tech-log-frontend/tests/unit/public-response-cache.test.ts

import { describe, expect, it } from "vitest";

import type {
  PublicCacheAsset,
  PublicCacheReleaseManifest,
} from "../../src/application/ports/browser-file-storage/cache-storage-ports.ts";
import {
  createDefaultPublicCachePolicy,
  resolvePublicCachePolicy,
  type PublicCacheRuntimePolicy,
} from "../../src/adapters/cache-storage/public-cache-policy.ts";
import {
  computePublicCacheManifestDigestHex,
  createPublicResponseCacheAdapter,
  type PublicCacheMutationLock,
} from "../../src/adapters/cache-storage/public-response-cache-adapter.ts";

class MemoryCache {
  readonly responses: Array<Readonly<{
    request: Request;
    response: Response;
  }>> = [];

  async match(request: RequestInfo | URL): Promise<Response | undefined> {
    const url =
      request instanceof Request ? request.url : new URL(String(request)).href;
    const nativeRequest =
      request instanceof Request ? request : new Request(url);
    return this.responses
      .find(
        (entry) =>
          entry.request.url === url &&
          varyMatches(entry.request, nativeRequest, entry.response),
      )
      ?.response.clone();
  }

  async put(request: RequestInfo | URL, response: Response): Promise<void> {
    const url =
      request instanceof Request ? request.url : new URL(String(request)).href;
    const nativeRequest =
      request instanceof Request ? request.clone() : new Request(url);
    const existing = this.responses.findIndex(
      (entry) =>
        entry.request.url === url &&
        varyMatches(entry.request, nativeRequest, response),
    );
    const entry = {
      request: nativeRequest,
      response: response.clone(),
    };
    if (existing >= 0) this.responses.splice(existing, 1, entry);
    else this.responses.push(entry);
  }
}

function varyMatches(
  storedRequest: Request,
  incomingRequest: Request,
  response: Response,
): boolean {
  const vary = response.headers.get("vary");
  if (!vary) return true;
  return vary
    .split(",")
    .map((name) => name.trim().toLowerCase())
    .every(
      (name) =>
        storedRequest.headers.get(name) ===
        incomingRequest.headers.get(name),
    );
}

class MemoryCacheStorage {
  readonly caches = new Map<string, MemoryCache>();

  async open(name: string): Promise<Cache> {
    let cache = this.caches.get(name);
    if (!cache) {
      cache = new MemoryCache();
      this.caches.set(name, cache);
    }
    return cache as unknown as Cache;
  }

  async keys(): Promise<string[]> {
    return [...this.caches.keys()];
  }

  async delete(name: string): Promise<boolean> {
    return this.caches.delete(name);
  }
}

const immediateLock: PublicCacheMutationLock = {
  async run(_signal, task) {
    return await task();
  },
};

function deferred<Value>() {
  let settle: ((value: Value) => void) | undefined;
  const promise = new Promise<Value>((resolve) => {
    settle = resolve;
  });
  return Object.freeze({
    promise,
    resolve(value: Value): void {
      settle?.(value);
    },
  });
}

async function digestHex(bytes: Uint8Array): Promise<string> {
  const digest = await globalThis.crypto.subtle.digest(
    "SHA-256",
    Uint8Array.from(bytes),
  );
  return [...new Uint8Array(digest)]
    .map((byte) => byte.toString(16).padStart(2, "0"))
    .join("");
}

async function manifestFor(
  releaseRegistryId: string,
  assets: readonly PublicCacheAsset[],
  policy: PublicCacheRuntimePolicy = createDefaultPublicCachePolicy(
    "https://assets.example.test",
  ),
): Promise<PublicCacheReleaseManifest> {
  return {
    releaseRegistryId,
    assets,
    manifestDigestHex: await computePublicCacheManifestDigestHex(
      globalThis.crypto,
      releaseRegistryId,
      assets,
      policy,
    ),
  };
}

describe("public response Cache Storage adapter", () => {
  it("rejects a policy that enables variants but strips Vary", () => {
    const base = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    // STO-03. Enabling variants while dropping Vary from the response
    // allowlist makes every stored variant collide on the same key.
    expect(() =>
      resolvePublicCachePolicy({
        ...base,
        allowedRequestHeaderNames: ["accept", "accept-language"],
        allowedVaryHeaderNames: ["accept-language"],
        allowedResponseHeaderNames: base.allowedResponseHeaderNames.filter(
          (name) => name !== "vary",
        ),
      }),
    ).toThrow(TypeError);
    // The same policy with Vary preserved is accepted.
    expect(() =>
      resolvePublicCachePolicy({
        ...base,
        allowedRequestHeaderNames: ["accept", "accept-language"],
        allowedVaryHeaderNames: ["accept-language"],
      }),
    ).not.toThrow();
  });

  it("restages an evicted entry even when the release marker remains", async () => {
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([9, 9, 9, 9]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/evicted.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const cacheStorage = new MemoryCacheStorage();
    let fetches = 0;
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () => {
        fetches += 1;
        return new Response(bytes, {
          headers: {
            "cache-control": "public",
            "content-type": "application/javascript",
          },
        });
      },
    });
    const manifest = await manifestFor("evicted-release", [asset], policy);
    expect(await adapter.admin.stageRelease(manifest)).toMatchObject({
      ok: true,
    });
    expect(fetches).toBe(1);

