Add tests for network registration.

While here, fix a bug found through testing.  Register will now return
ErrDuplicateNet if the caller attempts to register any of the standard
network parameters provided by this package.

ok @davecgh

params.go

@@ -275,7 +275,12 @@ var (
 )
 
 var (
-	registeredNets = map[btcwire.BitcoinNet]struct{}{}
+	registeredNets = map[btcwire.BitcoinNet]struct{}{
+		MainNetParams.Net:       struct{}{},
+		TestNet3Params.Net:      struct{}{},
+		RegressionNetParams.Net: struct{}{},
+		SimNetParams.Net:        struct{}{},
+	}
 
 	pubKeyHashAddrIDs = map[byte]struct{}{
 		MainNetParams.PubKeyHashAddrID:  struct{}{},
@@ -291,7 +296,9 @@ var (
 )
 
 // Register registers the network parameters for a Bitcoin network.  This may
-// error with ErrDuplicateNet if the network is already registered.
+// error with ErrDuplicateNet if the network is already registered (either
+// due to a previous Register call, or the network being one of the default
+// networks).
 //
 // Network parameters should be registered into this package by a main package
 // as early as possible.  Then, library packages may lookup networks or network

register_test.go

@@ -0,0 +1,281 @@
+package btcnet_test
+
+import (
+	. "github.com/conformal/btcnet"
+	"testing"
+)
+
+// Define some of the required parameters for a user-registered
+// network.  This is necessary to test the registration of and
+// lookup of encoding magics from the network.
+var mockNetParams = Params{
+	Name:             "mocknet",
+	Net:              1<<32 - 1,
+	PubKeyHashAddrID: 0x9f,
+	ScriptHashAddrID: 0xf9,
+}
+
+func TestRegister(t *testing.T) {
+	type registerTest struct {
+		name   string
+		params *Params
+		err    error
+	}
+	type magicTest struct {
+		magic byte
+		valid bool
+	}
+
+	tests := []struct {
+		name        string
+		register    []registerTest
+		p2pkhMagics []magicTest
+		p2shMagics  []magicTest
+	}{
+		{
+			name: "default networks",
+			register: []registerTest{
+				{
+					name:   "duplicate mainnet",
+					params: &MainNetParams,
+					err:    ErrDuplicateNet,
+				},
+				{
+					name:   "duplicate regtest",
+					params: &RegressionNetParams,
+					err:    ErrDuplicateNet,
+				},
+				{
+					name:   "duplicate testnet3",
+					params: &TestNet3Params,
+					err:    ErrDuplicateNet,
+				},
+				{
+					name:   "duplicate simnet",
+					params: &SimNetParams,
+					err:    ErrDuplicateNet,
+				},
+			},
+			p2pkhMagics: []magicTest{
+				{
+					magic: MainNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: TestNet3Params.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: RegressionNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: SimNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: mockNetParams.PubKeyHashAddrID,
+					valid: false,
+				},
+				{
+					magic: 0xFF,
+					valid: false,
+				},
+			},
+			p2shMagics: []magicTest{
+				{
+					magic: MainNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: TestNet3Params.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: RegressionNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: SimNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: mockNetParams.ScriptHashAddrID,
+					valid: false,
+				},
+				{
+					magic: 0xFF,
+					valid: false,
+				},
+			},
+		},
+		{
+			name: "register mocknet",
+			register: []registerTest{
+				{
+					name:   "mocknet",
+					params: &mockNetParams,
+					err:    nil,
+				},
+			},
+			p2pkhMagics: []magicTest{
+				{
+					magic: MainNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: TestNet3Params.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: RegressionNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: SimNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: mockNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: 0xFF,
+					valid: false,
+				},
+			},
+			p2shMagics: []magicTest{
+				{
+					magic: MainNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: TestNet3Params.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: RegressionNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: SimNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: mockNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: 0xFF,
+					valid: false,
+				},
+			},
+		},
+		{
+			name: "more duplicates",
+			register: []registerTest{
+				{
+					name:   "duplicate mainnet",
+					params: &MainNetParams,
+					err:    ErrDuplicateNet,
+				},
+				{
+					name:   "duplicate regtest",
+					params: &RegressionNetParams,
+					err:    ErrDuplicateNet,
+				},
+				{
+					name:   "duplicate testnet3",
+					params: &TestNet3Params,
+					err:    ErrDuplicateNet,
+				},
+				{
+					name:   "duplicate simnet",
+					params: &SimNetParams,
+					err:    ErrDuplicateNet,
+				},
+				{
+					name:   "duplicate mocknet",
+					params: &mockNetParams,
+					err:    ErrDuplicateNet,
+				},
+			},
+			p2pkhMagics: []magicTest{
+				{
+					magic: MainNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: TestNet3Params.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: RegressionNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: SimNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: mockNetParams.PubKeyHashAddrID,
+					valid: true,
+				},
+				{
+					magic: 0xFF,
+					valid: false,
+				},
+			},
+			p2shMagics: []magicTest{
+				{
+					magic: MainNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: TestNet3Params.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: RegressionNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: SimNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: mockNetParams.ScriptHashAddrID,
+					valid: true,
+				},
+				{
+					magic: 0xFF,
+					valid: false,
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		for _, regTest := range test.register {
+			err := Register(regTest.params)
+			if err != regTest.err {
+				t.Errorf("%s:%s: Registered network with unexpected error: got %v expected %v",
+					test.name, regTest.name, err, regTest.err)
+			}
+		}
+		for i, magTest := range test.p2pkhMagics {
+			valid := IsPubKeyHashAddrID(magTest.magic)
+			if valid != magTest.valid {
+				t.Errorf("%s: P2PKH magic %d valid mismatch: got %v expected %v",
+					test.name, i, valid, magTest.valid)
+			}
+		}
+		for i, magTest := range test.p2shMagics {
+			valid := IsScriptHashAddrID(magTest.magic)
+			if valid != magTest.valid {
+				t.Errorf("%s: P2SH magic %d valid mismatch: got %v expected %v",
+					test.name, i, valid, magTest.valid)
+			}
+		}
+	}
+}