cs100-F2019-practical3-starter

Table of Contents

• Table of Contents
• Introduction
• Continuous Learning
• System Commands
  • Using Docker
  • Using Gradle
• Expected Program Output
• Automated Checks with GatorGrader
• Downloading Project Updates
• Using Travis CI
• System Requirements
• Reporting Problems
• Receiving Assistance
• Project Assessment

Introduction

Designed for use with GitHub Classroom and GatorGrader, this repository contains the starter for a practical assignment in an introductory computer science class that uses the Java programming language. The Travis CI builds for this repository will pass, as evidenced by a green ✔ instead of a red ✗ appearing in the commit logs. Please bear in mind that much of the content in this document is written in its current form under the assumption that it will accompany the "starter" repository that an instructor shares with a student through the use of GitHub Classroom.

This assignment requires a programmer to fix the defects in a Java program, called ComputeMoonDistance, that incorrectly performs computations with variables. The first line of output will contain the name of the programmer and the date at which the program was run. The next three lines should feature the output of computed values. As verified by Checkstyle, the source code for the ComputeMoonDistance.java file must adhere to all of the requirements in the Google Java Style Guide.

The source code in the ComputeMoonDistance.java file must also pass additional tests set by the GatorGrader tool. For instance, GatorGrader will check to ensure that ComputeMoonDistance produces the correct number of lines of output and that you use the new Date() construct in the Java code. GatorGrader will also check that your program performs the correct computation and produces the expected output for the number of yards to the moon. Please note that the provided version of ComputeMoonDistance.java will not compile correctly because it does not follow all of the syntax rules of the Java programming language. It is also important to point out that the program is also semantically incorrect and thus it will not, by default, perform the correct computation.

A carefully formatted assignment sheet for this project provides more details about the steps that a computer scientist should take to complete this assignment. You can view this assignment sheet by visiting the listing of laboratories on the course web site created by the course instructor. Please pay attention to the icons in the left-hand margin of the assignment sheet as they will help you to understand and remember what steps you should take at key parts of the assignment.

Continuous Learning

If you have not done so already, please read all of the relevant GitHub Guides that explain how to use many of the features that GitHub provides. In particular, please make sure that you have read the following GitHub guides: Mastering Markdown, Hello World, and Documenting Your Projects on GitHub. Each of these guides will help you to understand how to use both GitHub and GitHub Classroom.

Students who want to learn more about how to use Docker should review the Docker Documentation. Students are also encouraged to review the documentation for their text editor, which is available for text editors like Atom and VS Code. You should also review the Git documentation to learn more about how to use the Git command-line client. In addition to talking with the instructor and technical leader for your course, students are encouraged to search StackOverflow for answers to their technical questions.

To do well on this assignment, you should also read Chapters 1 and 2 in the course textbook, ensuring that you fully understand all of the details that we have discussed in class and investigated during a practical or laboratory session. Please see the course instructor or one of the student technical leaders if you have questions about any of these reading assignments.

System Commands

This project invites students to enter system commands into a terminal window. This assignment uses Docker to deliver programs, such as gradle and the source code and packages needed to run GatorGrader, to a students' computer, thereby eliminating the need for a programmer to install them on their development workstation. Individuals who do not want to install Docker can optionally install of the programs mentioned in the Project Requirements section of this document.

Using Docker

Once you have installed Docker Desktop, you can use the following docker run command to start gradle grade as a containerized application, using the DockaGator Docker image available on DockerHub.

docker run --rm --name dockagator \
  -v "$(pwd)":/project \
  -v "$HOME/.dockagator":/root/.local/share \
  gatoreducator/dockagator

The aforementioned command will use "$(pwd)" (i.e., the current directory) as the project directory and "$HOME/.dockagator" as the cached GatorGrader directory. Please note that both of these directories must exist, although only the project directory must contain something. Generally, the project directory should contain the source code and technical writing of this assignment, as provided to a student through GitHub. Additionally, the cache directory should not contain anything other than directories and programs created by DockaGator, thus ensuring that they are not otherwise overwritten during the completion of the assignment. To ensure that the previous command will work correctly, you should create the cache directory by running the command mkdir $HOME/.dockagator. If the above docker run command does not work correctly on the Windows operating system, you may need to instead run the following command to work around limitations in the terminal window:

docker run --rm --name dockagator \
  -v "$(pwd):/project" \
  -v "$HOME/.dockagator:/root/.local/share" \
  gatoreducator/dockagator

If that Docker command does not work correctly, then you should first consider writing the command on a single line in your terminal window and then replacing $(pwd) and $HOME with the fully qualified name of the directory that those variables represent. Students who are stuck on this step should explain to the course instructor what they have already tried and what challenges they currently face.

