Comments and better panic prints for e2e tests

tests/e2e/instance_test.go

@@ -21,6 +21,8 @@ import (
 func TestCCVTestSuite(t *testing.T) {
 
 	// Pass in concrete app types that implement the interfaces defined in /testutil/e2e/interfaces.go
+	// IMPORTANT: the concrete app types passed in as type parameters here must match the
+	// concrete app types returned by the relevant app initers.
 	ccvSuite := e2e.NewCCVTestSuite[*appProvider.App, *appConsumer.App](
 		// Pass in ibctesting.AppIniters for provider and consumer.
 		icstestingutils.ProviderAppIniter, icstestingutils.ConsumerAppIniter, []string{})
@@ -32,6 +34,8 @@ func TestCCVTestSuite(t *testing.T) {
 // Executes a standard suite of tests, against a democracy consumer app.go implementation.
 func TestConsumerDemocracyCCVTestSuite(t *testing.T) {
 	// Pass in concrete app type that implement the interface defined in /testutil/e2e/interfaces.go
+	// IMPORTANT: the concrete app types passed in as type parameters here must match the
+	// concrete app types returned by the relevant app initers.
 	democSuite := e2e.NewCCVTestSuite[*appProvider.App, *appConsumerDemocracy.App](
 		// Pass in ibctesting.AppIniter for provider and democracy consumer.
 		// TestRewardsDistribution needs to be skipped since the democracy specific distribution test is in ConsumerDemocracyTestSuite,
@@ -47,6 +51,8 @@ func TestConsumerDemocracyCCVTestSuite(t *testing.T) {
 func TestConsumerDemocracyTestSuite(t *testing.T) {
 
 	// Pass in concrete app type that implement the interface defined in /testutil/e2e/interfaces.go
+	// IMPORTANT: the concrete app type passed in as a type parameter here must match the
+	// concrete app type returned by the relevant app initer.
 	democSuite := e2e.NewConsumerDemocracyTestSuite[*appConsumerDemocracy.App](
 		// Pass in ibctesting.AppIniter for democracy consumer.
 		icstestingutils.DemocracyConsumerAppIniter)

testutil/ibc_testing/generic_setup.go

@@ -1,6 +1,7 @@
 package ibc_testing
 
 import (
+	"fmt"
 	"testing"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -52,7 +53,12 @@ func AddProvider[T e2eutil.ProviderApp](coordinator *ibctesting.Coordinator, t *
 	provider := ibctesting.NewTestChain(t, coordinator, appIniter, provChainID)
 	coordinator.Chains[provChainID] = provider
 
-	return provider, provider.App.(T)
+	providerToReturn, ok := provider.App.(T)
+	if !ok {
+		panic(fmt.Sprintf("provider app type returned from app initer does not match app type passed in as type param: %T, %T",
+			provider.App, *new(T)))
+	}
+	return provider, providerToReturn
 }
 
 // AddDemocracyConsumer adds a new democ consumer chain to the coordinator and returns the test chain and app type
@@ -62,7 +68,12 @@ func AddDemocracyConsumer[T e2eutil.DemocConsumerApp](coordinator *ibctesting.Co
 	democConsumer := ibctesting.NewTestChain(t, coordinator, appIniter, democConsumerChainID)
 	coordinator.Chains[democConsumerChainID] = democConsumer
 
-	return democConsumer, democConsumer.App.(T)
+	democConsumerToReturn, ok := democConsumer.App.(T)
+	if !ok {
+		panic(fmt.Sprintf("democ consumer app type returned from app initer does not match app type passed in as type param: %T, %T",
+			democConsumer.App, *new(T)))
+	}
+	return democConsumer, democConsumerToReturn
 }
 
 // AddConsumer adds a new consumer chain with "testchain<index+2>" as chainID to the coordinator
@@ -125,8 +136,14 @@ func AddConsumer[Tp e2eutil.ProviderApp, Tc e2eutil.ConsumerApp](
 		appIniter, chainID, tmtypes.NewValidatorSet(valz), providerChain.Signers)
 	coordinator.Chains[chainID] = testChain
 
+	consumerToReturn, ok := testChain.App.(Tc)
+	if !ok {
+		panic(fmt.Sprintf("consumer app type returned from app initer does not match app type passed in as type param: %T, %T",
+			testChain.App, *new(Tc)))
+	}
+
 	return &ConsumerBundle{
 		Chain: testChain,
-		App:   testChain.App.(Tc),
+		App:   consumerToReturn,
 	}
 }