JUnit Tests with Repl.it Teams for Education

Notes to myself about how to setup a Java repl to work with automatic JUnit tests.

First, add junit:junit from Packages

Next, redirect the “Run” button:

  1. Create a new .replit file and add run = "bash run.sh"

  2. Create a new shell script run.sh and add the following lines…

    javac -classpath .:/run_dir/junit-4.12.jar:/run_dir/hamcrest-core-1.3.jar:/run_dir/json-simple-1.1.1.jar -d . *.java 
    java -classpath .:/run_dir/junit-4.12.jar:/run_dir/hamcrest-core-1.3.jar:/run_dir/json-simple-1.1.1.jar ShoesTester
    # javac *.java
    # java ShoesTester

Here is a sample ShoesTester file:

import org.junit.*;
import org.junit.runner.*;
import static org.junit.Assert.*;

public class ShoesTester {
  public int add3(int n) {
    return n+3;
  public void test_add3() {

  public void trivial_test(){
    assertTrue(5 == 2+3);
    assertFalse(7 != 14/2);

  public static void main(String[] args) {
    System.out.println("Hello tests!");