test(bridge): cover the read-only REST surface + rpcErrToJSONRPC

tokens/exchanges/limits/profileGET (the /v1/bridge/{tokens,exchanges,
limits,profile} handlers the SDK's config bootstrap depends on),
SetProfile, stripPathPrefix (the legacy Express-proxy Director), and
rpcErrToJSONRPC were all untested.

Worth calling out: stripPathPrefix's empty-path case (a request to
exactly the /v1/bridge prefix with nothing after it) must rewrite to
"/", not "" -- an empty URL.Path on an outbound proxied request is
invalid and would break against most backends. Also covers
rpcErrToJSONRPC's fallback contract: a *bchain.RPCError with Code==0
(a transport failure that never got a real JSON-RPC code) must still
map to -32603, not propagate 0, which isn't a defined JSON-RPC error
code.

New cmd/bridge/api_test.go, 13 tests.

cmd/bridge/api_test.go

@@ -0,0 +1,221 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/hanzoai/zip"
+	middleware "github.com/hanzoai/zip/middleware"
+	"github.com/luxfi/bridge"
+	"github.com/luxfi/bridge/internal/bchain"
+)
+
+// apiRig is a minimal API+App pair for exercising the read-only REST
+// surface (tokens/exchanges/limits/profile) with controlled fixtures,
+// separate from metricsRig's zero-value config.
+type apiRig struct {
+	app *zip.App
+	api *API
+}
+
+func newAPIRig(t *testing.T, cfg Config) *apiRig {
+	t.Helper()
+	store := NewInMemoryStore()
+	engine := &QuoteEngine{Feed: NewStaticPriceFeed(defaultPrices())}
+	api := NewAPI(cfg, "", nil, nil, nil, store, engine)
+	app := zip.New(zip.Config{AppName: "lux-bridge-test-api", DisableStartupMessage: true})
+	app.Use(middleware.Recover(), middleware.RequestID())
+	api.Register(app)
+	return &apiRig{app: app, api: api}
+}
+
+// =============================================================================
+// GET /v1/bridge/tokens
+// =============================================================================
+
+func TestTokens_ReturnsAllWhenNoNetworkFilter(t *testing.T) {
+	rig := newAPIRig(t, Config{Tokens: []Token{
+		{Asset: "ETH", Network: "ETHEREUM_MAINNET"},
+		{Asset: "SOL", Network: "SOLANA_MAINNET"},
+	}})
+	_, body := fireRequest(t, rig.app, "GET", "/v1/bridge/tokens", nil)
+	var got []Token
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatalf("decode: %v (body=%s)", err, body)
+	}
+	if len(got) != 2 {
+		t.Fatalf("len = %d, want 2 (unfiltered)", len(got))
+	}
+}
+
+func TestTokens_FiltersByNetworkQueryParam(t *testing.T) {
+	rig := newAPIRig(t, Config{Tokens: []Token{
+		{Asset: "ETH", Network: "ETHEREUM_MAINNET"},
+		{Asset: "USDC", Network: "ETHEREUM_MAINNET"},
+		{Asset: "SOL", Network: "SOLANA_MAINNET"},
+	}})
+	_, body := fireRequest(t, rig.app, "GET", "/v1/bridge/tokens?network=ETHEREUM_MAINNET", nil)
+	var got []Token
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatalf("decode: %v (body=%s)", err, body)
+	}
+	if len(got) != 2 {
+		t.Fatalf("len = %d, want 2 (ETHEREUM_MAINNET only)", len(got))
+	}
+	for _, tok := range got {
+		if tok.Network != "" {
+			t.Errorf("Network should be json:\"-\" (server-side only), got %q in response", tok.Network)
+		}
+	}
+}
+
+func TestTokens_UnknownNetworkFilterReturnsEmptyNotAll(t *testing.T) {
+	rig := newAPIRig(t, Config{Tokens: []Token{{Asset: "ETH", Network: "ETHEREUM_MAINNET"}}})
+	_, body := fireRequest(t, rig.app, "GET", "/v1/bridge/tokens?network=NOPE", nil)
+	var got []Token
+	_ = json.Unmarshal(body, &got)
+	if len(got) != 0 {
+		t.Fatalf("len = %d, want 0 for an unknown network filter", len(got))
+	}
+}
+
+// =============================================================================
+// GET /v1/bridge/exchanges, /v1/bridge/limits, /v1/bridge/profile
+// =============================================================================
+
+func TestExchanges_ReturnsConfiguredList(t *testing.T) {
+	rig := newAPIRig(t, Config{Exchanges: []Exchange{{InternalName: "coinbase", DisplayName: "Coinbase"}}})
+	status, body := fireRequest(t, rig.app, "GET", "/v1/bridge/exchanges", nil)
+	if status != http.StatusOK {
+		t.Fatalf("status = %d, want 200", status)
+	}
+	var got []Exchange
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatalf("decode: %v (body=%s)", err, body)
+	}
+	if len(got) != 1 || got[0].DisplayName != "Coinbase" {
+		t.Errorf("got %+v, want [{Coinbase}]", got)
+	}
+}
+
+func TestLimits_ReturnsConfiguredLimits(t *testing.T) {
+	rig := newAPIRig(t, Config{Limits: Limits{MinUSD: 10, MaxUSD: 100000}})
+	status, body := fireRequest(t, rig.app, "GET", "/v1/bridge/limits", nil)
+	if status != http.StatusOK {
