[SOLVED] Cs6300 assignment 3-basic java coding and junit

This assignment assesses your basic knowledge of Java and JUnit, which you will need for future assignments and projects.
Instructions
To complete the assignment, you must complete the following tasks:
● Clone your individual GitHub repository in your local workspace. This is the same repository that you used for the previous assignment and will use for all future individual assignments:
https://github.gatech.edu/gt-omscs-se-2025summer/6300Summer25<GT username>.git
● Download the archive assignment 3.tar.gz
● Extract the archive in the root directory of the repository, which will create a directory called Assignment3 and several subdirectories. Hereafter, we will refer to the directory Assignment3 in your local repo as <dir>.
(If you do not know how to extract a “tar.gz” archive, you should be able to find plenty of resources on how to do that online–ask on Ed Discussion otherwise.)
○ Directory <dir>/src contains, in a suitable directory, the Java interface edu.gatech.seclass.MyStringInterface. It also contains an exception class edu.gatech.seclass.MyIndexOutOfBoundsException, which is used by the interface.
○ Directory <dir>/test contains, in a suitable directory, a template JUnit test class edu.gatech.seclass.MyStringTest.
○ File <dir>/lib/junit-platform-console-standalone-1.9.1.jar, a JUnit library to be used for the assignment
● Your first task is to develop a Java class called MyString that suitably implements the MyStringInterface interface that we provided. The semantics of the methods in the interface should be obvious from their name, the JavaDoc comments in the code, and the test examples in class MyStringTest–ask on Ed Discussion otherwise. Class MyString should be in the same package as the interface and should also be saved under <dir>/src/edu/gatech/seclass.
● Your second task is to develop a set of JUnit5 test cases for class MyString by completing the provided template test class MyStringTest, which contains 3 complete test cases and 13 to-be-completed test cases. For each test case in class MyStringTest whose body simply consists of the placeholder instruction “fail(“Not yet implemented”);”, you must do the following:
○ Provided for you:
■ Placeholder instruction ○ Required from you:
■ Write a meaningful test case for the method, as identified by the placeholder instruction.
■ Replace the text “<Add test description here>” in the test comment with a concise description of the purpose of the test (e.g., “Count words in an empty string”) without modifying anything else in the comment and making sure that your comment consists of a single line (i.e., does not contain newlines) and does not contain quotes or other special characters.
■ Make sure that every test method has a suitable oracle (i.e., either an assertion or an expected exception) and that the tests are not trivial (i.e., are not a copy of the provided one and have a specific purpose). In other words, each test should (1) test a specific piece of the functionality, and
(2) check that such a piece of functionality behaves as expected.
■ It should be obvious, but please also make sure that all the test cases you created pass when run against your code.
■ In addition, at least two of the tests that you develop must result in an expected exception (e.g., NullPointerException). When testing for an expected exception, make sure to assert as follows:
assertThrows(<exception_class_name>.class, () -> mystring.<method_name>(..args))

○ Consider, for example, test case testCountWordsS2():
@Test
@Timeout(value = 5000, unit = TimeUnit.MILLISECONDS)
// Description: <Add test description here> public void testCountWordsS2() { fail(“Not yet implemented”);
}

In your submission, you should have a corresponding, complete test for method countWords in class MyString, together with a concise description of the purpose of the method, such as:
@Test
@Timeout(value = 5000, unit = TimeUnit.MILLISECONDS) // Description: Count words in an empty string public void testCountWordsS2() {
<actual test, including the oracle>
}
Submission
To submit your solution, you should:
● Submit on Gradescope a file, called submission.txt that contains, in two separate lines (1) your GT username and (2) the commit ID for your submission. For example, the content of file submission.txt for George P. Burdell could look something like the following: submission.txt
gpburdell1
81b2f59

The grade you will see on Gradescope is your actual grade for the assignment, unless we find some issues with your submission (e.g., hardcoding of the results, identical tests, or similar).
Notes
● Make sure to submit only the test cases in the template and do not add extra tests. If you feel compelled to add additional tests, feel free to do so in a separate test file, which you can add to your repo but won’t be graded.
● Do not use any external library other than the provided libraries. You can obviously use all the standard JDK libraries, and you really should not need any external one.
● The only files that we will use to grade your submissions are:
○ Assignment3/src/edu/gatech/seclass/MyString.java
○ Assignment3/test/edu/gatech/seclass/MyStringTest.java
○ Assignment3/lib/junit-platform-console-standalone-1.9.1.jar
Feel free to commit extra files (e.g., IDEA’s project-related files), as this does not make a difference for your grade.
● You cannot modify any of the following:
○ The provided interface (MyStringInterface)
○ The already provided test cases except for those that you are supposed to implement, obviously, whose body is simply “fail(“Not yet implemented”)”.
● You should use Java version 17 to solve the assignment.
● Before submitting, make sure to compile and run your test cases as a collective suite (not only individually) and to check that they all pass. Although gradescope performs the same checks, it is much faster to do that locally, on your machine, beforehand.
● Verify that your final commit ID contains what you intend, and is pushed to the repository, by cloning it in a separate location or viewing it on github.gatech.edu.
● More specifically, you can check that you committed and pushed all the files you needed by doing the following:
○ Clone a fresh copy of your personal repo in another directory
○ Go to directory Assignment3 in this fresh clone
○ Compile your code. One way to do is to run, from a Unix-like shell:
javac -cp lib/* -d classes src/edu/gatech/seclass/* test/edu/gatech/seclass/MyStringTest.java
○ Run your tests. Again, from a Unix-like shell, you can run:
java -cp classes:lib/* org.junit.platform.console.ConsoleLauncher
–select-class edu.gatech.seclass.MyStringTest
● You can perform multiple commits as you produce your solution. This is not only fine, but actually very much encouraged.
● We also encourage you to use a “development” branch and merge your stable version(s) into the “main” branch. If interested, see this site for an example of a possible branching model of this kind. (There are many others.)
● From this point on in the course, you should NOT run the git repository reset commands given in Assignment 2, any version of force –push, or any commands deleting branches, tags, or prior commits on your repository, as these commands could cause you to lose prior work.

Gradescope Feedback/Requests for Clarifications
Requests for clarifications: If you need clarifications on a specific test or Gradescope output, please post privately on Ed Discussion (we will make it public if appropriate) and make sure to add, when it applies:
● a link to the Gradescope results,
● an inlined, complete copy of the test(s) you reference, if yours (i.e., no screenshots or commit IDs, please), and
The bottom line is that, to make the interaction efficient, you should make your posts as self-contained and easy-to-check as possible. The faster we can respond to the posts, the more students we can help.
Using Intellij IDEA
Although it is not mandatory, we recommend that you use IntelliJ IDEA to complete the assignment, so that you can also get familiar with this IDE (if you aren’t already). To do so, you should open IDEA and do the following (notice the initial, alternative steps):
● If you are in the initial IntelliJ IDEA screen (see image below), do the following:

○ Click “Open”
○ Select <dir> as the directory to import

● Otherwise, if you are already in a project window, do the following
○ Click menu “File” => “New” => “Project from Existing Sources…

○ Select <dir> as the project directory

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○ Select “Create project from existing sources”

○ Click “Next” accepting the default choices (make sure to include the provided libraries and to select Java SDK 17) and then “Finish”:
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○ If SDK is not installed, choose to download:

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