_eq!(r, suffix);
-                    }
-                    _ => unreachable!(),
-                }
-                n += 1;
-            });
+            let mut accum = Vec::with_capacity(2 * buf.size());
+            buf.digest_pad(delim, suffix, |block| accum.extend_from_slice(block));
+
+            assert!(accum.len() <= 2 * buf.size());
             assert_eq!(buf.get_pos(), 0);
+
+            let (res_data, rem) = accum.split_at(data_len);
+            let (res_zeros, res_suffix) = rem.split_at(rem.len() - suffix_len);
+
+            assert_eq!(res_data, data);
+            assert!(res_zeros.iter().all(|&b| b == 0));
+            assert_eq!(res_suffix, suffix);
         }
     }
 }