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
Running the examples in chapter 5 c under pytest 5.4.1 causes an AttributeError: ‘module’ object has no attribute ‘config’.
In particula...
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 ran this command after installing the sample application:
$ cards add do something --owner Brian
And got a file not found error:
Fil...
New
I’m under the impression that when the reader gets to page 136 (“View Data with the Database Inspector”), the code SHOULD be able to buil...
New
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
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
When running the program in chapter 8, “Implementing Combat”, the printout Health before attack was never printed so I assumed something ...
New
I just bought this book to learn about Android development, and I’m already running into a major issue in Ch. 1, p. 20: “Update activity...
New
@mfazio23
Android Studio will not accept anything I do when trying to use the Transformations class, as described on pp. 140-141. Googl...
New
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
New
Other popular topics
Bought the Moonlander mechanical keyboard. Cherry Brown MX switches. Arms and wrists have been hurting enough that it’s time I did someth...
New
Tailwind CSS is an exciting new CSS framework that allows you to design your site by composing simple utility classes to create complex e...
New
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
In case anyone else is wondering why Ruby 3 doesn’t show when you do asdf list-all ruby :man_facepalming: do this first:
asdf plugin-upd...
New
The V Programming Language
Simple language for building maintainable programs
V is already mentioned couple of times in the forum, but I...
New
A few weeks ago I started using Warp a terminal written in rust. Though in it’s current state of development there are a few caveats (tab...
New
New
Author Spotlight:
VM Brasseur
@vmbrasseur
We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...
New
There appears to have been an update that has changed the terminology for what has previously been known as the Taskbar Overflow - this h...
New
This is a very quick guide, you just need to:
Download LM Studio: https://lmstudio.ai/
Click on search
Type DeepSeek, then select the o...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /emacs
- /java
- /haskell
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /flutter
- /elm
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /centos
- /deepseek
- /php
- /scala
- /react-native
- /lisp
- /textmate
- /sublime-text
- /nixos
- /debian
- /agda
- /django
- /deno
- /kubuntu
- /arch-linux
- /nodejs
- /revery
- /ubuntu
- /manjaro
- /spring
- /diversity
- /lua
- /julia
- /markdown
- /c








