Home Challenges Reps Problems Leaderboard Take a challenge

Five tests, one behaviour

Copy-pasted [Fact]s with one number changed. Collapse them into a [Theory].

Beginner12 min on the clock5 graded checks · 100 pointsTesting an ASP.NET Core API

Graded by reading your code against the checklist below.

What you build

Replace the five [Fact] methods with one [Theory]
Give it an [InlineData] row per case, including the expected result
Take the age and the expected value as method parameters
Keep every boundary the original covered — 17, 18, 65 and 66
Leave no [Fact] copies behind

Done means

One [Theory] with at least five [InlineData] rows covering both boundaries, and no [Fact] left.

How it is graded

Published in full, before you start — every point is one of these and there is nothing else.

One [Theory] replaces the copies+20One test, many cases
Each case is an [InlineData] row+20One test, many cases
The method takes the row values as parameters+20One test, many cases
Every boundary the copies covered survives+25Off by one
The copy-pasted [Fact] methods are gone+15One test, many cases

What it teaches

One test, many casesbeginner

Five near-identical tests with one number changed are one test with five rows — and the version with rows is where the sixth boundary costs a line instead of a method.

Off by onebeginner

For any range, three values per edge — one below, the edge itself, one above — catch every single-character mistake it is possible to make in the comparison.

The rest of Testing an ASP.NET Core API

Your first xUnit testBeginner · 12 min Stop calling the real thingIntermediate · 18 min The whole pipeline, in memoryIntermediate · 20 min The paths nobody testsIntermediate · 18 min The suite that only fails on CIAdvanced · 22 min