fix(api): show clean RPC error messages

server/router/api/v1/connect_handler.go

@@ -4,6 +4,7 @@ import (
 	"net/http"
 
 	"connectrpc.com/connect"
+	"github.com/pkg/errors"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 
@@ -67,7 +68,7 @@ func convertGRPCError(err error) error {
 		return nil
 	}
 	if st, ok := status.FromError(err); ok {
-		return connect.NewError(grpcCodeToConnectCode(st.Code()), err)
+		return connect.NewError(grpcCodeToConnectCode(st.Code()), errors.New(st.Message()))
 	}
 	return connect.NewError(connect.CodeInternal, err)
 }

server/router/api/v1/connect_handler_test.go

@@ -0,0 +1,29 @@
+package v1
+
+import (
+	"strings"
+	"testing"
+
+	"connectrpc.com/connect"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+func TestConvertGRPCErrorUsesStatusMessage(t *testing.T) {
+	const message = "invalid username: must start with a lowercase letter"
+
+	err := convertGRPCError(status.Error(codes.InvalidArgument, message))
+	connectErr, ok := err.(*connect.Error)
+	if !ok {
+		t.Fatalf("convertGRPCError() returned %T, want *connect.Error", err)
+	}
+	if got := connectErr.Code(); got != connect.CodeInvalidArgument {
+		t.Fatalf("convertGRPCError() code = %v, want %v", got, connect.CodeInvalidArgument)
+	}
+	if got := connectErr.Message(); got != message {
+		t.Fatalf("convertGRPCError() message = %q, want %q", got, message)
+	}
+	if strings.Contains(connectErr.Message(), "rpc error:") {
+		t.Fatalf("convertGRPCError() message contains gRPC transport details: %q", connectErr.Message())
+	}
+}

web/src/components/CreateUserDialog.tsx

@@ -74,7 +74,7 @@ function CreateUserDialog({ open, onOpenChange, user: initialUser, onSuccess }:
       onOpenChange(false);
     } catch (error: unknown) {
       handleError(error, toast.error, {
-        context: user ? "Update user" : "Create user",
+        context: isCreating ? "Create user" : "Update user",
         onError: () => requestState.setError(),
       });
     }

web/src/lib/error.ts

@@ -1,4 +1,10 @@
+import { ConnectError } from "@connectrpc/connect";
+
 export function getErrorMessage(error: unknown, fallback = "Unknown error"): string {
+  if (error instanceof ConnectError) {
+    return error.rawMessage || fallback;
+  }
+
   if (error instanceof Error) {
     return error.message;
   }

web/tests/error.test.ts

@@ -0,0 +1,17 @@
+import { Code, ConnectError } from "@connectrpc/connect";
+import { describe, expect, it } from "vitest";
+import { getErrorMessage } from "@/lib/error";
+
+describe("getErrorMessage", () => {
+  it("returns a Connect error message without its status code", () => {
+    const error = new ConnectError("invalid username", Code.InvalidArgument);
+
+    expect(getErrorMessage(error)).toBe("invalid username");
+  });
+
+  it("uses the fallback for an empty Connect error message", () => {
+    const error = new ConnectError("", Code.InvalidArgument);
+
+    expect(getErrorMessage(error, "Request failed")).toBe("Request failed");
+  });
+});