Exercise: resolve a merge conflict¶

We have created a public repository that you can use to try resolving a merge conflict yourself. This repository includes some example data and a script that performs some basic data analysis.

First, obtain a local copy (a "clone") of this repository by running:

git clone https://github.com/robmoss/gimlb-simple-merge-example.git
cd gimlb-simple-merge-example

The repository history¶

You can inspect the repository history by running git log. Some key details to notice are:

The first commit created the following files:
README.md
LICENSE
analysis/initial_exploration.R
input_data/data.csv
The second commit created the following file:
outputs/summary.csv

This commit has been given the tag first_milestone.

From this first_milestone tag, two branches were created:
The feature/second-data-set branch adds a second data set and updates the analysis script to inspect both data sets.
The feature/calculate-rate-of-change branch changes which summary statistics are calculated for the original data set.
The example-solution branch merges both feature branches and resolves any merge conflicts. This branch has been given the tag second_milestone.

Your task¶

You will start with the master branch, which contains the commits up to the first_milestone tag, and then merge the two feature branches into this branch, resolving any merge conflicts that arise. You can then compare your results to the example-solution branch.

Obtain a local copy of this repository, by running:

git clone https://github.com/robmoss/gimlb-simple-merge-example.git
cd gimlb-simple-merge-example

Create local copies of the two feature branches and the example solution, by running:

git checkout feature/second-data-set
git checkout feature/calculate-rate-of-change
git checkout example-solution

Return to the master branch, by running:
```
git checkout master
```
Merge the feature/second-data-set branch into master, by running:
```
git merge feature/second-data-set
```
Merge the feature/calculate-rate-of-change branch into master, by running:
```
git merge feature/calculate-rate-of-change
```

This will result in a merge conflict, and now you need to decide how to resolve each conflict! Once you have resolved the conflicts, create a commit that records all of your changes (see the previous chapter for an example).

Tip

You may find it helpful to inspect the commits in each of the feature branches to understand how they have changed the files in which the conflicts have occurred.

Self evaluation¶

Once you have created a commit that resolves these conflicts, see how similar or different the contents of your commit are to the corresponding commit in the example-solution branch (which has been tagged second_milestone). You can inspect this commit by running:

git show example-solution

You can compare this commit to your solution by running:

git diff example-solution

How does your resolution compare to this commit?

Note

You may have resolved the conflicts differently to the example-solution branch, and that's perfectly fine as long as they have the same effect.

Example solution¶

Here we present a recorded terminal session in which we clone this repository and resolve the merge conflict.

Tip

You can use the video timeline (below) to jump to specific moments in this exercise. Remember that you can pause the recording at any point to select and copy any of the text.

Resolving a merge conflict

Video timeline: