JUnit VS Eclipse Collections

Because I only wanna use the cmd java test, so I chose Junit4 which supports Plain-old JAR. I did test according to the Getting started document. But when I ran the javac -cp .:junit-4.XX.jar:hamcrest-core-1.3.jar CalculatorTest.java I got the error message CalculatorTest.java:4: error: package main does not exits. I tried to reorganize the folder and set Path according to others' experience 1, 2, but it still did not work.

Oops, another error. This is why we should read the manual 😅.

JUnit4

Delete those imports and remove the junit-jupiter-api dependency. Follow the instructions for JUnit 4.

Quite a lot of Java dependencies bring Junit 4 or Junit vintage engine as a transitive dependency.

The AHTest039.json file is the actual test. My testRunner() method (no relation to JUnit test runners) reads that JSON file, processes it, and asserts that the test passed. So my test class consists of a few Java methods, and what is essentially a list of JSON files to process.

eclipse-collections for Java.

Each year when I do the Advent of Code challenge I use it as an opportunity to learn a new language or tool chain. This year I am writing in Java 17 (I have not used Java since Java 8), along with Eclipse Collections, and using VS Code as my IDE.

If you want design like that, you can just use Eclipse Collections (https://www.eclipse.org/collections/). But do note that that design has its own problems if you are after perfection.

Eclipse-Collections

You were a little wrong, surely you can see that? And for Collections that don't autobox, you want to use something like https://github.com/eclipse/eclipse-collections