feat: validate duplicate provider names in NewRequestBridge

Author: ssncferreira

bridge.go

@@ -57,6 +57,19 @@ type RequestBridge struct {
 
 var _ http.Handler = &RequestBridge{}
 
+// validateProviders checks that no two providers share the same name.
+func validateProviders(providers []provider.Provider) error {
+	names := make(map[string]bool, len(providers))
+	for _, prov := range providers {
+		if names[prov.Name()] {
+			return fmt.Errorf("duplicate provider name: %q", prov.Name())
+		}
+		names[prov.Name()] = true
+	}
+	// TODO(ssncferreira): validate duplicate baseURLs as well
+	return nil
+}
+
 // NewRequestBridge creates a new *[RequestBridge] and registers the HTTP routes defined by the given providers.
 // Any routes which are requested but not registered will be reverse-proxied to the upstream service.
 //
@@ -67,6 +80,10 @@ var _ http.Handler = &RequestBridge{}
 // Circuit breaker configuration is obtained from each provider's CircuitBreakerConfig() method.
 // Providers returning nil will not have circuit breaker protection.
 func NewRequestBridge(ctx context.Context, providers []provider.Provider, rec recorder.Recorder, mcpProxy mcp.ServerProxier, logger slog.Logger, m *metrics.Metrics, tracer trace.Tracer) (*RequestBridge, error) {
+	if err := validateProviders(providers); err != nil {
+		return nil, err
+	}
+
 	mux := http.NewServeMux()
 
 	for _, prov := range providers {

bridge_test.go

@@ -13,6 +13,72 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestValidateProviders(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name      string
+		providers []provider.Provider
+		expectErr string
+	}{
+		{
+			name: "all_supported_providers",
+			providers: []provider.Provider{
+				NewOpenAIProvider(config.OpenAI{Name: "openai", BaseURL: "https://api.openai.com/v1/"}),
+				NewAnthropicProvider(config.Anthropic{Name: "anthropic", BaseURL: "https://api.anthropic.com/"}, nil),
+				NewCopilotProvider(config.Copilot{Name: "copilot", BaseURL: "https://api.individual.githubcopilot.com"}),
+				NewCopilotProvider(config.Copilot{Name: "copilot-business", BaseURL: "https://api.business.githubcopilot.com"}),
+				NewCopilotProvider(config.Copilot{Name: "copilot-enterprise", BaseURL: "https://api.enterprise.githubcopilot.com"}),
+			},
+		},
+		{
+			name: "default_names_and_base_urls",
+			providers: []provider.Provider{
+				NewOpenAIProvider(config.OpenAI{}),
+				NewAnthropicProvider(config.Anthropic{}, nil),
+				NewCopilotProvider(config.Copilot{}),
+			},
+		},
+		{
+			name: "multiple_copilot_instances",
+			providers: []provider.Provider{
+				NewCopilotProvider(config.Copilot{}),
+				NewCopilotProvider(config.Copilot{Name: "copilot-business", BaseURL: "https://api.business.githubcopilot.com"}),
+				NewCopilotProvider(config.Copilot{Name: "copilot-enterprise", BaseURL: "https://api.enterprise.githubcopilot.com"}),
+			},
+		},
+		{
+			name: "duplicate_name",
+			providers: []provider.Provider{
+				NewCopilotProvider(config.Copilot{Name: "copilot", BaseURL: "https://api.individual.githubcopilot.com"}),
+				NewCopilotProvider(config.Copilot{Name: "copilot", BaseURL: "https://api.business.githubcopilot.com"}),
+			},
+			expectErr: "duplicate provider name",
+		},
+		{
+			name: "duplicate_base_url_different_names",
+			providers: []provider.Provider{
+				NewCopilotProvider(config.Copilot{Name: "copilot", BaseURL: "https://api.individual.githubcopilot.com"}),
+				NewCopilotProvider(config.Copilot{Name: "copilot-business", BaseURL: "https://api.individual.githubcopilot.com"}),
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			err := validateProviders(tc.providers)
+			if tc.expectErr != "" {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), tc.expectErr)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
 func TestPassthroughRoutesForProviders(t *testing.T) {
 	t.Parallel()