+		t.Fatalf("status = %d, want 200", status)
+	}
+	var got Limits
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatalf("decode: %v (body=%s)", err, body)
+	}
+	if got.MinUSD != 10 || got.MaxUSD != 100000 {
+		t.Errorf("got %+v, want MinUSD=10 MaxUSD=100000", got)
+	}
+}
+
+func TestProfileGET_ReturnsDefaultProfile(t *testing.T) {
+	rig := newAPIRig(t, Config{})
+	status, body := fireRequest(t, rig.app, "GET", "/v1/bridge/profile", nil)
+	if status != http.StatusOK {
+		t.Fatalf("status = %d, want 200", status)
+	}
+	if !strings.Contains(string(body), bridge.BridgeClassicalCompat.Name) {
+		t.Errorf("body = %s, want it to mention the default profile %q", body, bridge.BridgeClassicalCompat.Name)
+	}
+}
+
+func TestSetProfile_OverridesProfile(t *testing.T) {
+	rig := newAPIRig(t, Config{})
+	strict := bridge.LuxStrictPQBridgeProfile
+	rig.api.SetProfile(&strict)
+
+	_, body := fireRequest(t, rig.app, "GET", "/v1/bridge/profile", nil)
+	if !strings.Contains(string(body), strict.Name) {
+		t.Errorf("body = %s, want it to reflect the overridden profile %q", body, strict.Name)
+	}
+}
+
+func TestSetProfile_NilIsNoOp(t *testing.T) {
+	rig := newAPIRig(t, Config{})
+	rig.api.SetProfile(nil)
+	_, body := fireRequest(t, rig.app, "GET", "/v1/bridge/profile", nil)
+	if !strings.Contains(string(body), bridge.BridgeClassicalCompat.Name) {
+		t.Errorf("SetProfile(nil) should leave the default profile intact; body = %s", body)
+	}
+}
+
+// =============================================================================
+// stripPathPrefix — legacy Express-proxy Director.
+// =============================================================================
+
+func TestStripPathPrefix_RewritesPathAndHost(t *testing.T) {
+	target, _ := url.Parse("http://backend.internal:5000")
+	director := stripPathPrefix(target, "/v1/bridge")
+
+	req := httptest.NewRequest(http.MethodGet, "https://bridge.lux.network/v1/bridge/swaps/123", nil)
+	director(req)
+
+	if req.URL.Scheme != "http" || req.URL.Host != "backend.internal:5000" {
+		t.Errorf("scheme/host = %s/%s, want http/backend.internal:5000", req.URL.Scheme, req.URL.Host)
+	}
+	if req.Host != "backend.internal:5000" {
+		t.Errorf("Host header = %q, want backend.internal:5000", req.Host)
+	}
+	if req.URL.Path != "/swaps/123" {
+		t.Errorf("Path = %q, want /swaps/123", req.URL.Path)
+	}
+}
+
+// A request to exactly the prefix (nothing left after trimming) must
+// rewrite to "/", not an empty path — an empty URL.Path on an outbound
+// proxied request is invalid and would 400 against most backends.
+func TestStripPathPrefix_EmptyPathBecomesRoot(t *testing.T) {
+	target, _ := url.Parse("http://backend.internal")
+	director := stripPathPrefix(target, "/v1/bridge")
+
+	req := httptest.NewRequest(http.MethodGet, "https://bridge.lux.network/v1/bridge", nil)
+	director(req)
+
+	if req.URL.Path != "/" {
+		t.Errorf("Path = %q, want / for an exact-prefix match", req.URL.Path)
+	}
+}
+
+// =============================================================================
+// rpcErrToJSONRPC
+// =============================================================================
+
+func TestRPCErrToJSONRPC_PreservesBchainErrorCode(t *testing.T) {
+	err := &bchain.RPCError{Code: -32001, Message: "signer set not found"}
+	resp := rpcErrToJSONRPC(json.RawMessage(`1`), err)
+	if resp.Error == nil || resp.Error.Code != -32001 || resp.Error.Message != "signer set not found" {
+		t.Errorf("resp.Error = %+v, want code=-32001 message=%q", resp.Error, "signer set not found")
+	}
+}
+
+// A *bchain.RPCError with Code==0 (the zero value, e.g. a transport
+// error that never got a real JSON-RPC code) must still map to a
+// valid JSON-RPC error code, not 0 -- 0 isn't a defined JSON-RPC error
+// code and would confuse a strict client.
+func TestRPCErrToJSONRPC_ZeroCodeFallsBackTo32603(t *testing.T) {
+	err := &bchain.RPCError{Code: 0, Message: "transport failed"}
+	resp := rpcErrToJSONRPC(json.RawMessage(`1`), err)
+	if resp.Error.Code != -32603 {
+		t.Errorf("Code = %d, want -32603 fallback for a zero upstream code", resp.Error.Code)
+	}
+}
+
+func TestRPCErrToJSONRPC_GenericErrorFallsBackTo32603(t *testing.T) {
+	resp := rpcErrToJSONRPC(json.RawMessage(`1`), errors.New("connection refused"))
+	if resp.Error == nil || resp.Error.Code != -32603 || resp.Error.Message != "connection refused" {
+		t.Errorf("resp.Error = %+v, want code=-32603 message=%q", resp.Error, "connection refused")
+	}
+	if resp.JSONRPC != "2.0" {
+		t.Errorf("JSONRPC = %q, want 2.0", resp.JSONRPC)
+	}
+}