feat: handle template build error

web/src/api.ts

@@ -1,5 +1,12 @@
 import { promiseOrThrow } from "./lib/errors";
 
+interface ApiErrorResponse {
+	code: string;
+	error: string;
+}
+
+const API_ERROR_BAD_TEMPLATE = "BAD_TEMPLATE";
+
 enum ApiError {
 	NotFound = "NOT_FOUND",
 	BadRequest = "BAD_REQUEST",
@@ -16,10 +23,9 @@ async function fetchApi(
 		() => ApiError.Network,
 	);
 	if (res.status !== 200) {
-		console.log(res.status);
 		switch (res.status) {
-			case 401:
-				throw ApiError.BadRequest;
+			case 400:
+				throw await res.json();
 			case 404:
 				throw ApiError.NotFound;
 			default:
@@ -29,4 +35,15 @@ async function fetchApi(
 	return res;
 }
 
-export { ApiError, fetchApi };
+function isApiErrorResponse(error: unknown): error is ApiErrorResponse {
+	return (
+		error !== null &&
+		error !== undefined &&
+		typeof error === "object" &&
+		"code" in error &&
+		"error" in error
+	);
+}
+
+export { API_ERROR_BAD_TEMPLATE, ApiError, fetchApi, isApiErrorResponse };
+export type { ApiErrorResponse };