csv-import-body.ts

csv-import-body.tsapps/api/src/common/csv-import-body.tsraw ← common3,091 B← Back to the app
1import type { NextFunction, Request, Response } from "express";
2import { v4 as uuid } from "uuid";
3import { API_PREFIX, MAX_CSV_IMPORT_BODY_BYTES } from "../constants.js";
4 
5/**
6 * T-165 — route-scoped body parser for `POST /databases/:id/import/csv`.
7 *
8 * The CSV import legitimately carries up to a 2 MB JSON body (a 10k-row
9 * file), above the global 256 KB JSON ceiling the webhook contract set as
10 * the app-wide limit. Nest mounts its parsers at `init()` on the SAME
11 * express stack `use()` appends to, so this middleware must be registered
12 * BEFORE the `app.useBodyParser("json", …)` calls in main.ts (and the
13 * integration test helper) to run first.
14 *
15 * It buffers only the import route (everything else falls through untouched
16 * to the 256 KB parser), 413s past `MAX_CSV_IMPORT_BODY_BYTES`, and sets
17 * `req.body`/`req.rawBody` + `req._body = true` so the downstream global
18 * parser skips (body-parser short-circuits on `req._body`). The 413/400
19 * responses use the canonical `{ error: { code, message, requestId } }`
20 * envelope directly (no throw — we run ahead of the Nest pipeline, so the
21 * exception filter is not in scope).
22 */
23 
24const IMPORT_PATH = new RegExp(`^/${API_PREFIX.replace(/\//g, "\\/")}/databases/[^/]+/import/csv$`);
25 
26function envelope(req: Request, res: Response, code: string, status: number, message: string): void {
27  const requestId = (req.headers["x-request-id"] as string | undefined) ?? uuid();
28  req.id = requestId;
29  res.setHeader("x-request-id", requestId);
30  res.status(status).json({ error: { code, message, requestId } });
31}
32 
33export function csvImportBodyParser(req: Request, res: Response, next: NextFunction): void {
34  if (req.method !== "POST" || !IMPORT_PATH.test(req.path)) {
35    next();
36    return;
37  }
38  // Fast path: a declared Content-Length over the cap 413s without buffering.
39  const declared = Number(req.headers["content-length"] ?? 0);
40  if (declared > MAX_CSV_IMPORT_BODY_BYTES) {
41    req.resume();
42    envelope(req, res, "PAYLOAD_TOO_LARGE", 413, `CSV import body exceeds the ${MAX_CSV_IMPORT_BODY_BYTES} byte limit.`);
43    return;
44  }
45  const chunks: Buffer[] = [];
46  let size = 0;
47  let done = false;
48  const finish = (err?: unknown): void => {
49    if (done) return;
50    done = true;
51    if (err) {
52      next(err);
53      return;
54    }
55    const raw = Buffer.concat(chunks);
56    req.rawBody = raw;
57    try {
58      req.body = raw.length > 0 ? JSON.parse(raw.toString("utf8")) : {};
59    } catch {
60      envelope(req, res, "VALIDATION_ERROR", 400, "Request body must be valid JSON.");
61      return;
62    }
63    (req as unknown as Record<string, unknown>)._body = true; // stop the downstream 256 KB parser
64    next();
65  };
66  req.on("data", (chunk: Buffer) => {
67    size += chunk.length;
68    if (size > MAX_CSV_IMPORT_BODY_BYTES) {
69      done = true;
70      req.resume();
71      envelope(req, res, "PAYLOAD_TOO_LARGE", 413, `CSV import body exceeds the ${MAX_CSV_IMPORT_BODY_BYTES} byte limit.`);
72      return;
73    }
74    chunks.push(chunk);
75  });
76  req.on("end", () => finish());
77  req.on("error", (err) => finish(err));
78}
79