js-10-memoize-async

[
  {
    "total": 8,
    "answer": "```js\nexport function memoizeAsync(fn, { ttlMs, now = Date.now } = {}) {\n  const cache = new Map();\n  const inFlight = new Map();\n\n  return async function(...args) {\n    const key = JSON.stringify(args);\n    const currentTime = now();\n    const entry = cache.get(key);\n\n    if (entry && currentTime - entry.timestamp < ttlMs) {\n      return entry.value;\n    }\n\n    if (inFlight.has(key)) {\n      return inFlight.get(key);\n    }\n\n    const promise = fn(...args).then(value => {\n      cache.delete(key);\n      inFlight.delete(key);\n      return value;\n    });\n\n    inFlight.set(key, promise);\n\n    return promise;\n  };\n}\n```",
    "passed": 3,
    "test_error": "(node:internal/test_runner/test:1313:7)\n    async Test.processPendingSubtests (node:internal/test_runner/test:897:7)\n  ...\n# Subtest: rejections are not cached; next call retries\nnot ok 6 - rejections are not cached; next call retries\n  ---\n  duration_ms: 0.333783\n  type: 'test'\n  location: '/tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.test.js:77:1'\n  failureType: 'testCodeFailure'\n  error: |-\n    The input did not match the regular expression /boom 2/. Input:\n    \n    'Error: boom 1'\n    \n  code: 'ERR_ASSERTION'\n  name: 'AssertionError'\n  expected:\n  actual:\n  error: 'boom 1'\n  stack: |-\n    fn (file:///tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.test.js:81:11)\n    file:///tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.js:18:21\n    file:///tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.test.js:84:30\n    waitForActual (node:assert:632:21)\n    strict.rejects (node:assert:769:31)\n    TestContext.<anonymous> (file:///tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.test.js:84:16)\n    Test.runInAsyncScope (node:async_hooks:227:14)\n    Test.run (node:internal/test_runner/test:1306:25)\n    Test.processPendingSubtests (node:internal/test_runner/test:897:18)\n    Test.postRun (node:internal/test_runner/test:1447:19)\n  operator: 'rejects'\n  stack: |-\n    async TestContext.<anonymous> (file:///tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.test.js:85:3)\n    async Test.run (node:internal/test_runner/test:1313:7)\n    async Test.processPendingSubtests (node:internal/test_runner/test:897:7)\n  ...\n# Subtest: defaults to Date.now when no clock provided\nnot ok 7 - defaults to Date.now when no clock provided\n  ---\n  duration_ms: 0.112191\n  type: 'test'\n  location: '/tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.test.js:89:1'\n  failureType: 'testCodeFailure'\n  error: |-\n    Expected values to be strictly equal:\n    \n    2 !== 1\n    \n  code: 'ERR_ASSERTION'\n  name: 'AssertionError'\n  expected: 1\n  actual: 2\n  operator: 'strictEqual'\n  stack: |-\n    TestContext.<anonymous> (file:///tmp/llmlab-js-10-memoize-async-n0re2zo1/solution.test.js:98:10)\n    async Test.run (node:internal/test_runner/test:1313:7)\n    async Test.processPendingSubtests (node:internal/test_runner/test:897:7)\n  ...\n# Subtest: expiry boundary: exactly ttl old is treated as expired\nok 8 - expiry boundary: exactly ttl old is treated as expired\n  ---\n  duration_ms: 0.08111\n  type: 'test'\n  ...\n1..8\n# tests 8\n# suites 0\n# pass 3\n# fail 5\n# cancelled 0\n# skipped 0\n# todo 0\n# duration_ms 30.795444"
  },
  {
    "total": 8,
    "answer": "```js\nexport function memoizeAsync(fn, { ttlMs, now = Date.now } = {}) {\n  const cache = new Map();\n  const inFlight = new Map();\n\n  return async function(...args) {\n    const key = JSON.stringify(args);\n    const currentTime = now();\n    const entry = cache.get(key);\n\n    if (entry && currentTime - entry.timestamp < ttlMs) {\n      return entry.value;\n    }\n\n    if (inFlight.has(key)) {\n      return inFlight.get(key);\n    }\n\n    const promise = fn(...args).then(value => {\n      cache.delete(key);\n      inFlight.delete(key);\n      return value;\n    }).catch(error => {\n      cache.delete(key);\n      inFlight.delete(key);\n      throw error;\n    });\n\n    inFlight.set(key, promise);\n\n    return promise;\n  };\n}\n```",
