Merge rust-bitcoin/rust-bitcoin#4217: primitives: Increase test coverage in `block.rs`

c1ea20b958 Increase test coverage in block.rs (Jamil Lambert, PhD)
3e750d7ba1 Create test helper function to create a header (Jamil Lambert, PhD)

Pull request description:

  Add tests to `primitive::block` module to increase test coverage.

  Coverage tested with `cargo-tarpaulin`

  `block.rs` coverage:
  before 13.79%
  after 100%

ACKs for top commit:
  apoelstra:
    ACK c1ea20b958f448a5a35073ce3d5bd5394918eb9b; successfully ran local tests
  tcharding:
    ACK c1ea20b958

Tree-SHA512: 70bbdce9c45e9bdcea76026b7a27582a32b796099329c429527d7dfe574788604020e53e417afd3cf53886ceb87df37b6dcb34a7ff40260b9d8a3811e22a478c

primitives/src/block.rs

@@ -361,6 +361,17 @@ impl<'a> Arbitrary<'a> for Version {
 mod tests {
     use super::*;
 
+    fn dummy_header() -> Header {
+        Header {
+            version: Version::ONE,
+            prev_blockhash: BlockHash::from_byte_array([0x99; 32]),
+            merkle_root: TxMerkleNode::from_byte_array([0x77; 32]),
+            time: Timestamp::from(2),
+            bits: CompactTarget::from_consensus(3),
+            nonce: 4,
+        }
+    }
+
     #[test]
     fn version_is_not_signalling_with_invalid_bit() {
         let arbitrary_version = Version::from_consensus(1_234_567_890);
@@ -395,17 +406,16 @@ mod tests {
         assert_eq!(version.to_consensus(), 1_234_567_890);
     }
 
+    #[test]
+    fn version_default() {
+        let version = Version::default();
+        assert_eq!(version.to_consensus(), Version::NO_SOFT_FORK_SIGNALLING.to_consensus());
+    }
+
     // Check that the size of the header consensus serialization matches the const SIZE value
     #[test]
     fn header_size() {
-        let header = Header {
-            version: Version::ONE,
-            prev_blockhash: BlockHash::from_byte_array([0x99; 32]),
-            merkle_root: TxMerkleNode::from_byte_array([0x77; 32]),
-            time: Timestamp::from(2),
-            bits: CompactTarget::from_consensus(3),
-            nonce: 4,
-        };
+        let header = dummy_header();
 
         // Calculate the size of the block header in bytes from the sum of the serialized lengths
         // it's fields: version, prev_blockhash, merkle_root, time, bits, nonce.
@@ -418,4 +428,108 @@ mod tests {
 
         assert_eq!(header_size, Header::SIZE);
     }
+
+    #[test]
+    #[cfg(feature = "alloc")]
+    fn block_new_unchecked() {
+        let header = dummy_header();
+        let transactions = vec![];
+        let block = Block::new_unchecked(header, transactions.clone());
+        assert_eq!(block.header, header);
+        assert_eq!(block.transactions, transactions);
+    }
+
+    #[test]
+    #[cfg(feature = "alloc")]
+    fn block_assume_checked() {
+        let header = dummy_header();
+        let transactions = vec![];
+        let block = Block::new_unchecked(header, transactions.clone());
+        let witness_root = Some(WitnessMerkleNode::from_byte_array([0x88; 32]));
+        let checked_block = block.assume_checked(witness_root);
+        assert_eq!(checked_block.header(), &header);
+        assert_eq!(checked_block.transactions(), &transactions);
+        assert_eq!(checked_block.cached_witness_root(), witness_root);
+    }
+
+    #[test]
+    #[cfg(feature = "alloc")]
+    fn block_into_parts() {
+        let header = dummy_header();
+        let transactions = vec![];
+        let block = Block::new_unchecked(header, transactions.clone());
+        let (block_header, block_transactions) = block.into_parts();
+        assert_eq!(block_header, header);
+        assert_eq!(block_transactions, transactions);
+    }
+
+    #[test]
+    #[cfg(feature = "alloc")]
+    fn block_cached_witness_root() {
+        let header = dummy_header();
+        let transactions = vec![];
+        let block = Block::new_unchecked(header, transactions);
+        let witness_root = Some(WitnessMerkleNode::from_byte_array([0x88; 32]));
+        let checked_block = block.assume_checked(witness_root);
+        assert_eq!(checked_block.cached_witness_root(), witness_root);
+    }
+
+    #[test]
+    #[cfg(feature = "alloc")]
+    fn block_block_hash() {
+        let header = dummy_header();
+        let transactions = vec![];
+        let block = Block::new_unchecked(header, transactions);
+        assert_eq!(block.block_hash(), header.block_hash());
+    }
+
+    #[test]
+    fn block_hash_from_header() {
+        let header = dummy_header();
+        let block_hash = header.block_hash();
+        assert_eq!(block_hash, BlockHash::from(header));
+    }
+
+    #[test]
+    fn block_hash_from_header_ref() {
+        let header = dummy_header();
+        let block_hash: BlockHash = BlockHash::from(&header);
+        assert_eq!(block_hash, header.block_hash());
+    }
+
+    #[test]
+    #[cfg(feature = "alloc")]
+    fn block_hash_from_block() {
+        let header = dummy_header();
+        let transactions = vec![];
+        let block = Block::new_unchecked(header, transactions);
+        let block_hash: BlockHash = BlockHash::from(block);
+        assert_eq!(block_hash, header.block_hash());
+    }
+
+    #[test]
+    #[cfg(feature = "alloc")]
+    fn block_hash_from_block_ref() {
+        let header = dummy_header();
+        let transactions = vec![];
+        let block = Block::new_unchecked(header, transactions);
+        let block_hash: BlockHash = BlockHash::from(&block);
+        assert_eq!(block_hash, header.block_hash());
+    }
+
+    #[test]
+    fn header_debug() {
+        let header = dummy_header();
+        let expected = format!(
+            "Header {{ block_hash: {:?}, version: {:?}, prev_blockhash: {:?}, merkle_root: {:?}, time: {:?}, bits: {:?}, nonce: {:?} }}",
+            header.block_hash(),
+            header.version,
+            header.prev_blockhash,
+            header.merkle_root,
+            header.time,
+            header.bits,
+            header.nonce
+        );
+        assert_eq!(format!("{:?}", header), expected);
+    }
 }