test: harden HTTP scenario execution evidence

tests/integration/http-scenario-catalog.test.ts

@@ -3,9 +3,9 @@ import path from "node:path";
 
 import { afterAll, beforeAll, describe, expect, it } from "vitest";
 
+import { readBoundedBytes } from "../../src/adapters/http/bounded-body-reader.ts";
 import { createContractHttpExecutor } from "../../src/adapters/http/http-execution-v3.ts";
 import {
-  HTTP_EXECUTION_CEILINGS,
   type InstalledHttpContract,
 } from "../../src/contracts/external-contract-runtime.ts";
 import type { CacheScopeSnapshot } from "../../src/contracts/server-state-scope.ts";
@@ -42,6 +42,7 @@ type AttemptTrace = {
   status: AttemptStatus;
   media: string | null;
   pulledBytes: number;
+  appliedCeiling: number | null;
   completed: boolean;
   cancelled: boolean;
 };
@@ -73,6 +74,7 @@ function tracingFetcher(attempts: AttemptTrace[]): typeof fetch {
       status: "PENDING_ABORT",
       media: null,
       pulledBytes: 0,
+      appliedCeiling: null,
       completed: false,
       cancelled: false,
     };
@@ -109,6 +111,9 @@ function tracingFetcher(attempts: AttemptTrace[]): typeof fetch {
         },
         cancel(reason) {
           trace.cancelled = true;
+          // MSW-transferred oversized bodies leave the original cancel promise
+          // permanently pending. Record and request cancellation without making
+          // the proxy response less responsive than the real executor contract.
           void reader.cancel(reason).catch(() => {});
         },
       },
@@ -161,19 +166,6 @@ function bodyDisposition(
   throw new Error(`Response body was neither consumed nor cancelled: ${trace.status}`);
 }
 
-function appliedBodyCeiling(
-  trace: AttemptTrace,
-  operation: InstalledHttpContract<unknown, unknown, unknown>,
-): number {
-  if (typeof trace.status !== "number") return 0;
-  if (operation.contract.acceptedStatuses.includes(trace.status)) {
-    return operation.frontend.responseByteLimit;
-  }
-  return [404, 409, 422, 503].includes(trace.status)
-    ? HTTP_EXECUTION_CEILINGS.problemResponseBytes
-    : 0;
-}
-
 async function waitForHandler(
   ready: Promise<void>,
   executionId: string,
@@ -240,6 +232,15 @@ async function executeScenario(
     }),
     fetcher,
     random: () => 0,
+    readBoundedResponseBytes: async (response, maximumBytes) => {
+      const trace = physicalAttempts.at(-1);
+      if (!trace) throw new Error("Body reader ran before a physical attempt");
+      if (trace.appliedCeiling !== null) {
+        throw new Error("Body reader ran more than once for one attempt");
+      }
+      trace.appliedCeiling = maximumBytes;
+      return readBoundedBytes(response, maximumBytes);
+    },
     sleep: async () => {
       const prior = physicalAttempts.at(-1);
       if (!prior) throw new Error("Retry sleep occurred before an attempt");
@@ -331,7 +332,7 @@ async function executeScenario(
             Object.freeze({
               disposition: bodyDisposition(attempt, outcome),
               pulledBytes: attempt.pulledBytes,
-              ceiling: appliedBodyCeiling(attempt, operation),
+              ceiling: attempt.appliedCeiling ?? 0,
             }),
           ),
         ),