    "passed": 4,
    "test_error": ".\n# Subtest: different keys are cached independently\nnot ok 4 - different keys are cached independently\n  ---\n  duration_ms: 0.142671\n  type: 'test'\n  location: '/tmp/llmlab-js-10-memoize-async-_jarr3xk/solution.test.js:51:1'\n  failureType: 'testCodeFailure'\n  error: |-\n    Expected values to be strictly equal:\n    \n    3 !== 2\n    \n  code: 'ERR_ASSERTION'\n  name: 'AssertionError'\n  expected: 2\n  actual: 3\n  operator: 'strictEqual'\n  stack: |-\n    TestContext.<anonymous> (file:///tmp/llmlab-js-10-memoize-async-_jarr3xk/solution.test.js:61:10)\n    async Test.run (node:internal/test_runner/test:1313:7)\n    async Test.processPendingSubtests (node:internal/test_runner/test:897:7)\n  ...\n# Subtest: multiple arguments form the key\nnot ok 5 - multiple arguments form the key\n  ---\n  duration_ms: 0.134551\n  type: 'test'\n  location: '/tmp/llmlab-js-10-memoize-async-_jarr3xk/solution.test.js:64:1'\n  failureType: 'testCodeFailure'\n  error: |-\n    Expected values to be strictly equal:\n    \n    3 !== 2\n    \n  code: 'ERR_ASSERTION'\n  name: 'AssertionError'\n  expected: 2\n  actual: 3\n  operator: 'strictEqual'\n  stack: |-\n    TestContext.<anonymous> (file:///tmp/llmlab-js-10-memoize-async-_jarr3xk/solution.test.js:74:10)\n    async Test.run (node:internal/test_runner/test:1313:7)\n    async Test.processPendingSubtests (node:internal/test_runner/test:897:7)\n  ...\n# Subtest: rejections are not cached; next call retries\nok 6 - rejections are not cached; next call retries\n  ---\n  duration_ms: 0.290342\n  type: 'test'\n  ...\n# Subtest: defaults to Date.now when no clock provided\nnot ok 7 - defaults to Date.now when no clock provided\n  ---\n  duration_ms: 0.133591\n  type: 'test'\n  location: '/tmp/llmlab-js-10-memoize-async-_jarr3xk/solution.test.js:89:1'\n  failureType: 'testCodeFailure'\n  error: |-\n    Expected values to be strictly equal:\n    \n    2 !== 1\n    \n  code: 'ERR_ASSERTION'\n  name: 'AssertionError'\n  expected: 1\n  actual: 2\n  operator: 'strictEqual'\n  stack: |-\n    TestContext.<anonymous> (file:///tmp/llmlab-js-10-memoize-async-_jarr3xk/solution.test.js:98:10)\n    async Test.run (node:internal/test_runner/test:1313:7)\n    async Test.processPendingSubtests (node:internal/test_runner/test:897:7)\n  ...\n# Subtest: expiry boundary: exactly ttl old is treated as expired\nok 8 - expiry boundary: exactly ttl old is treated as expired\n  ---\n  duration_ms: 0.08152\n  type: 'test'\n  ...\n1..8\n# tests 8\n# suites 0\n# pass 4\n# fail 4\n# cancelled 0\n# skipped 0\n# todo 0\n# duration_ms 29.768836"
  },
  {
    "total": 8,
    "answer": "```js\nexport function memoizeAsync(fn, { ttlMs, now = Date.now } = {}) {\n  const cache = new Map();\n  const inFlight = new Map();\n\n  return async function(...args) {\n    const key = JSON.stringify(args);\n    const currentTime = now();\n    const entry = cache.get(key);\n\n    if (entry && currentTime - entry.timestamp < ttlMs) {\n      return entry.value;\n    }\n\n    if (inFlight.has(key)) {\n      return inFlight.get(key);\n    }\n\n    const promise = fn(...args).then(value => {\n      cache.delete(key);\n      inFlight.delete(key);\n      return value;\n    }).catch(error => {\n      cache.delete(key);\n      inFlight.delete(key);\n      throw error;\n    });\n\n    inFlight.set(key, promise);\n\n    return promise;\n  };\n}\n```",
    "passed": 4,
    "test_error": ""
  }
]

You are an expert programmer. Solve the task exactly as specified. Output your solution as fenced code blocks using the required file name(s) and the exact function/type signatures requested. Prefer correctness; do not include prose outside code unless asked.