    // The browser evicts the payload but leaves the marker behind.
    const cacheName = [...cacheStorage.caches.keys()].find((name) =>
      name.includes("evicted-release"),
    );
    if (!cacheName) throw new Error("staged cache missing");
    const cache = cacheStorage.caches.get(cacheName)!;
    const payloadIndex = cache.responses.findIndex(
      (entry) => entry.request.url === asset.absoluteUrl,
    );
    expect(payloadIndex).toBeGreaterThanOrEqual(0);
    cache.responses.splice(payloadIndex, 1);

    // A marker is a claim, not evidence: restaging must repair.
    expect(await adapter.admin.stageRelease(manifest)).toMatchObject({
      ok: true,
    });
    expect(fetches).toBe(2);
    expect(
      await adapter.admin.activateRelease(
        manifest.releaseRegistryId,
        manifest.manifestDigestHex,
      ),
    ).toMatchObject({ ok: true });
  });

  it("activates a verified prestaged release without a fetcher", async () => {
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([4, 4, 4, 4]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/offline.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const cacheStorage = new MemoryCacheStorage();
    const online = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public",
            "content-type": "application/javascript",
          },
        }),
    });
    const manifest = await manifestFor("offline-release", [asset], policy);
    expect(await online.admin.stageRelease(manifest)).toMatchObject({
      ok: true,
    });

    // STO-05. Activation and cleanup perform no network I/O, so a missing
    // fetcher must not make an offline rollback UNSUPPORTED.
    const offline = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
    });
    expect(
      await offline.admin.activateRelease(
        manifest.releaseRegistryId,
        manifest.manifestDigestHex,
      ),
    ).toMatchObject({ ok: true });
  });

  it("cleans exact owned caches without a fetcher", async () => {
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const cacheStorage = new MemoryCacheStorage();
    const offline = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
    });
    expect(await offline.admin.cleanupOwned()).toMatchObject({
      ok: true,
    });
  });

  it("stages, re-verifies and atomically activates an exact release", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const bytes = new Uint8Array([1, 2, 3, 4]);
    const url = "https://assets.example.test/app.js?v=release-1";
    const asset: PublicCacheAsset = {
      absoluteUrl: url,
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const policy: PublicCacheRuntimePolicy = {
      ...createDefaultPublicCachePolicy(
        "https://assets.example.test",
      ),
      allowedQueryParameterNames: ["v"],
      isQueryParameterValueAllowed: (name, value) =>
        name === "v" && /^release-\d+$/u.test(value),
    };
    const manifest = await manifestFor("release-1", [asset], policy);
    const observations: unknown[] = [];
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      now: () => 10,
      observer: (event) => observations.push(event),
      fetcher: async () =>
        new Response(bytes, {
          status: 200,
          headers: {
            "cache-control": "public, max-age=31536000, immutable",
            "content-type": "application/javascript",
            "x-user-id": "must-not-be-persisted",
          },
        }),
    });

    const staged = await adapter.admin.stageRelease(manifest);
    expect(staged).toEqual({
      ok: true,
      value: {
        releaseRegistryId: "release-1",
        entryCount: 1,
        totalBytes: 4,
        stagedAtEpochMs: 10,
      },
    });
    expect(
      await adapter.admin.activateRelease(
        manifest.releaseRegistryId,
        manifest.manifestDigestHex,
      ),
    ).toMatchObject({ ok: true });

    const match = await adapter.responses.matchActiveExact({
      absoluteUrl: url,
    });
    expect(match.ok).toBe(true);
    if (!match.ok || !match.value) throw new Error("cache miss");
    const chunks: number[] = [];
    for await (const chunk of match.value.body.stream(
      new AbortController().signal,
    )) {
      expect(chunk.ok).toBe(true);
      if (chunk.ok) chunks.push(...chunk.value);
    }
    expect(chunks).toEqual([1, 2, 3, 4]);
    expect(match.value.headers.map(([name]) => name)).not.toContain(
      "x-user-id",
    );

    expect(
      await adapter.responses.matchActiveExact({
        absoluteUrl:
          "https://assets.example.test/app.js?v=release-2",
      }),
    ).toEqual({ ok: true, value: null });
    expect(JSON.stringify(observations)).not.toContain(url);
    expect(JSON.stringify(observations)).not.toContain(
      manifest.manifestDigestHex,
    );
  });

  it("snapshots the complete manifest before asynchronous digest verification", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([2, 4, 6, 8]);
    const asset = {
      absoluteUrl: "https://assets.example.test/snapshot-crypto.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256" as const,
        digestHex: await digestHex(bytes),
      },
    };
    const signed = await manifestFor(
      "snapshot-crypto",
      [asset],
      policy,
    );
    const manifest = {
      releaseRegistryId: signed.releaseRegistryId,
      assets: [asset],
      manifestDigestHex: signed.manifestDigestHex,
    };
    const digestStarted = deferred<void>();
    const releaseDigest = deferred<void>();
    let delayFirstDigest = true;
    const realCrypto = globalThis.crypto;
    const delayedCrypto = {
      subtle: {
        async digest(
          algorithm: AlgorithmIdentifier,
          data: BufferSource,
        ): Promise<ArrayBuffer> {
          if (delayFirstDigest) {
            delayFirstDigest = false;
            digestStarted.resolve(undefined);
            await releaseDigest.promise;
          }
          return await realCrypto.subtle.digest(algorithm, data);
        },
      },
    } as unknown as Crypto;
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: delayedCrypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });

