dtonhofer
Functional Programming in Java, Second Edition: Functional Programming in Java, Second Edition: JUnit code improvements for Chapter 11, pages 184 ff “Refactoring More Complex loops”
The same remarks apply as for “Refactoring the Traditional for Loop”
- No
init() - Classes under test implement a common interface that is called in tests.
- Negative tests which apply for input less than 1900, resulting in exceptions.
package chapter11;
import org.junit.jupiter.api.Test;
import java.time.Year;
import java.util.stream.IntStream;
import static org.junit.jupiter.api.Assertions.*;
// Everything is inside the MoreComplexLoopTest class for convenience.
// Documentation for java.time.Year.isLeap()
// https://docs.oracle.com/javase/8/docs/api/java/time/Year.html#isLeap--
public class MoreComplexLoopTest {
interface LeapYears {
int countFrom1900(int upTo);
}
static class LeapYearCountBefore implements LeapYears {
public int countFrom1900(int upTo) {
if (upTo < 1900) {
throw new IllegalArgumentException("The passed value is < 1900: " + upTo);
}
int count = 0;
for (int year = 1900; year <= upTo; year += 4) {
if (Year.isLeap(year)) {
count++;
}
}
return count;
}
}
static class LeapYearCountAfter implements LeapYears {
public int countFrom1900(int upTo) {
if (upTo < 1900) {
throw new IllegalArgumentException("The passed value is < 1900: " + upTo);
}
return (int) IntStream.iterate(1900, year -> year <= upTo, year -> year + 4)
.filter(Year::isLeap)
.count();
}
}
private static void commonLeapYearsTests(final LeapYears leapYears) {
assertAll(
() -> assertEquals(0, leapYears.countFrom1900(1900)),
() -> assertEquals(25, leapYears.countFrom1900(2000)),
() -> assertEquals(27, leapYears.countFrom1900(2010)),
() -> assertEquals(31, leapYears.countFrom1900(2025)),
() -> assertEquals(49, leapYears.countFrom1900(2100)),
() -> assertEquals(267, leapYears.countFrom1900(3000)),
() -> assertThrows(IllegalArgumentException.class, () -> leapYears.countFrom1900(1800))
);
}
@Test
void leapYearCountBefore() {
commonLeapYearsTests(new LeapYearCountBefore());
}
@Test
void leapYearCountAfter() {
commonLeapYearsTests(new LeapYearCountAfter());
}
}
Popular Pragmatic Bookshelf topics
Many tasks_proj/tests directories exist in chapters 2, 3, 5 that have tests that use the custom markers smoke and get, which are not decl...
New
When I try the command to create a pair of migration files I get an error.
user=> (create-migration "guestbook")
Execution error (Ill...
New
Title: Hands-on Rust: question about get_component (page 295)
(feel free to respond. “You dug you’re own hole… good luck”)
I have somet...
New
I’m new to Rust and am using this book to learn more as well as to feed my interest in game dev. I’ve just finished the flappy dragon exa...
New
Running mix deps.get in the sensor_hub directory fails with the following error:
** (Mix) No SSH public keys found in ~/.ssh. An ssh aut...
New
Hi, I have just acquired Michael Fazio’s “Kotlin and Android Development” to learn about game programming for Android. I have a game in p...
New
When trying to run tox in parallel as explained on page 151, I got the following error:
tox: error: argument -p/–parallel: expected one...
New
I am using Android Studio Chipmunk | 2021.2.1 Patch 2
Build #AI-212.5712.43.2112.8815526, built on July 10, 2022
Runtime version: 11.0....
New
@mfazio23
I’ve applied the changes from Chapter 5 of the book and everything builds correctly and runs. But, when I try to start a game,...
New
Hello faithful readers! If you have tried to follow along in the book, you are asked to start up the dev environment via dx/build and ar...
New
Other popular topics
Hello Devtalk World!
Please let us know a little about who you are and where you’re from :nerd_face:
New
If it’s a mechanical keyboard, which switches do you have?
Would you recommend it? Why?
What will your next keyboard be?
Pics always w...
New
Brace yourself for a fun challenge: build a photorealistic 3D renderer from scratch! In just a couple of weeks, build a ray tracer that r...
New
Ruby, Io, Prolog, Scala, Erlang, Clojure, Haskell. With Seven Languages in Seven Weeks, by Bruce A. Tate, you’ll go beyond the syntax—and...
New
I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
New
No chair. I have a standing desk.
This post was split into a dedicated thread from our thread about chairs :slight_smile:
New
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
Hello,
I’m a beginner in Android development and I’m facing an issue with my project setup. In my build.gradle.kts file, I have the foll...
New
Fight complexity and reclaim the original spirit of agility by learning to simplify how you develop software. The result: a more humane a...
New
Use advanced functional programming principles, practical Domain-Driven Design techniques, and production-ready Elixir code to build scal...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /java
- /clojure
- /emacs
- /haskell
- /typescript
- /svelte
- /onivim
- /kotlin
- /c-plus-plus
- /crystal
- /react
- /tailwind
- /gleam
- /ocaml
- /elm
- /vscode
- /flutter
- /html
- /ash
- /deepseek
- /zig
- /opensuse
- /centos
- /php
- /scala
- /react-native
- /lisp
- /sublime-text
- /textmate
- /debian
- /nixos
- /agda
- /deno
- /django
- /kubuntu
- /arch-linux
- /nodejs
- /spring
- /ubuntu
- /revery
- /manjaro
- /julia
- /lua
- /diversity
- /quarkus
- /markdown









