From First Commit to Latest -Tracing the Journey of Open Source Projects

The journey of a thousand miles begins with one step. – Lao Tzu

Open-source projects are a treasure trove of knowledge, showcasing the collaborative efforts and coding practices of developers worldwide. Analyzing the commit history of such projects can provide valuable insights into their evolution, development decisions, and coding standards. This guide will take you through a detailed process of reviewing an open-source project’s commit history using Git, from the initial commit to the latest updates. Analyzing an open-source project’s commit history can deepen our understanding of software development practices and project evolution. By systematically reviewing each commit, we can learn from the collective expertise of the project’s contributors.

Why Analyze Commit Histories?

Understanding the progression of a project can offer numerous benefits:

  • Learning Best Practices: See how experienced developers structure their code, manage features, and fix bugs.
  • Tracing Project Evolution: Gain insights into how the project evolved, what challenges were faced, and how they were resolved.
  • Identifying Key Contributors: Recognize the significant contributions and contributors to the project.
  • Improving Your Code: Apply learned techniques and practices to your own projects.

Start Tracing Process

We will take the example of Gin, which is one of most popular anf fast HTTP web framework in the go ecosystem . We will start by cloning the repository locally .

$ git clone https://github.com/gin-gonic/gin.git
$ cd gin

To go through the commits from the start, we can use the following command -

$ git log --reverse --oneline
15216a0 Initial commit
d10e2b6 Improves README.md
1565111 Fixes routing bug
40dc444 Renames ErrorRender() to ErrorLogger()
bf1ecfc (tag: v0.1) Changes behaviour of ErrorLogger() and Logger()
899a711 update Readme.md. Add code to String method
b6bd5b0 Add MIT license
c3ac6f9 readme: small fixes
42c577d Fixing quotes
b462c3b Merge pull request #3 from LinusU/patch-1
686738f Merge pull request #2 from adammck/add_mit_license

To check the changes of those individual commit,

$ git show  15216a0
commit 15216a0883d113fadc33198d24850974eae0f841
Author: Manu Mtz-Almeida <manu.valladolid@gmail.com>
Date:   Wed Jun 18 01:42:34 2014 +0200

    Initial commit

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..f910801
--- /dev/null
+++ b/README.md
@@ -0,0 +1,277 @@
+#Gin Web Framework
+Gin is a web framework written in Golang. It features a martini-like API with much better performance, up to 40 times faster. If you need performance and good productivity, you will love Gin.
+[Check out the official web site](http://gingonic.github.com)
+
+## Start using it
+Run:
+
+```
+go get github.com/gin-gonic/gin
+```
+Then import it in your Golang code:
+

Checking individual commits for changes consumes a lot of time and will soon become un-productive as we go on. To avoid this problem I wrote a simple bash script to automate this process and go through the commits sequentally.

$ vim review_commits.sh

#!/bin/bash

# Check if the script is being run inside a Git repository
if ! git rev-parse --is-inside-work-tree > /dev/null 2>&1; then
    echo "This script must be run inside a Git repository."
    exit 1
fi

# Get all commit hashes in reverse order
commit_hashes=$(git log --reverse --pretty=format:"%H")

# Function to display the current commit details
show_commit() {
    local commit_hash=$1
    echo "Commit: $commit_hash"
    git show --stat $commit_hash
}

# Function to handle user input
prompt_user() {
    echo "Options:"
    echo "  [Enter] to continue to the next commit"
    echo "  [s]kip to the next commit without reviewing"
    echo "  [q]uit the script"
    read -p "Enter your choice: " choice
}

# Loop through each commit hash
for commit_hash in $commit_hashes; do
    git checkout $commit_hash --quiet
    show_commit $commit_hash
    prompt_user

    case $choice in
        s|S)
            echo "Skipping to the next commit..."
            continue
            ;;
        q|Q)
            echo "Exiting the script."
            break
            ;;
        *)
            echo "Continuing to the next commit..."
            ;;
    esac
done

# Return to the latest commit on the main branch (adjust branch name if necessary)
git checkout main --quiet
git pull --quiet

echo "Review process complete. You are now on the latest commit of the 'main' branch."

Then run the script by:-

$ bash review_commits.sh

Please commit your changes or stash them before you switch branches.
Aborting
Commit: 15216a0883d113fadc33198d24850974eae0f841
commit 15216a0883d113fadc33198d24850974eae0f841
Author: Manu Mtz-Almeida <manu.valladolid@gmail.com>
Date:   Wed Jun 18 01:42:34 2014 +0200

    Initial commit

 README.md                 | 277 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 auth.go                   |  83 +++++++++++++++++
 examples/example_basic.go |  55 +++++++++++
 gin.go                    | 377 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 logger.go                 |  20 ++++
 recovery.go               |  97 ++++++++++++++++++++
 validation.go             |  56 ++++++++++++
 7 files changed, 965 insertions(+)
Options:
  [Enter] to continue to the next commit
  [s]kip to the next commit without reviewing
  [q]uit the script
Enter your choice:
Continuing to the next commit...
error: Your local changes to the following files would be overwritten by checkout:
        .github/ISSUE_TEMPLATE.md
        .github/PULL_REQUEST_TEMPLATE.md
        .github/dependabot.yml
        .github/workflows/codeql.yml
        .github/workflows/gin.yml
        .github/workflows/goreleaser.yml
        .gitignore
        ..
        ..
        tree_test.go
        utils.go
        utils_test.go
        version.go
Please commit your changes or stash them before you switch branches.
Aborting
Commit: d10e2b6c0dfcc8524cda504f11130bf78b7fe563
commit d10e2b6c0dfcc8524cda504f11130bf78b7fe563
Author: Manu Mtz-Almeida <manu.valladolid@gmail.com>
Date:   Mon Jun 30 03:58:10 2014 +0200

    Improves README.md

 README.md | 53 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 33 insertions(+), 20 deletions(-)
Options:
  [Enter] to continue to the next commit
  [s]kip to the next commit without reviewing
  [q]uit the script
Enter your choice:

Since it is difficult to visualize the changes in the terminal, It is recommend to open the repo in a text editor to check the changes. With the above script, you can sequentially trace the evolution of the project.