itest: make commit type enum

To prepare for adding more commit types to test for basic channel
funding, we make the commit type an enum that gets its own set of
subtests.

lntest/itest/lnd_test.go

@@ -953,6 +953,43 @@ func testOnchainFundRecovery(net *lntest.NetworkHarness, t *harnessTest) {
 	restoreCheckBalance(6*btcutil.SatoshiPerBitcoin, 6, 20, nil)
 }
 
+// commitType is a simple enum used to run though the basic funding flow with
+// different commitment formats.
+type commitType byte
+
+const (
+	// commitTypeLegacy is the old school commitment type.
+	commitTypeLegacy = iota
+
+	// commiTypeTweakless is the commitment type where the remote key is
+	// static (non-tweaked).
+	commitTypeTweakless
+)
+
+// String returns that name of the commitment type.
+func (c commitType) String() string {
+	switch c {
+	case commitTypeLegacy:
+		return "legacy"
+	case commitTypeTweakless:
+		return "tweakless"
+	default:
+		return "invalid"
+	}
+}
+
+// Args returns the command line flag to supply to enable this commitment type.
+func (c commitType) Args() []string {
+	switch c {
+	case commitTypeLegacy:
+		return []string{"--legacyprotocol.committweak"}
+	case commitTypeTweakless:
+		return []string{}
+	}
+
+	return nil
+}
+
 // basicChannelFundingTest is a sub-test of the main testBasicChannelFunding
 // test. Given two nodes: Alice and Bob, it'll assert proper channel creation,
 // then return a function closure that should be called to assert proper
@@ -1049,19 +1086,23 @@ func testBasicChannelFunding(net *lntest.NetworkHarness, t *harnessTest) {
 
 	ctxb := context.Background()
 
+	// Run through the test with combinations of all the different
+	// commitment types.
+	allTypes := []commitType{
+		commitTypeLegacy,
+		commitTypeTweakless,
+	}
+
 test:
 	// We'll test all possible combinations of the feature bit presence
 	// that both nodes can signal for this new channel type. We'll make a
 	// new Carol+Dave for each test instance as well.
-	for _, carolTweakless := range []bool{true, false} {
-		for _, daveTweakless := range []bool{true, false} {
+	for _, carolCommitType := range allTypes {
+		for _, daveCommitType := range allTypes {
 			// Based on the current tweak variable for Carol, we'll
 			// preferentially signal the legacy commitment format.
 			// We do the same for Dave shortly below.
-			var carolArgs []string
-			if !carolTweakless {
-				carolArgs = []string{"--legacyprotocol.committweak"}
-			}
+			carolArgs := carolCommitType.Args()
 			carol, err := net.NewNode("Carol", carolArgs)
 			if err != nil {
 				t.Fatalf("unable to create new node: %v", err)
@@ -1075,10 +1116,7 @@ test:
 				t.Fatalf("unable to send coins to carol: %v", err)
 			}
 
-			var daveArgs []string
-			if !daveTweakless {
-				daveArgs = []string{"--legacyprotocol.committweak"}
-			}
+			daveArgs := daveCommitType.Args()
 			dave, err := net.NewNode("Dave", daveArgs)
 			if err != nil {
 				t.Fatalf("unable to create new node: %v", err)
@@ -1093,8 +1131,8 @@ test:
 				t.Fatalf("unable to connect peers: %v", err)
 			}
 
-			testName := fmt.Sprintf("carol_tweak=%v,dave_tweak=%v",
-				carolTweakless, daveTweakless)
+			testName := fmt.Sprintf("carol_commit=%v,dave_commit=%v",
+				carolCommitType, daveCommitType)
 
 			ht := t
 			success := t.t.Run(testName, func(t *testing.T) {
@@ -1105,6 +1143,10 @@ test:
 					t.Fatalf("failed funding flow: %v", err)
 				}
 
+				carolTweakless := carolCommitType == commitTypeTweakless
+
+				daveTweakless := daveCommitType == commitTypeTweakless
+
 				tweaklessSignalled := carolTweakless && daveTweakless
 				tweaklessChans := (carolChannel.StaticRemoteKey &&
 					daveChannel.StaticRemoteKey)