https://github.com/maxdeviant/bigben

🕰️ A clock abstraction, with time travel
https://github.com/maxdeviant/bigben

Last synced: about 1 month ago
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🕰️ A clock abstraction, with time travel

• Host: GitHub
• URL: https://github.com/maxdeviant/bigben
• Owner: maxdeviant
• License: mit
• Created: 2024-04-13T00:21:27.000Z (almost 2 years ago)
• Default Branch: main
• Last Pushed: 2025-07-26T17:38:12.000Z (7 months ago)
• Last Synced: 2025-09-23T00:56:50.435Z (5 months ago)
• Language: Gleam
• Homepage:
• Size: 20.5 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

          
# bigben

[![Package Version](https://img.shields.io/hexpm/v/bigben)](https://hex.pm/packages/bigben)

[![Hex Docs](https://img.shields.io/badge/hex-docs-ffaff3)](https://hexdocs.pm/bigben/)

![Erlang-compatible](https://img.shields.io/badge/target-erlang-b83998)

![JavaScript-compatible](https://img.shields.io/badge/target-javascript-f1e05a)

🕰️ A clock abstraction, with time travel.

## Installation

```sh

gleam add bigben

```

## Usage

```gleam

import bigben/clock.{type Clock}

import bigben/fake_clock

import gleam/int

import gleam/io

import gleam/time/calendar

import gleam/time/duration

import gleam/time/timestamp

pub fn main() {

  // In your production code, you'll use the real `Clock` to get the time

  // from the system:

  let clock = clock.new()

  what_day_is_it(clock)

  // Today is July 26, 2025.

  // In test code you can construct a `FakeClock`:

  let assert Ok(now) = timestamp.parse_rfc3339("2024-04-08T02:26:31.464Z")

  let fake_clock = fake_clock.new_at(now)

  // and pass it off as a real `Clock`:

  let clock = clock.from_fake(fake_clock)

  what_day_is_it(clock)

  // Today is April 8, 2024.

  // We can then manipulate the clock to help us in our tests:

  fake_clock.advance(fake_clock, duration.hours(4 * 24))

  what_day_is_it(clock)

  // Today is April 12, 2024.

}

fn what_day_is_it(clock: Clock) {

  let #(date, _time) =

    clock |> clock.now |> timestamp.to_calendar(calendar.utc_offset)

  let month = date.month |> calendar.month_to_string

  let day = date.day |> int.to_string

  let year = date.year |> int.to_string

  io.println("Today is " <> month <> " " <> day <> ", " <> year <> ".")

}

```