Fix merge redundancies and test both external chain configs.

Both branches had made a TestChainConfig_GetChainID.

core/config_test.go

@@ -292,24 +292,39 @@ func TestChainConfig_GetFeature4_WorkForHighNumbers(t *testing.T) {
 }
 
 func TestChainConfig_GetChainID(t *testing.T) {
+	// Test default hardcoded configs.
 	if DefaultConfig.GetChainID().Cmp(DefaultChainConfigChainID) != 0 {
 		t.Error("got: %v, want: %v", DefaultConfig.GetChainID(), DefaultTestnetChainConfigChainID)
 	}
 	if TestConfig.GetChainID().Cmp(DefaultTestnetChainConfigChainID) != 0 {
 		t.Error("got: %v, want: %v", TestConfig.GetChainID(), DefaultTestnetChainConfigChainID)
 	}
 
-	// Test parsing default external config.
-	p, e := filepath.Abs("../cmd/geth/config/mainnet.json")
-	if e != nil {
-		t.Errorf("filepath err: %v", e)
+	// If no chainID (config is empty) returns 0.
+	c := &ChainConfig{}
+	cid := c.GetChainID()
+	// check is zero
+	if cid.Cmp(new(big.Int)) != 0 {
+		t.Errorf("got: %v, want: %v", cid, new(big.Int))
 	}
-	extConfig, err := ReadExternalChainConfig(p)
-	if err != nil {
-		t.Errorf("could not find file: %v", err)
+
+	// Test parsing default external mainnet config.
+	cases := map[string]*big.Int{
+		"../cmd/geth/config/mainnet.json": DefaultChainConfigChainID,
+		"../cmd/geth/config/testnet.json": DefaultTestnetChainConfigChainID,
 	}
-	if extConfig.ChainConfig.GetChainID().Cmp(big.NewInt(61)) != 0 {
-		t.Error("found 0 chainid for eip155")
+	for extConfigPath, wantInt := range cases {
+		p, e := filepath.Abs(extConfigPath)
+		if e != nil {
+			t.Errorf("filepath err: %v", e)
+		}
+		extConfig, err := ReadExternalChainConfig(p)
+		if err != nil {
+			t.Errorf("could not find file: %v", err)
+		}
+		if extConfig.ChainConfig.GetChainID().Cmp(wantInt) != 0 {
+			t.Error("got: %v, want: %v", extConfig.ChainConfig.GetChainID(), wantInt)
+		}
 	}
 }
 
@@ -491,28 +506,6 @@ func TestChainConfig_GetSigner(t *testing.T) {
 
 }
 
-func TestChainConfig_GetChainID(t *testing.T) {
-	d := DefaultConfig
-	cid := d.GetChainID()
-	// check is not zero
-	if cid.Cmp(new(big.Int)) == 0 {
-		t.Errorf("got: %v, want: %v", cid, DefaultChainConfigChainID)
-	}
-	// check is expected default 61
-	if cid.Cmp(DefaultChainConfigChainID) != 0 {
-		t.Errorf("got: %v, want: %v", cid, DefaultChainConfigChainID)
-	}
-
-	// no chain id feature configured, should return zero-value (0)
-	d = &ChainConfig{}
-	cid = d.GetChainID()
-	// check is zero
-	if cid.Cmp(new(big.Int)) != 0 {
-		t.Errorf("got: %v, want: %v", cid, new(big.Int))
-	}
-
-}
-
 func makeOKSufficientChainConfig(dump *GenesisDump, config *ChainConfig) *SufficientChainConfig {
 	// Setup.
 	whole := &SufficientChainConfig{}