reverse-engineering-anything/src/browser/history/NodeCaptureProcess.ts

import { readFile, writeFile } from "node:fs/promises";
import { z } from "zod";
import { readStableArtifact } from "../../artifacts/readStableArtifact.js";
import { webNetworkCaptureBudgetsSchema } from "../../domain/webNetworkCapture.js";
import { captureBudgets, withCaptureBudgets } from "./CaptureBudgets.js";
import { CaptureFormatError } from "./CaptureFormatError.js";

const requestSchema = z.strictObject({
  snapshot_path: z.string(),
  reply_path: z.string(),
  sensitive_values: z.array(z.string().min(1)),
  budgets: webNetworkCaptureBudgetsSchema,
});

/** Parse untrusted captures in an owned heap and return one complete bounded reply. */
const main = async (): Promise<void> => {
  const format = z.enum(["har", "saz", "qlog"]).parse(process.argv[3]);
  const request = requestSchema.parse(
    JSON.parse(await readFile(process.argv[2] ?? "", "utf8")),
  );
  await withCaptureBudgets(request.budgets, async () => {
    let reply: unknown;
    try {
      let value;
      if (format !== "saz") {
        const { decodeCaptureText } = await import("./CaptureJson.js");
        const decoder =
          format === "har"
            ? (await import("./HarCapture.js")).decodeHarCapture
            : (await import("./QlogCapture.js")).decodeQlogCapture;
        const snapshot = await readStableArtifact(
          request.snapshot_path,
          captureBudgets().inputBytes,
        );
        value = decoder(
          decodeCaptureText(snapshot.bytes, format === "har" ? "HAR" : "qlog"),
          request.sensitive_values,
        );
      } else {
        const { decodeSazCapture } = await import("./SazCapture.js");
        value = await decodeSazCapture(
          request.snapshot_path,
          request.sensitive_values,
        );
      }
      reply = { ok: true, value };
    } catch (cause: unknown) {
      reply =
        cause instanceof CaptureFormatError
          ? {
              ok: false,
              reason: cause.replyReason,
              message: cause.message,
              pointer: cause.pointer,
            }
          : {
              ok: false,
              reason: "decoder",
              message: `Capture decoder failed unexpectedly (${cause instanceof Error ? cause.name : "unknown exception"}).`,
              pointer: "",
            };
    }
    let text = JSON.stringify(reply);
    if (Buffer.byteLength(text) > captureBudgets().outputBytes)
      text = JSON.stringify({
        ok: false,
        reason: "limit",
        message:
          "Capture reply exceeds max_reply_bytes; raise that per-call allowance and retry after cleanup.",
        pointer: "",
      });
    await writeFile(request.reply_path, text, { flag: "wx", mode: 0o600 });
  });
};
await main();