    const staging = adapter.admin.stageRelease(manifest);
    await digestStarted.promise;
    manifest.releaseRegistryId = "mutated-during-crypto";
    manifest.manifestDigestHex = "0".repeat(64);
    manifest.assets[0]!.absoluteUrl =
      "https://assets.example.test/mutated-crypto.js";
    releaseDigest.resolve(undefined);

    await expect(staging).resolves.toMatchObject({
      ok: true,
      value: { releaseRegistryId: "snapshot-crypto" },
    });
    await expect(
      adapter.admin.activateRelease(
        signed.releaseRegistryId,
        signed.manifestDigestHex,
      ),
    ).resolves.toMatchObject({ ok: true });
  });

  it("keeps the original stage signal while digest verification is pending", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([8, 6, 4, 2]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/snapshot-signal.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const manifest = await manifestFor(
      "snapshot-signal",
      [asset],
      policy,
    );
    const digestStarted = deferred<void>();
    const releaseDigest = deferred<void>();
    let delayFirstDigest = true;
    const realCrypto = globalThis.crypto;
    const delayedCrypto = {
      subtle: {
        async digest(
          algorithm: AlgorithmIdentifier,
          data: BufferSource,
        ): Promise<ArrayBuffer> {
          if (delayFirstDigest) {
            delayFirstDigest = false;
            digestStarted.resolve(undefined);
            await releaseDigest.promise;
          }
          return await realCrypto.subtle.digest(algorithm, data);
        },
      },
    } as unknown as Crypto;
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: delayedCrypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });
    const original = new AbortController();
    const replacement = new AbortController();
    const options = { signal: original.signal };

    const staging = adapter.admin.stageRelease(manifest, options);
    await digestStarted.promise;
    options.signal = replacement.signal;
    original.abort();
    releaseDigest.resolve(undefined);

    await expect(staging).resolves.toMatchObject({
      ok: false,
      error: { code: "ABORTED" },
    });
    await expect(cacheStorage.keys()).resolves.toEqual([]);
  });

  /**
   * NS-08. Handing the signal to each `Request` only asked a cooperative fetch
   * to stop. A stream that ignored it held the mutation lock forever, and work
   * that finished after the abort still wrote its asset and its marker.
   */
  it("does not wait for a non-cooperative fetch after the caller aborts", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([1, 2, 3, 4]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/never-settles.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: { algorithm: "SHA-256", digestHex: await digestHex(bytes) },
    };
    const manifest = await manifestFor("never-settles", [asset], policy);
    const fetchStarted = deferred<void>();
    let locksHeld = 0;
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: {
        async run(signal, operation) {
          locksHeld += 1;
          try {
            return await operation();
          } finally {
            locksHeld -= 1;
          }
        },
      },
      policy,
      fetcher: () => {
        fetchStarted.resolve(undefined);
        // Ignores the signal entirely.
        return new Promise<Response>(() => {});
      },
    });
    const controller = new AbortController();

    const staging = adapter.admin.stageRelease(manifest, {
      signal: controller.signal,
    });
    await fetchStarted.promise;
    controller.abort();

    await expect(staging).resolves.toMatchObject({
      ok: false,
      error: { code: "ABORTED" },
    });
    expect(locksHeld).toBe(0);
    await expect(cacheStorage.keys()).resolves.toEqual([]);
  });

  it("writes neither asset nor marker when a digest completes after the abort", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([9, 9, 9, 9]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/late-digest.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: { algorithm: "SHA-256", digestHex: await digestHex(bytes) },
    };
    const manifest = await manifestFor("late-digest", [asset], policy);
    const digestStarted = deferred<void>();
    const releaseDigest = deferred<void>();
    let delayFirstDigest = true;
    const realCrypto = globalThis.crypto;
    const delayedCrypto = {
      subtle: {
        async digest(
          algorithm: AlgorithmIdentifier,
          data: BufferSource,
        ): Promise<ArrayBuffer> {
          if (delayFirstDigest) {
            delayFirstDigest = false;
            digestStarted.resolve(undefined);
            await releaseDigest.promise;
          }
          return await realCrypto.subtle.digest(algorithm, data);
        },
      },
    } as unknown as Crypto;
    let puts = 0;
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: new Proxy(cacheStorage, {
        get(target, key, receiver) {
          if (key === "open") {
            return async (name: string) => {
              const cache = await target.open(name);
              return new Proxy(cache, {
                get(cacheTarget, cacheKey, cacheReceiver) {
                  if (cacheKey === "put") {
                    return async (...args: readonly unknown[]) => {
                      puts += 1;
                      return await (
                        cacheTarget.put as (
                          ...values: readonly unknown[]
                        ) => Promise<void>
                      )(...args);
                    };
                  }
                  return Reflect.get(cacheTarget, cacheKey, cacheReceiver);
                },
              });
            };
          }
          return Reflect.get(target, key, receiver);
        },
      }) as unknown as CacheStorage,
      crypto: delayedCrypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });
    const controller = new AbortController();

