diff --git a/src/__tests__/swallowed-mock-errors.test.ts b/src/__tests__/swallowed-mock-errors.test.ts
new file mode 100644
index 000000000..671b6cbcf
--- /dev/null
+++ b/src/__tests__/swallowed-mock-errors.test.ts
@@ -0,0 +1,27 @@
+/**
+ * The setup files fail a test that logged a caught "missing mock export"
+ * error (`tests/support/swallowed-mock-errors.ts`). Pinned in both
+ * directions, so the check cannot be a no-op.
+ */
+import { describe, expect, it } from "vitest";
+
+import { watchSwallowedMockErrors } from "../../tests/support/swallowed-mock-errors";
+
+describe("the swallowed mock-export check", () => {
+  it("fails on a caught missing-export error that was only logged", () => {
+    const check = watchSwallowedMockErrors();
+    console.warn(
+      "[import] Rollup recompute failed",
+      new Error(
+        '[vitest] No "ROLLUP_FOLD_WINDOW_MS" export is defined on the "@/lib/rollups/measurement-rollups" mock. Did you forget to return it from "vi.mock"?',
+      ),
+    );
+    expect(check).toThrow(/ROLLUP_FOLD_WINDOW_MS/);
+  });
+
+  it("lets every other log line through", () => {
+    const check = watchSwallowedMockErrors();
+    console.warn("[import] Rollup recompute failed", new Error("db down"));
+    expect(check).not.toThrow();
+  });
+});
diff --git a/src/app/api/import/__tests__/route.test.ts b/src/app/api/import/__tests__/route.test.ts
index ef9e668fe..0c334a71e 100644
--- a/src/app/api/import/__tests__/route.test.ts
+++ b/src/app/api/import/__tests__/route.test.ts
@@ -29,7 +29,8 @@ vi.mock("@/lib/auth/audit", () => ({
   auditLog: vi.fn().mockResolvedValue(undefined),
 }));
 
-vi.mock("@/lib/logging/context", () => ({
+vi.mock("@/lib/logging/context", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("@/lib/logging/context")>()),
   annotate: vi.fn(),
 }));
 
diff --git a/src/app/api/import/csv/__tests__/route.test.ts b/src/app/api/import/csv/__tests__/route.test.ts
index 8ce841f24..7dd1431a7 100644
--- a/src/app/api/import/csv/__tests__/route.test.ts
+++ b/src/app/api/import/csv/__tests__/route.test.ts
@@ -50,7 +50,8 @@ vi.mock("@/lib/auth/audit", () => ({
   auditLog: vi.fn().mockResolvedValue(undefined),
 }));
 
-vi.mock("@/lib/logging/context", () => ({
+vi.mock("@/lib/logging/context", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("@/lib/logging/context")>()),
   annotate: vi.fn(),
 }));
 
diff --git a/src/app/api/measurements/__tests__/arrival-wiring.test.ts b/src/app/api/measurements/__tests__/arrival-wiring.test.ts
index ee77a756a..ded4e7f73 100644
--- a/src/app/api/measurements/__tests__/arrival-wiring.test.ts
+++ b/src/app/api/measurements/__tests__/arrival-wiring.test.ts
@@ -52,7 +52,10 @@ vi.mock("@/lib/db", () => {
 });
 
 vi.mock("@/lib/auth/audit", () => ({ auditLog: vi.fn() }));
-vi.mock("@/lib/logging/context", () => ({ annotate: vi.fn() }));
+vi.mock("@/lib/logging/context", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("@/lib/logging/context")>()),
+  annotate: vi.fn(),
+}));
 vi.mock("@/lib/logging/fire-and-forget", () => ({
   fireAndForget: (promise: Promise<unknown>) => void promise.catch(() => {}),
 }));
@@ -83,6 +86,7 @@ vi.mock("@/lib/illness/safety-floor-check", () => ({
 }));
 vi.mock("@/lib/rollups/measurement-rollups", () => ({
   recomputeBucketsForMeasurement: vi.fn(async () => {}),
+  recomputeBucketsForKeys: vi.fn(async () => {}),
   collapseToTypeDayKeys: vi.fn(
     (rows: Array<{ type: string; measuredAt: Date }>) => rows,
   ),
diff --git a/src/app/api/measurements/by-external-ids/__tests__/route.test.ts b/src/app/api/measurements/by-external-ids/__tests__/route.test.ts
index afb091c8e..5cfee6105 100644
--- a/src/app/api/measurements/by-external-ids/__tests__/route.test.ts
+++ b/src/app/api/measurements/by-external-ids/__tests__/route.test.ts
@@ -41,6 +41,7 @@ vi.mock("@/lib/rollups/measurement-rollups", async () => {
   return {
     collapseToTypeDayKeys: actual.collapseToTypeDayKeys,
     recomputeBucketsForMeasurement: vi.fn().mockResolvedValue(undefined),
+    recomputeBucketsForKeys: vi.fn().mockResolvedValue(undefined),
   };
 });
 vi.mock("@/lib/logging/transports", () => ({ emitIfSampled: vi.fn() }));
diff --git a/tests/integration/apple-health-import-ecg.test.ts b/tests/integration/apple-health-import-ecg.test.ts
index 2e5ad1c15..2bd581f7d 100644
--- a/tests/integration/apple-health-import-ecg.test.ts
+++ b/tests/integration/apple-health-import-ecg.test.ts
@@ -31,7 +31,13 @@ vi.mock("@/lib/jobs/boss-instance", () => ({
   getGlobalBoss: vi.fn(() => null),
 }));
 
-vi.mock("@/lib/rollups/measurement-rollups", () => ({
+// The real module with only the fold stubbed, so the import's tail (its fold
+// window, the cache invalidation, the status re-warm) runs as it does in
+// production.
+vi.mock("@/lib/rollups/measurement-rollups", async (importOriginal) => ({
+  ...(await importOriginal<
+    typeof import("@/lib/rollups/measurement-rollups")
+  >()),
   recomputeUserRollups: vi.fn(async () => {}),
 }));
 
diff --git a/tests/integration/environment-setup.ts b/tests/integration/environment-setup.ts
index 601b15715..ac64aff72 100644
--- a/tests/integration/environment-setup.ts
+++ b/tests/integration/environment-setup.ts
@@ -1,6 +1,7 @@
 import { afterEach, beforeEach, inject, vi } from "vitest";
 
 import { quarantineEntryFor } from "../quarantine/quarantine";
+import { watchSwallowedMockErrors } from "../support/swallowed-mock-errors";
 import { prepareWorkerDatabase } from "./worker-database";
 
 // Each worker runs against its own clone of the migrated template (see
@@ -30,10 +31,14 @@ process.env.SESSION_SECRET = "integration-test-session-secret-32-bytes";
  * the worker BEFORE any application module reads it at import time, and a
  * static import here would pull part of the application tree in first.
  */
+/** A swallowed "missing mock export" error fails its test (see the module). */
+const checkSwallowedMockErrors = watchSwallowedMockErrors();
+
 afterEach(async () => {
   const { settleBackgroundTasks } =
     await import("@/lib/logging/background-tasks");
   await settleBackgroundTasks();
+  checkSwallowedMockErrors();
 });
 
 /** The flaky-test quarantine, as in the unit setup (`vitest.setup.ts`). */
diff --git a/tests/support/swallowed-mock-errors.ts b/tests/support/swallowed-mock-errors.ts
new file mode 100644
index 000000000..ae250eafe
--- /dev/null
+++ b/tests/support/swallowed-mock-errors.ts
@@ -0,0 +1,52 @@
+/**
+ * A module mock that leaves out an export the code under test reaches throws
+ * `No "X" export is defined on the "Y" mock` at the call. Where the code
+ * catches and logs that (a best-effort tail, a fail-soft read), the test went
+ * on green while the code path it meant to cover never ran: the Apple Health
+ * import tests mocked the rollup module without its fold window, and the
+ * import's cache invalidation never ran in any of them.
+ *
+ * `watchSwallowedMockErrors` wraps the console once per worker and returns
+ * the check a setup file runs after each test: it throws, failing that test,
+ * when such a line was logged during it.
+ */
+const MISSING_MOCK_EXPORT = /No "[^"]+" export is defined on the "[^"]+" mock/;
+
+function textOf(arg: unknown): string {
+  if (arg instanceof Error) return `${arg.message} ${String(arg.cause ?? "")}`;
+  return typeof arg === "string" ? arg : "";
+}
+
+const SEEN = Symbol.for("healthlog.tests.swallowedMockErrors");
+
+export function watchSwallowedMockErrors(): () => void {
+  // A setup file runs once per test file, and a worker runs many files: the
+  // console is wrapped once per worker, and every file shares what it saw.
+  const slot = globalThis as unknown as { [SEEN]?: string[] };
+  let seen = slot[SEEN];
+  if (!seen) {
+    const lines: string[] = [];
+    seen = lines;
+    slot[SEEN] = lines;
+    for (const level of ["log", "info", "warn", "error"] as const) {
+      const original = console[level].bind(console);
+      console[level] = (...args: unknown[]) => {
+        for (const arg of args) {
+          const match = MISSING_MOCK_EXPORT.exec(textOf(arg));
+          if (match) lines.push(match[0]);
+        }
+        original(...args);
+      };
+    }
+  }
+  const lines = seen;
+  return () => {
+    if (lines.length === 0) return;
+    const found = [...new Set(lines)];
+    lines.length = 0;
+    throw new Error(
+      "a module mock lacks an export the code under test reached, and the " +
+        `error was caught and logged instead of failing: ${found.join("; ")}`,
+    );
+  };
+}
diff --git a/vitest.setup.ts b/vitest.setup.ts
index 7b397bdaa..cb9053f6e 100644
--- a/vitest.setup.ts
+++ b/vitest.setup.ts
@@ -21,6 +21,7 @@
 import { afterEach, beforeEach, vi } from "vitest";
 import { settleBackgroundTasks } from "@/lib/logging/background-tasks";
 import { quarantineEntryFor } from "./tests/quarantine/quarantine";
+import { watchSwallowedMockErrors } from "./tests/support/swallowed-mock-errors";
 import { primeMessages } from "@/lib/i18n/load-locale";
 import enMessages from "./messages/en.json";
 
@@ -41,8 +42,13 @@ primeMessages("en", enMessages);
  * console, which would have thrown away a real signal and left the
  * non-determinism in place. See `src/lib/logging/background-tasks.ts`.
  */
+const checkSwallowedMockErrors = watchSwallowedMockErrors();
+
 afterEach(async () => {
   await settleBackgroundTasks();
+  // A caught "missing mock export" error fails the test it happened in
+  // (`tests/support/swallowed-mock-errors.ts`).
+  checkSwallowedMockErrors();
 });
 
 /**