[Solved] CS1632 Supplement1

In this exercise, we will test the Rent-A-Cat rental system software once more,but this time with BDD. Please review the Lecture 10 Supplement: BDD slidesif you havent already.

We will use the Gherkin language to specify behaviors for Rent-A-Cat and usethe Cucumber framework to test those behaviors.

# Prerequisites

I recommend that you do this on the Eclipse IDE since it is the easiest.

Please install the Cucumber plug-in for Eclipse following these steps (recommended):1. Click on Help > Eclipse Marketplace.2. Type cucumber in the Find search box and press Enter.3. Install the Cucumber Eclipse Plugin that pops up in the search box.4. You will be asked to restart Eclipse to complete installation. Please do so.

Otherwise, you should be able to use the command line Maven tool to install theCucumber plug-in. But for that, you will need to install Maven first using thefollowing link (not recommended): https://maven.apache.org/download.cgi

## Running Cucumber Tests

To use the Eclipse Cucumber plog-in, first open the Eclipse project I have made for you:1. Click on File > Open Projects from File System.2. Click on Directory and browse to the folder with CS1632_Fal2020/exercises/Supplement1.3. The Supplement1 folder imported as Eclipse project checkbox should be auto-selected.4. Click on the Finish button.

Then, run the Maven test goal:1. Right click on the project root RentACat-Cucumber.2. Click on Run as in the context menu.3. Select Maven test.4. Then the test results should be visible in the bottom Console window.

If you dont want to keep doing the above when running Cucumber tests, you can create a Run Configuration.1. Click on Run > Run Configurations.2. Select Maven Build in the list of run types at the left.3. Click on the New launch configuration icon at the far left of the toolbar.4. Edit the Name: box to something like RentACat Cucumber Test5. Edit the Base directory box by clickig on the Workspace button and selecting the RentACat-Cucumber project.6. Edit the Goals: box by inputing test7. Click on the Apply button.

Now if you click on the little arrow beside the Run button on the toolbar thatlooks like a play icon, you should see your newly made run configuration.

If you are not using Eclipse and you wish to run the tests from the command line, use the command line Maven tool:1. cd into the CS1632_Fal2020/exercises/Supplement1 directory.2. Invoke mvn test:`> mvn test`

## Expected Outcome

Initially when you run the Cucumber tests, all your tests will fail, partlybecause RentACatImpl is incomplete and partly because your Cucumber testingcode is incomplete. You will get a long list of failures followed by this summary text:

`Tests run: 14, Failures: 9, Errors: 1, Skipped: 0

[INFO] [INFO] BUILD FAILURE[INFO] [INFO] Total time: 4.659 s[INFO] Finished at: 2020-09-20T22:08:14-04:00[INFO] [ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.12.4:test (default-test) on project RentACat-Cucumber: There are test failures.`

The above tells you that out of 14 tests, 9 tests failed, and there was anerror in one test. An error happens when a test is incomplete or is otherwisemalformed. In order to get the details about the failures and errors, you canread the messages that precede the summary output, or you can also read theCucumber report which is much nicer. Somewhere above that summary is going tobe a link to a report in red font that looks like this:

`????????????????????????????????????????????????????????????????????????????? View your Cucumber Report at: ?? https://reports.cucumber.io/reports/0334222f-8b03-4075-80ba-a63d2c887c90 ?? ?? This report will self-destruct in 24h unless it is claimed or deleted. ?????????????????????????????????????????????????????????????????????????????`

Copy and paste that link on a web browser and you should see a report thatlooks like the following:

<img alt=Cucumber Report src=img/cucumber_report.png width=700>

The green check marks indicate steps that have passed. The red cross marksindicate steps that have failed. The blue square marks indicate steps thatwere skipped because a previous step failed. The yellow question marksindicate steps that were erroneous (e.g. matching Cucumber step does not existfor that step). For the failed steps, a Java stack trace is attached so thatyou can track down the failure.

## What To Do

You will modify three files: **RentACatImpl.java**, **StepDefinitions.java**,and **rent_a_cat_return_cats.feature**. The RentACatImpl class is the(incomplete) implementation of the Rent-A-Cat system. The StepDefinitionsclass is the (incomplete) implementation of Cucumber steps corresponding to theGherkin steps. The rent_a_cat_return_cats.feature file is a description of thereturn cat feature in the Rent-A-Cat system written in the Gherkin language.All the places to modify have been marked by // TODO comments.