    const staging = adapter.admin.stageRelease(manifest, {
      signal: controller.signal,
    });
    await digestStarted.promise;
    controller.abort();
    releaseDigest.resolve(undefined);

    await expect(staging).resolves.toMatchObject({
      ok: false,
      error: { code: "ABORTED" },
    });
    // Neither the asset nor the activation marker may be written by work the
    // abort already disowned.
    expect(puts).toBe(0);
  });

  it("keeps the original activation signal while waiting for the mutation lock", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([7]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/activate-signal.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const manifest = await manifestFor("activate-signal", [asset], policy);
    const lockStarted = deferred<void>();
    const releaseLock = deferred<void>();
    let delayLock = false;
    const lock: PublicCacheMutationLock = {
      async run(_signal, task) {
        if (delayLock) {
          lockStarted.resolve(undefined);
          await releaseLock.promise;
        }
        return await task();
      },
    };
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: lock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });
    await expect(adapter.admin.stageRelease(manifest)).resolves.toMatchObject({
      ok: true,
    });

    delayLock = true;
    const original = new AbortController();
    const replacement = new AbortController();
    const options = { signal: original.signal };
    const activation = adapter.admin.activateRelease(
      manifest.releaseRegistryId,
      manifest.manifestDigestHex,
      options,
    );
    await lockStarted.promise;
    options.signal = replacement.signal;
    original.abort();
    releaseLock.resolve(undefined);

    await expect(activation).resolves.toMatchObject({
      ok: false,
      error: { code: "ABORTED" },
    });
    expect(await cacheStorage.keys()).not.toContain("ca-public-v1:control");
  });

  it("keeps the original lookup signal while cache discovery is pending", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const baseKeys = cacheStorage.keys.bind(cacheStorage);
    const lookupStarted = deferred<void>();
    const releaseLookup = deferred<void>();
    let delayKeys = false;
    cacheStorage.keys = async () => {
      if (delayKeys) {
        lookupStarted.resolve(undefined);
        await releaseLookup.promise;
        delayKeys = false;
      }
      return await baseKeys();
    };
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([9]);
    const absoluteUrl =
      "https://assets.example.test/lookup-signal.js";
    const asset: PublicCacheAsset = {
      absoluteUrl,
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const manifest = await manifestFor("lookup-signal", [asset], policy);
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });
    await expect(adapter.admin.stageRelease(manifest)).resolves.toMatchObject({
      ok: true,
    });
    await expect(
      adapter.admin.activateRelease(
        manifest.releaseRegistryId,
        manifest.manifestDigestHex,
      ),
    ).resolves.toMatchObject({ ok: true });

    delayKeys = true;
    const original = new AbortController();
    const replacement = new AbortController();
    const request = { absoluteUrl, signal: original.signal };
    const lookup = adapter.responses.matchActiveExact(request);
    await lookupStarted.promise;
    request.signal = replacement.signal;
    original.abort();
    releaseLookup.resolve(undefined);

    await expect(lookup).resolves.toMatchObject({
      ok: false,
      error: { code: "ABORTED" },
    });
  });

  it("captures runtime dependencies when the adapter is composed", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([5, 4, 3, 2, 1]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/dependency-snapshot.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const manifest = await manifestFor(
      "dependency-snapshot",
      [asset],
      policy,
    );
    const mutableSubtle = {
      async digest(
        algorithm: AlgorithmIdentifier,
        data: BufferSource,
      ): Promise<ArrayBuffer> {
        return await globalThis.crypto.subtle.digest(algorithm, data);
      },
    };
    const mutableCrypto = {
      subtle: mutableSubtle,
    } as unknown as Crypto;
    const mutationLock: PublicCacheMutationLock = {
      async run(_signal, task) {
        return await task();
      },
    };
    const dependencies = {
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: mutableCrypto,
      mutationLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          status: 200,
          headers: {
            "cache-control": "public, max-age=31536000, immutable",
            "content-type": "application/javascript",
          },
        }),
    };
    const adapter = createPublicResponseCacheAdapter(dependencies);

    dependencies.fetcher = async () => {
      throw new TypeError("mutated dependency must not be observed");
    };
    cacheStorage.keys = async () => {
      throw new TypeError("mutated CacheStorage method must not be observed");
    };
    mutationLock.run = async () => {
      throw new TypeError("mutated lock method must not be observed");
    };
    mutableSubtle.digest = async () => {
      throw new TypeError("mutated crypto method must not be observed");
    };

    await expect(
      adapter.admin.stageRelease(manifest),
    ).resolves.toMatchObject({
      ok: true,
      value: { releaseRegistryId: "dependency-snapshot" },
    });
  });

