[FAB-3091] TX ID missing from TX in genesis block

This changeset:
1. Modifies the `Factory`'s `Block` method so that a TX ID is set.
2. Adds a test for the issue in question. The test fails w/o this
changeset, and passes otherwise.

It also:
1. Add comments to the exported identifiers of the genesis package.
2. Renames all instances of `chainID` to `channelID` (we have to start
this transition eventually).
3. Modifies the tests so that they use the `assert` package.

Change-Id: I13db93326cbf43544812c1de4a515940163760e8
Signed-off-by: Kostas Christidis <kostas@christidis.io>

common/configtx/tool/provisional/provisional.go

@@ -59,7 +59,7 @@ const (
 
 	// TestChainID is the default value of ChainID. It is used by all testing
 	// networks. It it necessary to set and export this variable so that test
-	// clients can connect without being rejected for targetting a chain which
+	// clients can connect without being rejected for targeting a chain which
 	// does not exist.
 	TestChainID = "testchainid"
 

common/genesis/genesis.go

@@ -31,20 +31,24 @@ const (
 	epoch        = 0
 )
 
+// Factory facilitates the creation of genesis blocks.
 type Factory interface {
-	Block(chainID string) (*cb.Block, error)
+	// Block returns a genesis block for a given channel ID.
+	Block(channelID string) (*cb.Block, error)
 }
 
 type factory struct {
 	template configtx.Template
 }
 
+// NewFactoryImpl creates a new Factory.
 func NewFactoryImpl(template configtx.Template) Factory {
 	return &factory{template: template}
 }
 
-func (f *factory) Block(chainID string) (*cb.Block, error) {
-	configEnv, err := f.template.Envelope(chainID)
+// Block constructs and returns a genesis block for a given channel ID.
+func (f *factory) Block(channelID string) (*cb.Block, error) {
+	configEnv, err := f.template.Envelope(channelID)
 	if err != nil {
 		return nil, err
 	}
@@ -55,8 +59,9 @@ func (f *factory) Block(chainID string) (*cb.Block, error) {
 		return nil, err
 	}
 
-	payloadChannelHeader := utils.MakeChannelHeader(cb.HeaderType_CONFIG, msgVersion, chainID, epoch)
+	payloadChannelHeader := utils.MakeChannelHeader(cb.HeaderType_CONFIG, msgVersion, channelID, epoch)
 	payloadSignatureHeader := utils.MakeSignatureHeader(nil, utils.CreateNonceOrPanic())
+	utils.SetTxID(payloadChannelHeader, payloadSignatureHeader)
 	payloadHeader := utils.MakePayloadHeader(payloadChannelHeader, payloadSignatureHeader)
 	payload := &cb.Payload{Header: payloadHeader, Data: utils.MarshalOrPanic(&cb.ConfigEnvelope{Config: &cb.Config{ChannelGroup: configUpdate.WriteSet}})}
 	envelope := &cb.Envelope{Payload: utils.MarshalOrPanic(payload), Signature: nil}

common/genesis/genesis_test.go

@@ -20,12 +20,21 @@ import (
 	"testing"
 
 	"github.com/hyperledger/fabric/common/configtx"
+	"github.com/hyperledger/fabric/protos/utils"
+	"github.com/stretchr/testify/assert"
 )
 
-func TestSanity(t *testing.T) {
+func TestBasicSanity(t *testing.T) {
 	impl := NewFactoryImpl(configtx.NewSimpleTemplate())
-	_, err := impl.Block("TestChainID")
-	if err != nil {
-		t.Fatalf("Basic sanity fails")
-	}
+	_, err := impl.Block("testchainid")
+	assert.NoError(t, err, "Basic sanity fails")
+}
+
+func TestForTransactionID(t *testing.T) {
+	impl := NewFactoryImpl(configtx.NewSimpleTemplate())
+	block, _ := impl.Block("testchainid")
+	configEnv, _ := utils.ExtractEnvelope(block, 0)
+	configEnvPayload, _ := utils.ExtractPayload(configEnv)
+	configEnvPayloadChannelHeader, _ := utils.UnmarshalChannelHeader(configEnvPayload.GetHeader().ChannelHeader)
+	assert.NotEmpty(t, configEnvPayloadChannelHeader.TxId, "tx_id of configuration transaction should not be empty")
 }