What’s the effect of using git diff –minimal?

The git diff --minimal command is used in version control systems to view the differences between two sets of code in the most condensed or “minimal” way possible. It’s a part of the git diff command suite and is useful in analyzing the changes made in different versions of a project.

To understand git diff --minimal, you first need to understand the role of git diff. git diff is used to show changes between commits, commit and working tree, etc. It will show you what changes are being unstaged, or the differences between your working directory and the last commit.

The --minimal option changes the way git calculates the differences. Git has a sophisticated algorithm to calculate and present differences. It’s not just showing line-by-line differences; it also takes into account changes such as code block movement, renaming, and others. This often results in a more “human-friendly” diff, making it easier to understand the intention behind the changes. But this algorithm can sometimes be a bit slower especially when diffing large changes.

When you use --minimal, git tries to spend extra time to make sure that the smallest possible diff is produced. It generates a diff output where the number of deleted and added lines is as small as possible, regardless of how much time it takes. It’s trading off computation time for a potentially more compact presentation of changes.

For example, suppose you have two versions of a file where a few lines have been removed from the middle and added to the end. The “human-friendly” diff algorithm might show this as a block of removed lines and a block of added lines. But with --minimal, git will try to match up the identical lines, even though they are in different places, and show this as a block of lines that have moved.

So, git diff --minimal can be useful when you have large changes and you want to analyze the most “compact” differences. It might take a bit more time than the default algorithm, but the output can be more useful, particularly for complex changes.

Remember, --minimal is not always the best choice, it’s an option you can use when you want to see a compact diff at the cost of spending more computation time. It’s a tool in your toolbox that you can choose to use when it suits your needs.