  it("keeps the verified manifest snapshot while waiting for the mutation lock", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([1, 3, 5, 7]);
    const asset = {
      absoluteUrl: "https://assets.example.test/snapshot-lock.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256" as const,
        digestHex: await digestHex(bytes),
      },
    };
    const signed = await manifestFor("snapshot-lock", [asset], policy);
    const manifest = {
      releaseRegistryId: signed.releaseRegistryId,
      assets: [asset],
      manifestDigestHex: signed.manifestDigestHex,
    };
    const lockStarted = deferred<void>();
    const releaseLock = deferred<void>();
    const delayedLock: PublicCacheMutationLock = {
      async run(_signal, task) {
        lockStarted.resolve(undefined);
        await releaseLock.promise;
        return await task();
      },
    };
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: delayedLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });

    const staging = adapter.admin.stageRelease(manifest);
    await lockStarted.promise;
    manifest.releaseRegistryId = "mutated-during-lock";
    manifest.manifestDigestHex = "f".repeat(64);
    manifest.assets[0]!.absoluteUrl =
      "https://assets.example.test/mutated-lock.js";
    releaseLock.resolve(undefined);

    await expect(staging).resolves.toMatchObject({
      ok: true,
      value: { releaseRegistryId: "snapshot-lock" },
    });
    await expect(
      adapter.admin.activateRelease(
        signed.releaseRegistryId,
        signed.manifestDigestHex,
      ),
    ).resolves.toMatchObject({ ok: true });
  });

  it("fails closed for private responses and deletes the incomplete candidate", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const bytes = new Uint8Array([9]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/private.json",
      expectedByteLength: 1,
      expectedContentType: "application/json",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const manifest = await manifestFor("release-private", [asset]);
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy: createDefaultPublicCachePolicy(
        "https://assets.example.test",
      ),
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "private, max-age=60",
            "content-type": "application/json",
          },
        }),
    });

    expect(await adapter.admin.stageRelease(manifest)).toMatchObject({
      ok: false,
      error: { code: "POLICY_REJECTED" },
    });
    expect(await cacheStorage.keys()).toEqual([]);
  });

  it("binds the exact expected Content-Type into the signed manifest and cached response", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([7, 7]);
    const baseAsset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/content.bin",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/json",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const jsonManifest = await manifestFor(
      "content-json",
      [baseAsset],
      policy,
    );
    const javascriptManifest = await manifestFor(
      "content-js",
      [
        {
          ...baseAsset,
          expectedContentType: "application/javascript",
        },
      ],
      policy,
    );
    expect(jsonManifest.manifestDigestHex).not.toBe(
      javascriptManifest.manifestDigestHex,
    );

    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });
    expect(
      await adapter.admin.stageRelease(jsonManifest),
    ).toMatchObject({
      ok: false,
      error: { code: "INTEGRITY_FAILED" },
    });
    expect(await cacheStorage.keys()).toEqual([]);
  });

  it("deletes only caches owned by its prefix", async () => {
    const cacheStorage = new MemoryCacheStorage();
    await cacheStorage.open("unrelated-cache");
    await cacheStorage.open("ca-public-v1:stale");
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy: createDefaultPublicCachePolicy(
        "https://assets.example.test",
      ),
      fetcher: async () => new Response(),
    });

    expect(await adapter.admin.cleanupOwned()).toMatchObject({
      ok: true,
      value: { deletedOwnedCaches: 1 },
    });
    expect(await cacheStorage.keys()).toContain("unrelated-cache");
  });

  it("does not let callers retain an unreferenced staged release", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([3, 1, 4]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/orphan.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const manifest = await manifestFor("orphan-release", [asset], policy);
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
        }),
    });
    await expect(adapter.admin.stageRelease(manifest)).resolves.toMatchObject({
      ok: true,
    });

    const legacyCallerRetention = {
      retainReleaseRegistryIds: [manifest.releaseRegistryId],
    } as unknown as Parameters<
      typeof adapter.admin.cleanupOwned
    >[0];
    await expect(
      adapter.admin.cleanupOwned(legacyCallerRetention),
    ).resolves.toMatchObject({
      ok: true,
      value: {
        deletedOwnedCaches: 1,
        retainedOwnedCaches: 0,
      },
    });
    await expect(cacheStorage.keys()).resolves.toEqual([]);
  });

  it("keeps the original cleanup signal while waiting for the mutation lock", async () => {
    const cacheStorage = new MemoryCacheStorage();
    await cacheStorage.open("ca-public-v1:stale");
    const lockStarted = deferred<void>();
    const releaseLock = deferred<void>();
    const lock: PublicCacheMutationLock = {
      async run(_signal, task) {
        lockStarted.resolve(undefined);
        await releaseLock.promise;
        return await task();
      },
    };
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: lock,
      policy: createDefaultPublicCachePolicy(
        "https://assets.example.test",
      ),
      fetcher: async () => new Response(),
    });
    const original = new AbortController();
    const replacement = new AbortController();
    const request = { signal: original.signal };

    const cleanup = adapter.admin.cleanupOwned(request);
    await lockStarted.promise;
    request.signal = replacement.signal;
    original.abort();
    releaseLock.resolve(undefined);

    await expect(cleanup).resolves.toMatchObject({
      ok: false,
      error: { code: "ABORTED" },
    });
    await expect(cacheStorage.keys()).resolves.toContain(
      "ca-public-v1:stale",
    );
  });