Here are some additional commands that you may need to run when using Docker:

• docker info: display information about how Docker runs on your workstation
• docker images: show the Docker images installed on your workstation
• docker container list: list the active images running on your workstation
• docker system prune: remove many types of "dangling" components from your workstation
• docker image prune: remove all "dangling" docker images from your workstation
• docker container prune: remove all stopped docker containers from your workstation
• docker rmi $(docker images -q) --force: remove all docker images from your workstation

Using Gradle

Since the above docker run command uses a Docker images that, by default, runs gradle grade and then exits the Docker container, you may want to instead run the following command so that you enter an "interactive terminal" that will allow you to repeatedly run commands within the Docker container.

docker run -it --rm --name dockagator \
  -v "$(pwd)":/project \
  -v "$HOME/.dockagator":/root/.local/share \
  gatoreducator/dockagator /bin/bash

Once you have typed this command, you can use the GatorGrader tool in the Docker container by typing the command gradle grade in your terminal. Running this command will produce a lot of output that you should carefully inspect. If GatorGrader's output shows that there are no mistakes in the assignment, then your source code and writing are passing all of the automated baseline checks. However, if the output indicates that there are mistakes, then you will need to understand what they are and then try to fix them.

You can also complete several important Java programming tasks by using the gradle tool. For instance, you can compile (i.e., create bytecode from the program's source code if it is correct) the program using the command gradle build. Here are some other commands that you can type:

• gradle grade: run the GatorGrader tool to check your work
• gradle clean: clean the project of all the derived files
• gradle check: check the quality of the code using Checkstyle
• gradle build: create the bytecode from the Java source code
• gradle run: run the Java program in the command-line
• gradle tasks: display details about the Gradle system

To run one of these commands, you must be in the main (i.e., "home base") directory for this assignment where the build.gradle file is located.

Expected Program Output

Typing the command gradle run in the terminal window should produce the following output for the completed version of DisplayOutput. As long as your program adheres to all of the requirements for the assignment and passes all of the verification checks, your version should produce similar output. With that said, program output may vary according to, for instance, the name of the programmer and the date on which you ran the program.

> Configure project :
Configured GatorGradle 0.4.4

> Task :run
Gregory M. Kapfhammer Tue Sep 17 10:14:21 EDT 2019
Distance to the moon in miles: 238855
Number of miles in a yard: 1760
Number of yards to the moon is: 420384800

BUILD SUCCESSFUL in 891ms
2 actionable tasks: 1 executed, 1 up-to-date

Running the command gradle -q --console plain run will suppress the display of Gradle's diagnostic information and produce output like the following.

Gregory M. Kapfhammer Tue Sep 17 10:14:56 EDT 2019
Distance to the moon in miles: 238855
Number of miles in a yard: 1760
Number of yards to the moon is: 420384800

Automated Checks with GatorGrader

In addition to meeting all of the requirements outlined in the assignment sheet, your submission must pass the following checks that GatorGrader automatically assesses:

• Repository has at least 5 commit(s)
• The ComputeMoonDistance.java in src/main/java/practicalthree has at least 2 multiple-line Java comment(s)
• The ComputeMoonDistance.java in src/main/java/practicalthree has at least 2 single-line Java comment(s)
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 0 of the Add Your Name Here fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 0 of the TODO fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 1 of the String[] args fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 1 of the import java.util.Date fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 1 of the milesToMoon * yardsPerMile fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 1 of the new Date() fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 1 of the package practicalthree; fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 1 of the public class ComputeMoonDistance fragment
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 3 match(es) of the int (\\w)+ regular expression
• The ComputeMoonDistance.java in src/main/java/practicalthree has exactly 4 of the println( fragment
• The command gradle -q --console plain run executes correctly
• The command gradle build executes correctly
• The command output has exactly 1 of the 1760 fragment
• The command output has exactly 1 of the 238855 fragment
• The command output has exactly 1 of the 420384800 fragment
• The command output has exactly 4 lines
• The file ComputeMoonDistance.java exists in the src/main/java/practicalthree directory

