004-branching.md

⏪ Branching and PR Overview | Pull Requests ⏩

Branching

Branching is the process of copying the master branch of a repository into another branch with a different name. Braching allows you to work on the project without affecting the master branch. You can, later, merge your changes to the master branch.

The following steps must be done by first

1. List current branches by issuing the command git branch (you can exit this view by pressing q). Record the results as your Answer to question 3

2. Create a new branch and make it the current branch.

   git branch header
   git checkout header

   Or create a new branch and switch to it using the single command:

   git checkout -b header

3. List current branches

   git branch

   Record the command output of git branch as your Answer to question 4

   Note: current branch is marked with *

4. Now you are working with branch header. Add a file called die.h with the following content, and save it.

   #ifndef DIE_H
   #define DIE_H
   #include <iostream>
   #include <fstream>
   using namespace std;
   
   class Die {
   public:
       /**
        * Die constructor:
        * Seed the random number generator, set the number of sides
        * to 6, and assign a random value (1-numSides) to faceValue
        */
       Die();
   
       /**
        * Die constructor:
        * Seed the random number generator, set the number of sides
        * to newNumSides, and assign a random value (1-numSides) to faceValue
        */
       Die(int newNumSides);
   
       /**
        * getFaceValue
        * @return the face value of the die
        */
       int getFaceValue();
   
       /**
        * getNumSides
        * @return the number of sides of the die
        */
       int getNumSides();
   
       /**
        * setNumSides: change the number of the die sides and ignore it if invalid
        * @param newNumSides
        */
       void setNumSides(int newNumSides);
   
       /**
        * roll: assign a new random value to the die face
        * @return the face value assigned
        */
       int roll();
   
       /**
        * operator <<, overloads the insertion operator to print
        * the face value of the die.
        * @return the stream used
        */
       friend ostream& operator <<(ostream &out, const Die &d);
   private:
       int faceValue; ///the face value of the die
       int numSides;  ///number of faces of the die
   };
   
   #endif

5. Add and commit the new file

6. Issue the ls command and record all file names as your Answer to question 5.

7. Switch back to the master branch:

   git checkout master

8. Issue the ls command again and record all file names as your Answer to question 6.

9. Is your header file in the master branch? Record your Answer to question 7

10. Let's merge the changes we made in the header branch into the master branch. First make sure you are in the master branch before merging.

git checkout master
git merge header

11. Issue the ls command again. You should see die.h file in the repository directory.
12. Push your changes to GitHub

The following steps must be done by second

Repeat the Branching steps above 1-12. Name your branch implement and add the file die.cc with the following content:

#include <iostream>
#include <fstream>
#include <cstdlib>
#include "die.h"
using namespace std;

//Constructors
Die::Die(){ //default 6 sides
    numSides = 6;
    srand(time(NULL));
    faceValue = rand() % numSides + 1;

}

Die::Die(int newNumSides){
    if (newNumSides > 1) {
        numSides = newNumSides;

    }
    else {
        numSides = 6;
    }
    srand(time(NULL));
    faceValue = rand() % numSides + 1;
}

//setters
void Die::setNumSides(int newNumSides){
    if (newNumSides > 1) {
        numSides = newNumSides;
    }
}

//getters
int Die::getFaceValue(){
    return faceValue;
}
int Die::getNumSides(){
    return numSides;
}

//helper functions
int Die::roll(){
    faceValue = rand() % numSides + 1;
    return faceValue;
}

ostream& operator <<(ostream &out, const Die &d){
    out << d.faceValue;
    return out;
}

Both teammates: Make sure you have no conflicts and both of your changes are posted on GitHub. All local and online repositories should be synched at this point.

The above workflow does not work when your teammate's input is required to approve the changes. In other words, this workflow works best if you don't have a partner.

In the next section, we will addres another workflow where each partner has to approve and comment on changes made to the repository. This a more realistic approach to team work. We will do this using pull requests.

⏪ Branching and PR Overview | Pull Requests ⏩