  it("cancels oversized streamed control JSON before reading the remainder", async () => {
    let pulls = 0;
    let cancelled = false;
    const oversizedControlResponse = new Response(
      new ReadableStream<Uint8Array>({
        pull(controller) {
          pulls += 1;
          if (pulls === 1) {
            controller.enqueue(new Uint8Array(1_500_000));
            return;
          }
          if (pulls === 2) {
            controller.enqueue(new Uint8Array(1_000_000));
            return;
          }
          controller.enqueue(new Uint8Array([1]));
        },
        cancel() {
          cancelled = true;
        },
      }),
      {
        headers: { "content-type": "application/json" },
      },
    );
    const candidate = {
      async match(): Promise<Response> {
        return oversizedControlResponse;
      },
      async put(): Promise<void> {},
    };
    const cacheStorage = {
      async open(): Promise<Cache> {
        return candidate as unknown as Cache;
      },
      async keys(): Promise<string[]> {
        return ["ca-public-v1:release:oversized:control"];
      },
      async delete(): Promise<boolean> {
        return false;
      },
    };
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      policy: createDefaultPublicCachePolicy(
        "https://assets.example.test",
      ),
    });

    await expect(adapter.admin.inspect()).resolves.toMatchObject({
      ok: true,
      value: {
        ownedCacheCount: 1,
        unreadableOwnedCacheCount: 1,
      },
    });
    // A stream may prefetch one chunk at its high-water mark, but the
    // consumer must not continue pulling the remaining source.
    expect(pulls).toBeLessThanOrEqual(3);
    expect(cancelled).toBe(true);
  });

  it("retains the active and previous verified release for rollback", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bodies = new Map<string, Uint8Array>();
    const manifests: PublicCacheReleaseManifest[] = [];
    for (const release of ["release-a", "release-b"]) {
      const url = `https://assets.example.test/${release}.js`;
      const bytes = new TextEncoder().encode(release);
      bodies.set(url, bytes);
      const asset: PublicCacheAsset = {
        absoluteUrl: url,
        expectedByteLength: bytes.byteLength,
        expectedContentType: "application/javascript",
        integrity: {
          algorithm: "SHA-256",
          digestHex: await digestHex(bytes),
        },
      };
      manifests.push(await manifestFor(release, [asset], policy));
    }
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async (request) =>
        new Response(
          Uint8Array.from(
            bodies.get(request.url) ?? new Uint8Array(),
          ),
          {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/javascript",
          },
          },
        ),
    });
    for (const manifest of manifests) {
      expect(await adapter.admin.stageRelease(manifest)).toMatchObject({
        ok: true,
      });
      expect(
        await adapter.admin.activateRelease(
          manifest.releaseRegistryId,
          manifest.manifestDigestHex,
        ),
      ).toMatchObject({ ok: true });
    }
    await cacheStorage.open("ca-public-v1:stale");

    const cleaned = await adapter.admin.cleanupOwned();
    expect(cleaned).toMatchObject({
      ok: true,
      value: {
        deletedOwnedCaches: 1,
        retainedOwnedCaches: 3,
      },
    });
    const releaseCaches = (await cacheStorage.keys()).filter((name) =>
      name.startsWith("ca-public-v1:release:"),
    );
    expect(releaseCaches).toHaveLength(2);
  });

  it("requires allowlisted exact query values and rejects duplicates", async () => {
    const base = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const policy: PublicCacheRuntimePolicy = {
      ...base,
      allowedQueryParameterNames: ["v"],
      isQueryParameterValueAllowed: (name, value) =>
        name === "v" && /^r\d+$/u.test(value),
    };
    const bytes = new Uint8Array([1]);
    const allowed: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/app.js?v=r1",
      expectedByteLength: 1,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    await expect(
      manifestFor(
        "duplicate-query",
        [
          {
            ...allowed,
            absoluteUrl:
              "https://assets.example.test/app.js?v=r1&v=r2",
          },
        ],
        policy,
      ),
    ).rejects.toThrow();
    await expect(
      manifestFor(
        "signed-query",
        [
          {
            ...allowed,
            absoluteUrl:
              "https://assets.example.test/app.js?sig=secret",
          },
        ],
        policy,
      ),
    ).rejects.toThrow();
  });

  it("supports exact Vary variants and rejects missing or extra Vary", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const base = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const policy: PublicCacheRuntimePolicy = {
      ...base,
      allowedVaryHeaderNames: ["accept-language"],
    };
    const url = "https://assets.example.test/messages.json";
    const variants = [
      { language: "en", bytes: new TextEncoder().encode("hello") },
      { language: "ko", bytes: new TextEncoder().encode("안녕") },
    ];
    const assets = await Promise.all(
      variants.map(async ({ language, bytes }) => ({
        absoluteUrl: url,
        expectedByteLength: bytes.byteLength,
        expectedContentType: "application/json",
        requestHeaders: [["accept-language", language]] as const,
        integrity: {
          algorithm: "SHA-256" as const,
          digestHex: await digestHex(bytes),
        },
      })),
    );
    const manifest = await manifestFor("language-release", assets, policy);
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async (request) => {
        const variant = variants.find(
          ({ language }) =>
            language === request.headers.get("accept-language"),
        );
        return new Response(variant?.bytes, {
          headers: {
            "cache-control": "public, max-age=60",
            "content-type": "application/json",
            vary: "Accept-Language",
          },
        });
      },
    });
    expect(await adapter.admin.stageRelease(manifest)).toMatchObject({
      ok: true,
    });
    expect(
      await adapter.admin.activateRelease(
        manifest.releaseRegistryId,
        manifest.manifestDigestHex,
      ),
    ).toMatchObject({ ok: true });
    for (const variant of variants) {
      const match = await adapter.responses.matchActiveExact({
        absoluteUrl: url,
        requestHeaders: [["accept-language", variant.language]],
      });
      expect(match).toMatchObject({ ok: true });
      if (!match.ok || !match.value) throw new Error("variant cache miss");
      const chunks: number[] = [];
      for await (const chunk of match.value.body.stream(
        new AbortController().signal,
      )) {
        expect(chunk.ok).toBe(true);
        if (chunk.ok) chunks.push(...chunk.value);
      }
      expect(chunks).toEqual([...variant.bytes]);
    }

    const missingVary = createPublicResponseCacheAdapter({
      cacheStorage: new MemoryCacheStorage() as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(variants[0]!.bytes, {
          headers: {
            "cache-control": "public",
            "content-type": "application/json",
          },
        }),
    });
    expect(
      await missingVary.admin.stageRelease(
        await manifestFor("missing-vary", [assets[0]!], policy),
      ),
    ).toMatchObject({
      ok: false,
      error: { code: "POLICY_REJECTED" },
    });

    const noHeaderAsset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/plain.json",
      expectedByteLength: variants[0]!.bytes.byteLength,
      expectedContentType: "application/json",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(variants[0]!.bytes),
      },
    };
    const extraVary = createPublicResponseCacheAdapter({
      cacheStorage: new MemoryCacheStorage() as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () =>
        new Response(variants[0]!.bytes, {
          headers: {
            "cache-control": "public",
            "content-type": "application/json",
            vary: "Accept-Language",
          },
        }),
    });
    expect(
      await extraVary.admin.stageRelease(
        await manifestFor("extra-vary", [noHeaderAsset], policy),
      ),
    ).toMatchObject({
      ok: false,
      error: { code: "POLICY_REJECTED" },
    });
  });

  it("propagates AbortSignal to fetch and cancels a pending body read", async () => {
    const cacheStorage = new MemoryCacheStorage();
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([1]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/slow.js",
      expectedByteLength: 1,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const manifest = await manifestFor("abort-release", [asset], policy);
    let networkSignal: AbortSignal | undefined;
    let bodyCancelled = false;
    let signalCaptured: (() => void) | undefined;
    const fetchStarted = new Promise<void>((resolve) => {
      signalCaptured = resolve;
    });
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async (request) => {
        networkSignal = request.signal;
        signalCaptured?.();
        return new Response(
          new ReadableStream<Uint8Array>({
            cancel() {
              bodyCancelled = true;
            },
          }),
          {
            headers: {
              "cache-control": "public",
              "content-type": "application/javascript",
            },
          },
        );
      },
    });
    const controller = new AbortController();
    const staged = adapter.admin.stageRelease(manifest, {
      signal: controller.signal,
    });
    await fetchStarted;
    controller.abort();

    expect(await staged).toMatchObject({
      ok: false,
      error: { code: "ABORTED" },
    });
    expect(networkSignal?.aborted).toBe(true);
    expect(bodyCancelled).toBe(true);
    expect(await cacheStorage.keys()).toEqual([]);
  });
});

/**
 * STO-RR-04 / STO-RR-05. A release cache that is currently serving traffic is
 * the last thing a repair may destroy. A transient marker read failure is not
 * evidence of damage, and a repair that has not yet fetched anything has not
 * yet earned the right to delete what still works.
 */
describe("public response cache repair is failure-atomic", () => {
  async function stagedRelease(releaseRegistryId: string) {
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const firstBytes = new Uint8Array([1, 1, 1, 1]);
    const secondBytes = new Uint8Array([2, 2, 2, 2]);
    const assets: readonly PublicCacheAsset[] = [
      {
        absoluteUrl: "https://assets.example.test/first.js",
        expectedByteLength: firstBytes.byteLength,
        expectedContentType: "application/javascript",
        integrity: {
          algorithm: "SHA-256",
          digestHex: await digestHex(firstBytes),
        },
      },
      {
        absoluteUrl: "https://assets.example.test/second.js",
        expectedByteLength: secondBytes.byteLength,
        expectedContentType: "application/javascript",
        integrity: {
          algorithm: "SHA-256",
          digestHex: await digestHex(secondBytes),
        },
      },
    ];
    const bodies = new Map<string, Uint8Array>([
      [assets[0]!.absoluteUrl, firstBytes],
      [assets[1]!.absoluteUrl, secondBytes],
    ]);
    const cacheStorage = new MemoryCacheStorage();
    const fetchLog: string[] = [];
    let failFrom: string | null = null;
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async (request: Request) => {
        fetchLog.push(request.url);
        if (failFrom !== null && request.url === failFrom) {
          throw new TypeError("network is down");
        }
        const body = bodies.get(request.url);
        if (!body) throw new TypeError(`unknown asset ${request.url}`);
        return new Response(Uint8Array.from(body), {
          headers: {
            "cache-control": "public",
            "content-type": "application/javascript",
          },
        });
      },
    });
    const manifest = await manifestFor(releaseRegistryId, assets, policy);
    expect(await adapter.admin.stageRelease(manifest)).toMatchObject({
      ok: true,
    });
    expect(
      await adapter.admin.activateRelease(
        manifest.releaseRegistryId,
        manifest.manifestDigestHex,
      ),
    ).toMatchObject({ ok: true });
    const cacheName = [...cacheStorage.caches.keys()].find((name) =>
      name.includes(releaseRegistryId),
    );
    if (!cacheName) throw new Error("staged cache missing");