If GatorGrader's automated checks pass correctly, the tool will produce the output like the following in addition to returning a zero exit code (which you can access by typing the command echo $?).

        ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
        ┃ Passed 20/20 (100%) of checks for cs100-F2019-practical3! ┃
        ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

Downloading Project Updates

If the course instructor pushes updates to this assignment and you received it through GitHub Classroom and you would like to also receive these updates, then you can type this command in the main directory for this assignment:

git remote add download [email protected]:Allegheny-Computer-Science-100-F2019/cs100-F2019-practical3-starter.git

You should only need to type this command once; running the command additional times may yield an error message but will not negatively influence the state of your Git repository. Now, you are ready to download the updates provided by the GatorGrader maintainers by typing this command:

git pull download master

This second command can be run whenever the maintainers needs to provide you with new source code for this assignment. However, please note that, if you have edited the files that we updated, running the previous command may lead to Git merge conflicts. If this happens, you may need to manually resolve them with the help of the instructor or a student technical leader. Finally, please note that the Gradle plugin for GatorGrader will automatically download the newest version of GatorGrader.

Using Travis CI

This assignment uses Travis CI to automatically run GatorGrader and additional checking programs every time you commit to your GitHub repository. The checking will start as soon as you have accepted the assignment — thus creating your own private repository — and the course instructor and/or GitHub enables Travis for it. If you are using Travis for the first time, you will need to authorize Travis CI to access the private repositories that you created on GitHub. If you do not see either a yellow ● or a green ✔ or a red ✗ in your listing of commits, then please ask the instructor to see whether or not Travis CI was correctly enabled.

System Requirements

We developed this assignment to work with the following software and versions:

• Docker Desktop
• Operating Systems
  • Linux
  • MacOS
  • Windows 10 Pro
  • Windows 10 Enterprise
• Programming Language Tools
  • Gradle 5.4
  • MDL 0.5.0
  • OpenJDK 11.0.4
  • Proselint 0.10.2
  • Python 3.6 or 3.7

Reporting Problems

If you have found a problem with this assignment's provided source code or documentation, then you can go to the Computer Science 100 Fall 2019 Practical 3 repository and raise an issue. If you have found a problem with the GatorGrader tool and the way that it checks your assignment, then you can also raise an issue in that repository. To ensure that your issue is properly resolved, please provide as many details as is possible about the problem that you experienced. If you discover a problem with the assignment sheet for this project, then please raise an issue in the GitHub repository that provides the assignment sheets for your course.

Whenever possible, individuals who find, and use the appropriate GitHub issue tracker to correctly document, a mistake in any aspect of this assignment will receive free GitHub stickers and extra credit towards their grade for the project.

Receiving Assistance

If you are having trouble completing any part of this project, then please talk with either the course instructor or a student technical leader during the course session. Alternatively, you may ask questions in the Slack workspace for this course. Finally, you can schedule a meeting during the course instructor's office hours.

Project Assessment

Taking inspiration from the principles of specification-based grading, the grade that a student receives on this assignment will have the following characterization:

• Travis CI Build Status: Since additional checks on the source code or documentation may be encoded in Travis CI's actions and, moreover, all of the GatorGrader checks are also run in Travis CI, students will receive a checkmark grade if their last before-the-deadline build passes and a green ✔ appears in their GitHub commit log instead of a red ✗. Students are encouraged to repeatedly revise their source code and technical writing in an attempt to get their Travis CI build to pass.

All grades for this project will be reported through a student's GitHub repository using either messages in the GitHub commit log or issues raised in the issue tracker. Students should ask questions about their grade for this project in GitHub so as to facilitate an effective conversation about the submitted deliverables.