fix ui

packages/api-common/src/filters/http-exception.filter.ts

@@ -16,6 +16,67 @@ interface ErrorResponseBody {
   path: string;
 }
 
+interface PgDriverError {
+  code?: string;
+  detail?: string;
+  column?: string;
+  message?: string;
+}
+
+const toSentenceCase = (snake: string): string =>
+  snake.replace(/_/g, " ").replace(/\b\w/g, (c) => c.toUpperCase());
+
+/**
+ * Translate common Postgres constraint failures (surfaced by TypeORM as
+ * QueryFailedError, which is NOT an HttpException and would otherwise fall
+ * through as an opaque 500) into actionable 400s. Clients rely on the
+ * "still referenced" wording to show friendly cannot-delete messages.
+ */
+const translatePgError = (
+  driver: PgDriverError,
+): { status: number; message: string } | null => {
+  const detail = driver.detail ?? "";
+  switch (driver.code) {
+    case "23503": {
+      const stillReferenced = detail.match(
+        /is still referenced from table "(.*?)"/,
+      );
+      if (stillReferenced) {
+        const table = toSentenceCase(stillReferenced[1]);
+        return {
+          status: HttpStatus.BAD_REQUEST,
+          message: `Cannot delete: this record is still referenced by ${table}.`,
+        };
+      }
+      const notPresent = detail.match(/is not present in table "(.*?)"/);
+      const entity = toSentenceCase(notPresent?.[1] ?? "referenced entity");
+      return {
+        status: HttpStatus.BAD_REQUEST,
+        message: `The specified ${entity} does not exist.`,
+      };
+    }
+    case "23505": {
+      const pair = detail.match(/\((.*?)\)=\((.*?)\)/);
+      return {
+        status: HttpStatus.BAD_REQUEST,
+        message: `Duplicate entry: '${pair?.[2] ?? "value"}' already exists for '${toSentenceCase(pair?.[1] ?? "field")}'.`,
+      };
+    }
+    case "23502":
+      return {
+        status: HttpStatus.BAD_REQUEST,
+        message: `Missing required field: ${toSentenceCase(driver.column ?? "field")}.`,
+      };
+    case "22P02":
+      return {
+        status: HttpStatus.BAD_REQUEST,
+        message: "Invalid input format (e.g., wrong UUID or number).",
+      };
+    default:
+      return null;
+  }
+};
+
 @Catch()
 export class HttpExceptionFilter implements ExceptionFilter {
   private readonly logger = new Logger(HttpExceptionFilter.name);
@@ -25,13 +86,23 @@ export class HttpExceptionFilter implements ExceptionFilter {
     const response = ctx.getResponse();
     const request = ctx.getRequest();
 
-    const status =
-      exception instanceof HttpException
+    const pgTranslated =
+      (exception as Error)?.name === "QueryFailedError"
+        ? translatePgError(
+            ((exception as { driverError?: PgDriverError }).driverError ??
+              {}) as PgDriverError,
+          )
+        : null;
+
+    const status = pgTranslated
+      ? pgTranslated.status
+      : exception instanceof HttpException
         ? exception.getStatus()
         : HttpStatus.INTERNAL_SERVER_ERROR;
 
-    const messageRaw =
-      exception instanceof HttpException
+    const messageRaw = pgTranslated
+      ? pgTranslated.message
+      : exception instanceof HttpException
         ? exception.getResponse()
         : "Internal server error";