### Updating RentACatImpl.java

Lets first start by completing src/main/java/RentACatImpl.java. You can justcopy the version that you completed for Exercise 2. Just by doing that, manytests will pass now. Try running it after copying the file and you will get:

`Tests run: 14, Failures: 5, Errors: 1, Skipped: 0`

Now we only have 5 failures and 1 errors. All the tests in Feature: Rent-A-Catlisting (in thesrc/test/resources/edu/pitt/cs/cs1632/rent_a_cat_list_cats.feature file) pass.Most of the failures are from Feature: Rent-A-Cat renting.

### Adding Steps in StepDefinitions.java for the rent cats Feature

Lets look at thesrc/test/resources/edu/pitt/cs/cs1632/rent_a_cat_rent_cats.feature file to seewhat the problem is. Well, the Gherkin feature description makes logicalsense. So it must be the Cucumber steps that implement the Gherkin steps thatmust be the problem. All the Cucumber steps are inside thesrc/test/java/edu/pitt/cs/cs1632/StepDefinitions.java file. In that file, youcan see all corresponding methods for each Gherkin step. Some of the methodshave the // TODO: Implement comment and the default action is to fail(). Thefailing methods are the ones used for the renting feature in Gherkin. Replacefail() with the proper implementation of each method. Observe how other stepswere implemented to get hints. After this, if you run Cucumber again, you willget:

`Tests run: 14, Failures: 0, Errors: 1, Skipped: 0`

### Further Modifying StepDefinitions.java and User Story for the rent cats Feature

So where did this error come from? If you scroll up in the Cucumber output alittle bit, you will see the following messages:

`Attempt to return a cat that does not exist(Rent-A-Cat returning) Time elapsed: 0.07 sec <<< ERROR!io.cucumber.junit.UndefinedStepException: The step I return cat number 4 is undefined. You can implement it using the snippet(s) below:

@When(I return cat number {int})public void iReturnCatNumber(Integer int1) {// Write code here that turns the phrase above into concrete actionsthrow new io.cucumber.java.PendingException();}

Some other steps were also undefined:

@Then(the return is unsuccessful)public void theReturnIsUnsuccessful() {// Write code here that turns the phrase above into concrete actionsthrow new io.cucumber.java.PendingException();}`

Cucumber is telling you that there is no corresponding Cucumber step for theGherkin step I return cat number 4. And then, it is kind enough to even givea code snippet you can use to start implementing that step! Of course, youwill have to replace throw new io.cucumber.java.PendingException(); with codeto actually implement that step. Cucumber also tells you some additional stepsthat were undefined as a courtesy.

Once you implement those steps, you may suffer a NullPointerException due tothe r reference being null. Now why would that happen all of a sudden?Hint: compare rent_a_cat_return_cats.feature where the error happened to therent_a_cat_rent_cats.feature, focusing on the Background: section. Once youfix that, you should finally get the following:

`Tests run: 14, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 2.983 sec`

Congratulations! If you have time, try to complete the other 4 scenarios inrent_a_cat_return_cats.feature and see if you can have them pass too!

## Submission

Each pairwise group will submit the exercise *once* to GradeScope, by *onemember* of the group. The submitting member will press the View or editgroup link at the top-right corner of the assignment page after submission toadd his/her partner. That way, the feedback will be accessible to both of you.I recommend that you divide the list of methods to implement / test into twohalves and working on one half each.

You will create a github repository just for Supplementary Exercise 1. Addyour partner as a collaborator so both of you have access. Make sure you keepthe repository *PRIVATE* so that nobody else can access your repository. Thisapplies to all future submissions for this course. Once you are done modifyingcode, dont forget to commit and push your changes to the github repository.When you are done, submit your github repository to GradeScope at theSupplementary Exercise 1 GitHub link. Once you submit, GradeScope will runthe autograder to grade you. If you get deductions, fix your code based on thefeedback and resubmit. Repeat until you dont get deductions.

IMPORTANT: Please keep the github private!

## GradeScope Feedback

The feedback you get from the GradeScope autograder is based on the Cucumbersummary output. For example, if you get the following output:

`Tests run: 14, Failures: 9, Errors: 1, Skipped: 0`

There were 9 failures and 1 errors so the final score is: 14 9 1 = 4.

## Resources

* Gherkin Syntax Reference:https://cucumber.io/docs/gherkin/reference/

* Tutorial on how to write Cucumber steps:https://cucumber.io/docs/cucumber/step-definitions/

* Cucumber API reference:https://cucumber.io/docs/cucumber/api/

* Introduction to Behavior Driven Development (BDD):https://cucumber.io/docs/bdd/