accounts/abi/bind/backends: return hash of new blocks (ethereum#25163)

Co-authored-by: Jens <jmw.1906@gmx.de>

accounts/abi/bind/backends/simulated.go

@@ -109,7 +109,7 @@ func (b *SimulatedBackend) Close() error {
 
 // Commit imports all the pending transactions as a single block and starts a
 // fresh new state.
-func (b *SimulatedBackend) Commit() {
+func (b *SimulatedBackend) Commit() common.Hash {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 
@@ -131,10 +131,14 @@ func (b *SimulatedBackend) Commit() {
 	if _, err := b.blockchain.InsertChain([]*types.Block{blocks[0]}); err != nil {
 		panic(err) // This cannot happen unless the simulator is wrong, fail in that case
 	}
+	blockHash := b.pendingBlock.Hash()
+
 	// Using the last inserted block here makes it possible to build on a side
 	// chain after a fork.
 	b.stuckTransactions = remainingTx
 	b.rollback(blocks[0])
+
+	return blockHash
 }
 
 // Rollback aborts all pending transactions, reverting to the last committed state.

accounts/abi/bind/backends/simulated_test.go

@@ -1354,15 +1354,15 @@ func TestLowGasTxNotBeingMined(t *testing.T) {
 	defer sim.Close()
 
 	var testCases = []struct {
-		name     string
-		txType	 byte
+		name   string
+		txType byte
 	}{
 		{
-			name: "LegacyTx",
+			name:   "LegacyTx",
 			txType: types.LegacyTxType,
 		},
 		{
-			name: "dynamicTx",
+			name:   "dynamicTx",
 			txType: types.DynamicFeeTxType,
 		},
 	}
@@ -1413,7 +1413,7 @@ func TestLowGasTxNotBeingMined(t *testing.T) {
 			// expect nonce be the same because low gas fee tx will not be mined
 			nonce, err := sim.PendingNonceAt(bgCtx, testAddr)
 			require.NoError(t, err)
-			assert.Equal(t,  uint64(i), nonce)
+			assert.Equal(t, uint64(i), nonce)
 
 			// send tx with higher gas fee
 			sufficientGasFeeTx := types.NewTx(&types.LegacyTx{
@@ -1439,7 +1439,7 @@ func TestLowGasTxNotBeingMined(t *testing.T) {
 			// expect nonce has increased
 			nonce, err = sim.PendingNonceAt(bgCtx, testAddr)
 			require.NoError(t, err)
-			assert.Equal(t, uint64(i) + 1, nonce)
+			assert.Equal(t, uint64(i)+1, nonce)
 		})
 	}
 }
@@ -1453,15 +1453,15 @@ func TestLowGasTxNotBeingMined(t *testing.T) {
 // 4. Check tx get mined
 func TestLowGasTxGetMinedOnceGasFeeDropped(t *testing.T) {
 	var testCases = []struct {
-		name     string
-		txType	 byte
+		name   string
+		txType byte
 	}{
 		{
-			name: "LegacyTx",
+			name:   "LegacyTx",
 			txType: types.LegacyTxType,
 		},
 		{
-			name: "dynamicTx",
+			name:   "dynamicTx",
 			txType: types.DynamicFeeTxType,
 		},
 	}
@@ -1527,7 +1527,7 @@ func TestLowGasTxGetMinedOnceGasFeeDropped(t *testing.T) {
 			// nonce has increased
 			pendingNonce, err = sim.PendingNonceAt(bgCtx, testAddr)
 			require.NoError(t, err)
-			assert.Equal(t, uint64(i) + 1, pendingNonce)
+			assert.Equal(t, uint64(i)+1, pendingNonce)
 
 			// the transaction should have been mined
 			_, isPending, err := sim.TransactionByHash(bgCtx, signedTx.Hash())
@@ -1536,3 +1536,41 @@ func TestLowGasTxGetMinedOnceGasFeeDropped(t *testing.T) {
 		})
 	}
 }
+func TestCommitReturnValue(t *testing.T) {
+	testAddr := crypto.PubkeyToAddress(testKey.PublicKey)
+	sim := simTestBackend(testAddr)
+	defer sim.Close()
+
+	startBlockHeight := sim.blockchain.CurrentBlock().NumberU64()
+
+	// Test if Commit returns the correct block hash
+	h1 := sim.Commit()
+	if h1 != sim.blockchain.CurrentBlock().Hash() {
+		t.Error("Commit did not return the hash of the last block.")
+	}
+
+	// Create a block in the original chain (containing a transaction to force different block hashes)
+	head, _ := sim.HeaderByNumber(context.Background(), nil) // Should be child's, good enough
+	gasPrice := new(big.Int).Add(head.BaseFee, big.NewInt(1))
+	_tx := types.NewTransaction(0, testAddr, big.NewInt(1000), params.TxGas, gasPrice, nil)
+	tx, _ := types.SignTx(_tx, types.HomesteadSigner{}, testKey)
+	sim.SendTransaction(context.Background(), tx)
+	h2 := sim.Commit()
+
+	// Create another block in the original chain
+	sim.Commit()
+
+	// Fork at the first bock
+	if err := sim.Fork(context.Background(), h1); err != nil {
+		t.Errorf("forking: %v", err)
+	}
+
+	// Test if Commit returns the correct block hash after the reorg
+	h2fork := sim.Commit()
+	if h2 == h2fork {
+		t.Error("The block in the fork and the original block are the same block!")
+	}
+	if sim.blockchain.GetHeader(h2fork, startBlockHeight+2) == nil {
+		t.Error("Could not retrieve the just created block (side-chain)")
+	}
+}