Running tests from the terminal

as a manual tester

You run tests by clicking through the app.

→

in automation

CI servers have no mouse. One command — mvn test — runs your whole suite, which is exactly what Jenkins or GitHub Actions will do.

IntelliJ's green arrow is fine for development, but automation's whole point is running without a human. The terminal command you learn here is literally what CI pipelines execute in Suite 07.

The one command

terminal — from your project folder

$ mvn test

Maven then: downloads any missing dependencies → compiles your code → runs every test class → prints a summary. (If mvn isn't on your system path, use the wrapper the starter ships with: ./mvnw test on Mac/Linux, mvnw test on Windows — same thing, zero install.)

Reading the output like a pro

what success looks like

[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running HelloTest
[INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0
[INFO] BUILD SUCCESS

Two words matter: BUILD SUCCESS or BUILD FAILURE. On failure, scroll up to the first red block — a Failure means an assertion didn't match (a real test failing its check); an Error means the code broke before asserting (element not found, null pointer). Distinguishing those two is a daily automation skill: failures point at the app, errors point at your test.

Useful variations

terminal

$ mvn test -Dtest=HelloTest        # run one class only
$ mvn clean test                   # wipe old builds first (fixes weirdness)

Connect the dots: Suite 07's CI lesson is essentially "make a robot run mvn test on every commit and email you the result." You now know the exact command the robot runs.

⚠ when it breaks — the classics

'mvn' is not recognized

mvn : The term 'mvn' is not recognized as the name of a cmdlet…

Fix: Maven is bundled with IntelliJ but not on your system PATH. Use the wrapper the starter ships with — mvnw test on Windows — or run from IntelliJ's built-in terminal.

Maven runs but finds zero tests

[INFO] Tests run: 0, Failures: 0, Errors: 0, Skipped: 0

Fix: Surefire only picks up classes whose names end in Test, located under src/test/java. Check both, then re-run.

Maven complains about the Java release

[ERROR] … error: release version 21 not supported

Fix: Maven is running with an older JDK than the project targets. Check JAVA_HOME points at your JDK 21 folder, reopen the terminal, confirm with mvn -version.

⚡ exercise · run, break, and read

Run mvn test (or ./mvnw test) in your starter project. Find the Tests run / Failures line.
Break an assertion in HelloTest.java, run again, and identify the failure block in the output. Note it says Failures: 1.
Now break the code (e.g., call .length() on a String set to null), run again, and see it report an Error instead. Fix everything and get back to BUILD SUCCESS.

references

key takeaways

mvn test compiles and runs the whole suite with no IDE and no mouse.
BUILD SUCCESS / FAILURE is the headline; the first red block is the story.
Failures = assertion mismatch (suspect the app). Errors = broken test code (suspect the test).