core: add GenerateChain, GenesisBlockForTesting

1 files changed, 78 insertions, 0 deletions

diff --git a/core/chain_makers_test.go b/core/chain_makers_test.go
new file mode 100644
index 000000000..d5125e1c3
--- /dev/null
+++ b/core/chain_makers_test.go
@@ -0,0 +1,78 @@
+package core
+
+import (
+	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+func ExampleGenerateChain() {
+	var (
+		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+		key2, _ = crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
+		key3, _ = crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
+		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
+		addr2   = crypto.PubkeyToAddress(key2.PublicKey)
+		addr3   = crypto.PubkeyToAddress(key3.PublicKey)
+		db, _   = ethdb.NewMemDatabase()
+	)
+
+	// Ensure that key1 has some funds in the genesis block.
+	genesis := GenesisBlockForTesting(db, addr1, big.NewInt(1000000))
+
+	// This call generates a chain of 5 blocks. The function runs for
+	// each block and adds different features to gen based on the
+	// block index.
+	chain := GenerateChain(genesis, db, 5, func(i int, gen *BlockGen) {
+		switch i {
+		case 0:
+			// In block 1, addr1 sends addr2 some ether.
+			tx, _ := types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(key1)
+			gen.AddTx(tx)
+		case 1:
+			// In block 2, addr1 sends some more ether to addr2.
+			// addr2 passes it on to addr3.
+			tx1, _ := types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(key1)
+			tx2, _ := types.NewTransaction(gen.TxNonce(addr2), addr3, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(key2)
+			gen.AddTx(tx1)
+			gen.AddTx(tx2)
+		case 2:
+			// Block 3 is empty but was mined by addr3.
+			gen.SetCoinbase(addr3)
+			gen.SetExtra([]byte("yeehaw"))
+		case 3:
+			// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
+			b2 := gen.PrevBlock(1).Header()
+			b2.Extra = []byte("foo")
+			gen.AddUncle(b2)
+			b3 := gen.PrevBlock(2).Header()
+			b3.Extra = []byte("foo")
+			gen.AddUncle(b3)
+		}
+	})
+
+	// Import the chain. This runs all block validation rules.
+	evmux := &event.TypeMux{}
+	chainman, _ := NewChainManager(genesis, db, db, FakePow{}, evmux)
+	chainman.SetProcessor(NewBlockProcessor(db, db, FakePow{}, chainman, evmux))
+	if i, err := chainman.InsertChain(chain); err != nil {
+		fmt.Printf("insert error (block %d): %v\n", i, err)
+		return
+	}
+
+	state := chainman.State()
+	fmt.Printf("last block: #%d\n", chainman.CurrentBlock().Number())
+	fmt.Println("balance of addr1:", state.GetBalance(addr1))
+	fmt.Println("balance of addr2:", state.GetBalance(addr2))
+	fmt.Println("balance of addr3:", state.GetBalance(addr3))
+	// Output:
+	// last block: #5
+	// balance of addr1: 989000
+	// balance of addr2: 10000
+	// balance of addr3: 5906250000000001000
+}