    return {
      adapter,
      assets,
      cacheName,
      cacheStorage,
      fetchLog,
      manifest,
      setFailure(url: string | null) {
        failFrom = url;
      },
    };
  }

  it("does not delete an active candidate when the marker read fails transiently", async () => {
    const release = await stagedRelease("transient-marker");
    const cache = release.cacheStorage.caches.get(release.cacheName)!;
    const realMatch = cache.match.bind(cache);
    let markerReads = 0;
    const assetUrls = new Set(release.assets.map((asset) => asset.absoluteUrl));
    cache.match = async (request: RequestInfo | URL) => {
      const url =
        request instanceof Request ? request.url : String(request);
      if (!assetUrls.has(url)) {
        markerReads += 1;
        throw new DOMException("Storage is busy", "InvalidStateError");
      }
      return await realMatch(request);
    };

    const restaged = await release.adapter.admin.stageRelease(release.manifest);

    expect(markerReads).toBeGreaterThan(0);
    expect(restaged.ok).toBe(false);
    expect(release.cacheStorage.caches.has(release.cacheName)).toBe(true);
    cache.match = realMatch;
    expect(
      await release.adapter.responses.matchActiveExact({
        absoluteUrl: release.assets[0]!.absoluteUrl,
      }),
    ).toMatchObject({ ok: true });
  });

  it("keeps every healthy asset when one repair fetch fails", async () => {
    const release = await stagedRelease("partial-repair");
    const cache = release.cacheStorage.caches.get(release.cacheName)!;
    // Corrupt only the first asset's stored bytes.
    const corrupted = cache.responses.findIndex(
      (entry) => entry.request.url === release.assets[0]!.absoluteUrl,
    );
    expect(corrupted).toBeGreaterThanOrEqual(0);
    cache.responses.splice(corrupted, 1);

    release.setFailure(release.assets[0]!.absoluteUrl);
    const restaged = await release.adapter.admin.stageRelease(release.manifest);
    expect(restaged.ok).toBe(false);

    // The cache still exists and the healthy asset is still served.
    expect(release.cacheStorage.caches.has(release.cacheName)).toBe(true);
    expect(
      await release.adapter.responses.matchActiveExact({
        absoluteUrl: release.assets[1]!.absoluteUrl,
      }),
    ).toMatchObject({ ok: true });
  });

  it("still removes a candidate this call created when staging fails", async () => {
    const policy = createDefaultPublicCachePolicy(
      "https://assets.example.test",
    );
    const bytes = new Uint8Array([7, 7, 7, 7]);
    const asset: PublicCacheAsset = {
      absoluteUrl: "https://assets.example.test/fresh.js",
      expectedByteLength: bytes.byteLength,
      expectedContentType: "application/javascript",
      integrity: {
        algorithm: "SHA-256",
        digestHex: await digestHex(bytes),
      },
    };
    const cacheStorage = new MemoryCacheStorage();
    const adapter = createPublicResponseCacheAdapter({
      cacheStorage: cacheStorage as unknown as CacheStorage,
      crypto: globalThis.crypto,
      mutationLock: immediateLock,
      policy,
      fetcher: async () => {
        throw new TypeError("network is down");
      },
    });
    const manifest = await manifestFor("fresh-release", [asset], policy);

    expect(await adapter.admin.stageRelease(manifest)).toMatchObject({
      ok: false,
    });
    expect(await cacheStorage.keys()).toEqual([]);
  });

  it("repairs an evicted asset in place and keeps the release usable", async () => {
    const release = await stagedRelease("in-place-repair");
    const cache = release.cacheStorage.caches.get(release.cacheName)!;
    const evicted = cache.responses.findIndex(
      (entry) => entry.request.url === release.assets[1]!.absoluteUrl,
    );
    cache.responses.splice(evicted, 1);

    expect(
      await release.adapter.admin.stageRelease(release.manifest),
    ).toMatchObject({ ok: true });
    expect(
      await release.adapter.responses.matchActiveExact({
        absoluteUrl: release.assets[1]!.absoluteUrl,
      }),
    ).toMatchObject({ ok: true });
    expect(
      await release.adapter.responses.matchActiveExact({
        absoluteUrl: release.assets[0]!.absoluteUrl,
      }),
    ).toMatchObject({ ok: true });
  });
});