Rpc small fixes (#296)

* Fix receipt's log transaction_hash

* Block's total_difficulty default to 0

* Update ts-test

client/rpc-core/src/types/block.rs

@@ -79,7 +79,7 @@ pub struct Block {
 	/// Difficulty
 	pub difficulty: U256,
 	/// Total difficulty
-	pub total_difficulty: Option<U256>,
+	pub total_difficulty: U256,
 	/// Seal fields
 	pub seal_fields: Vec<Bytes>,
 	/// Uncles' hashes

client/rpc/src/eth.rs

@@ -111,7 +111,7 @@ fn rich_block_build(
 			logs_bloom: Some(block.header.logs_bloom),
 			timestamp: U256::from(block.header.timestamp / 1000),
 			difficulty: block.header.difficulty,
-			total_difficulty: None,
+			total_difficulty: U256::zero(),
 			seal_fields: vec![
 				Bytes(block.header.mix_hash.as_bytes().to_vec()),
 				Bytes(block.header.nonce.as_bytes().to_vec())
@@ -1055,7 +1055,7 @@ impl<B, C, P, CT, BE, H: ExHashT> EthApiT for EthApi<B, C, P, CT, BE, H> where
 								data: Bytes(log.data.clone()),
 								block_hash: Some(block_hash),
 								block_number: Some(block.header.number),
-								transaction_hash: Some(hash),
+								transaction_hash: Some(status.transaction_hash),
 								transaction_index: Some(status.transaction_index.into()),
 								log_index: Some(U256::from(
 									(pre_receipts_log_index.unwrap_or(0)) + i as u32

ts-tests/tests/test-block.ts

@@ -30,7 +30,7 @@ describeWithFrontier("Frontier RPC (Block)", `simple-specs.json`, (context) => {
 			receiptsRoot: "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
 			size: 505,
 			timestamp: 0,
-			totalDifficulty: null,
+			totalDifficulty: "0",
 		});
 
 		expect((block as any).sealFields).to.eql([
@@ -85,7 +85,7 @@ describeWithFrontier("Frontier RPC (Block)", `simple-specs.json`, (context) => {
 			receiptsRoot: "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
 			size: 505,
 			timestamp: 0,
-			totalDifficulty: null,
+			totalDifficulty: "0",
 		});
 
 		expect((block as any).sealFields).to.eql([
@@ -116,7 +116,7 @@ describeWithFrontier("Frontier RPC (Block)", `simple-specs.json`, (context) => {
 			receiptsRoot: "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
 			size: 507,
 			timestamp: 6,
-			totalDifficulty: null,
+			totalDifficulty: "0",
 			//transactions: [],
 			transactionsRoot: "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
 			//uncles: []