Map contract errors to user-friendly messages

server/src/services/contractErrors.test.ts

@@ -0,0 +1,15 @@
+import { ContractError, TradeNotFoundError, UnauthorizedContractError, parseContractError } from "./contractErrors";
+
+describe("contract error mapping", () => {
+  it("maps Soroban numeric codes to actionable typed errors", () => {
+    expect(parseContractError(new Error("Error(Contract, #3)"))).toBeInstanceOf(TradeNotFoundError);
+    expect(parseContractError("ContractError(2)")).toBeInstanceOf(UnauthorizedContractError);
+  });
+
+  it("uses a safe typed fallback for unknown codes and unrelated failures", () => {
+    const unknown = parseContractError("Error(Contract, #999)");
+    expect(unknown).toBeInstanceOf(ContractError);
+    expect(unknown?.message).toContain("could not be completed");
+    expect(parseContractError(new Error("network unavailable"))).toBeNull();
+  });
+});

server/src/services/contractErrors.ts

@@ -339,5 +339,5 @@ function instantiate(code: number): ContractError {
     return new Ctor();
   }
   // Unknown code — return a generic ContractError so callers still get a typed object
-  return new ContractError(`Unknown contract error (code ${code})`, code);
+  return new ContractError("The transaction could not be completed. Please try again or contact support.", code);
 }