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
Title: Web Development with Clojure, Third Edition - migrations/create not working: p159
When I execute the command:
user=> (create-...
New
Hi @venkats,
It has been mentioned in the description of ‘Supervisory Job’ title that 2 things as mentioned below result in the same eff...
New
The generated iex result below should list products instead of product for the metadata. (page 67)
iex> product = %Product{}
%Pento....
New
@noelrappin
Running the webpack dev server, I receive the following warning:
ERROR in tsconfig.json
TS18003: No inputs were found in c...
New
“The ProductLive.Index template calls a helper function, live_component/3, that in turn calls on the modal component. ”
Excerpt From: Br...
New
The markup used to display the uploaded image results in a Phoenix.LiveView.HTMLTokenizer.ParseError error.
lib/pento_web/live/product_l...
New
I’m a newbie to Rails 7 and have hit an issue with the bin/Dev script mentioned on pages 112-113.
Iteration A1 - Seeing the list of prod...
New
Skimming ahead, much of the following is explained in Chapter 3, but new readers (like me!) will hit a roadblock in Chapter 2 with their ...
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
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
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 have a thread about the keyboards we have, but what about nice keyboards we come across that we want? If you have seen any that look n...
New
Do the test and post your score :nerd_face:
:keyboard:
If possible, please add info such as the keyboard you’re using, the layout (Qw...
New
Small essay with thoughts on macOS vs. Linux:
I know @Exadra37 is just waiting around the corner to scream at me “I TOLD YOU SO!!!” but I...
New
Oh just spent so much time on this to discover now that RancherOS is in end of life but Rancher is refusing to mark the Github repo as su...
New
Use WebRTC to build web applications that stream media and data in real time directly from one user to another, all in the browser.
...
New
Author Spotlight
Jamis Buck
@jamis
This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
Inside our android webview app, we are trying to paste the copied content from another app eg (notes) using navigator.clipboard.readtext ...
New
Background
Lately I am in a quest to find a good quality TTS ai generation tool to run locally in order to create audio for some videos I...
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
- /elm
- /flutter
- /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
- /spring
- /manjaro
- /diversity
- /lua
- /julia
- /markdown
- /c








