fix(init): preserve protocol selection order from server (BLO-802)

cmd/substreams/init.go

@@ -208,12 +208,15 @@ func runSubstreamsInitE(cmd *cobra.Command, args []string) error {
 			Generators []*pbconvo.DiscoveryResponse_Generator
 		}
 
+		// Use a slice to maintain insertion order and a map for lookup
+		var protocolOrder []string
 		filteredProtocols := make(map[string]*BlockchainProtocolSelector)
 		for _, gen := range resp.Msg.Generators {
 			selector, groupExists := filteredProtocols[gen.Group]
 			if groupExists {
 				selector.Generators = append(selector.Generators, gen)
 			} else {
+				protocolOrder = append(protocolOrder, gen.Group)
 				filteredProtocols[gen.Group] = &BlockchainProtocolSelector{
 					Id:         gen.Group,
 					Title:      gen.Group,
@@ -223,7 +226,8 @@ func runSubstreamsInitE(cmd *cobra.Command, args []string) error {
 		}
 
 		protocolOptions := make([]huh.Option[*BlockchainProtocolSelector], 0, len(filteredProtocols))
-		for _, value := range filteredProtocols {
+		for _, group := range protocolOrder {
+			value := filteredProtocols[group]
 			protocolOptions = append(protocolOptions, huh.Option[*BlockchainProtocolSelector]{
 				Key:   value.Title,
 				Value: value,

cmd/substreams/init_test.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	pbconvo "github.com/streamingfast/substreams/pb/sf/codegen/conversation/v1"
+)
+
+func TestProtocolOrderPreservation(t *testing.T) {
+	// Simulate generators received from server in specific order
+	generators := []*pbconvo.DiscoveryResponse_Generator{
+		{Id: "evm-events-calls", Group: "EVM", Title: "EVM Events/Calls"},
+		{Id: "evm-hello-world", Group: "EVM", Title: "EVM Hello World"},
+		{Id: "sol-anchor", Group: "Solana", Title: "Solana Anchor"},
+		{Id: "sol-hello-world", Group: "Solana", Title: "Solana Hello World"},
+		{Id: "starknet-events", Group: "Starknet", Title: "Starknet Events"},
+	}
+
+	// Reproduce the grouping logic
+	type BlockchainProtocolSelector struct {
+		Id         string
+		Title      string
+		Generators []*pbconvo.DiscoveryResponse_Generator
+	}
+
+	var protocolOrder []string
+	filteredProtocols := make(map[string]*BlockchainProtocolSelector)
+	for _, gen := range generators {
+		selector, groupExists := filteredProtocols[gen.Group]
+		if groupExists {
+			selector.Generators = append(selector.Generators, gen)
+		} else {
+			protocolOrder = append(protocolOrder, gen.Group)
+			filteredProtocols[gen.Group] = &BlockchainProtocolSelector{
+				Id:         gen.Group,
+				Title:      gen.Group,
+				Generators: []*pbconvo.DiscoveryResponse_Generator{gen},
+			}
+		}
+	}
+
+	// Verify order is preserved
+	require.Len(t, protocolOrder, 3)
+	assert.Equal(t, "EVM", protocolOrder[0])
+	assert.Equal(t, "Solana", protocolOrder[1])
+	assert.Equal(t, "Starknet", protocolOrder[2])
+
+	// Verify generators within each group maintain order
+	evmGens := filteredProtocols["EVM"].Generators
+	require.Len(t, evmGens, 2)
+	assert.Equal(t, "evm-events-calls", evmGens[0].Id)
+	assert.Equal(t, "evm-hello-world", evmGens[1].Id)
+
+	solanaGens := filteredProtocols["Solana"].Generators
+	require.Len(t, solanaGens, 2)
+	assert.Equal(t, "sol-anchor", solanaGens[0].Id)
+	assert.Equal(t, "sol-hello-world", solanaGens[1].Id)
+}