@glucoseiq/testing

Fixed-seed CGM-shaped fixtures for tests, examples, and local demos. Requires Node >=24.

Install

npm install @glucoseiq/testing

First use

import { generateCGMSeries, scenarios } from '@glucoseiq/testing'

const readings = generateCGMSeries({ days: 14, seed: 7 })
const traceWithGap = scenarios.gappyTrace()

console.log(readings.length, traceWithGap.length)

Options and defaults

generateCGMSeries accepts these options:

| Option | Default | Meaning | | --- | --- | --- | | days | 1 | Number of days. | | intervalMin | 5 | Minutes between readings. | | seed | 42 | Safe integer used to repeat the same generated series. | | start | 2024-01-01T00:00:00Z | ISO timestamp for the first day. | | basal | 110 | Baseline in mg/dL. | | mealTimes | 420, 780, 1140 | Meal times as minutes of day. | | mealAmplitude | 70 | Nominal meal excursion amplitude in mg/dL. | | noise | 8 | Maximum correlated sensor variation in mg/dL. | | nocturnalHypoDays | [] | Zero-based days receiving a smooth 02:00–04:00 dip. | | unit | mg/dL | Output unit, either mg/dL or mmol/L. |

The seed gives each meal its own timing offset (-15 to +25 minutes), peak amplitude (65% to 125% of mealAmplitude), 40- to 90-minute rise, and 120- to 210-minute recovery. Meal responses ease in and out instead of changing direction sharply. Sensor variation is bounded and carries across neighboring readings, while requested nocturnal lows form a smooth two-hour depression.

The steadyDay, hypoNight, rollercoaster, and gappyTrace scenarios use fixed settings and seeds.

Invalid input

Invalid input throws RangeError. The generator validates option shape, numeric bounds, the start timestamp, units, meal-time arrays, and requested output size before allocating the result.

Safety limits

One call is capped at 100,000 readings and 100,000 seeded meal responses. The output is synthetic CGM-shaped data and is not clinically representative or a substitute for validation with real device data. Do not use generated values for medical decisions.

Documentation

• Testing guide
• Public API
• Changelog
• MIT license