I'm building this assignment to help people get started with writing tests and TDD. I've so far managed to write two basic chapters that involve date calculations. Date calculations are usually error prone because Maths is hard and dates are harder. Writing tests will give us confidence.

Chapters

1. Validate date of birth

For a hypothetical user profile screen, the user’s date of birth needs to validated.

• The date’s pattern should be d/MM/yyyy. E.g., 11/04/1992.
• The date should not be in the future.

The unit tests for this can be found in DateOfBirthValidatorTest. The tests are named to match the business spec, but they’re empty. Your mission, should you choose to accept it, is to complete them with expected results and make them pass.

2. Calculate relative timestamp

Given a date, generate relative timestamps that will be displayed on the UI. Assume that the dates will only be in the past for simplicity.

• If the date is of today, generate Today.
• If the date is of yesterday, generate Yesterday.
• If the date is within the current month, generate {days} ago. E.g., 24 days ago.
• For dates older than that, print {date} {month}, {year}. E.g., 5 Jun 2018, 21 Oct 2017, etc.

These strings must be accessed through strings.xml keeping localization in mind. Because accessing them requires Android's context, tests for this chapter will run as Android tests and are present in RelativeTimestampGeneratorAndroidTest.

Useful information

Running tests from terminal

Although I recommend running the tests from Studio because the results are nicer too look at, but just in case:

Unit tests:

./gradlew testDebug

Android tests:

./gradlew connectedDebugAndroidTest

ThreeTenABP

This assignment uses lazythreetenbp for working with date and time. Due to some limitations in IntelliJ, the IDE doesn't know how to find and download its sources. As a work around, the sources are included with this project as a JAR inside libraries package that can be manually attached to Android Studio.

License

This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

Full license can be read here: https://raw.githubusercontent.com/saket/TestAssignment/master/LICENSE