Google's Git Killer Is INSANELY Better (and it's open source)

Summary

In this video, the speaker introduces Jiujutsu (JJ), an innovative version control system that simplifies and enhances workflows compared to traditional Git. JJ eliminates the need for staging and commit indexes, automatically staging all changes and allowing dynamic, ongoing changes. It features powerful tools like squash, rebase, and conflict resolution, making it easier to manage multiple edits and branches. The system uses anonymous branches and merges changes seamlessly without requiring manual resets. By demonstrating these features, the video encourages developers to explore JJ as a more intuitive and flexible alternative to Git for version control.

Takeaways

• 😀 JJ, a version control system written in Rust, introduces an alternative to Git with some significant workflow improvements.
• 🚗 JJ works similarly to Git but eliminates the need for staging and offers a dynamic change tracking system, making it more flexible for developers.
• ⚡ Unlike Git, JJ doesn't use an index (staging area); instead, everything is considered 'staged' until the change is finalized.
• 🛠️ One of JJ's strengths is its ability to undo changes and allows you to work dynamically by rolling back or redoing modifications.
• 💡 The 'JJ squash' command combines multiple changes into one commit, updating both the commit hash and the timestamp, improving history management.
• ⏱️ JJ's rebase functionality always succeeds, even when conflicts arise, offering a powerful way to manage commit histories without breaking workflows.
• 🛑 JJ simplifies branching by not using traditional branches. Instead, 'anonymous branches' are created dynamically based on different parents.
• 🖋️ You can add descriptions to changes, even multiple times, to clarify what the modification does, making it easier to track.
• 💻 Conflict resolution in JJ is handled smoothly through a specialized 'resolve' command that allows developers to interactively choose changes during conflicts.
• 🎯 With JJ, developers can manage version control and branching workflows in a highly flexible and efficient way, making it a great alternative to Git for certain use cases.

Q & A

What is Jiujutsu (JJ), and how does it relate to Git?

Jiujutsu (JJ) is a version control system designed as a better alternative to Git. While Git acts as the underlying database for JJ, JJ operates as a client to manage and track changes more dynamically and fluidly, eliminating the need for a staging area like Git's index. JJ allows for continuous evolution of changes and integrates features like automatic rebasing and squash commits, improving workflow efficiency.

What is the main difference between JJ and Git's approach to changes?

The key difference is that JJ doesn't use Git's index or staging area. In JJ, every change is treated as a dynamic, ongoing creation. Changes don't have a clear end but evolve until a new change starts. This continuous change process eliminates the traditional 'commit' concept, with changes being described and managed over time.

How does JJ handle commits differently from Git?

In JJ, commits are referred to as 'changes,' and they are dynamic, meaning they don’t have a fixed end point. A change evolves as you add more modifications, and the commit's hash and timestamp will change when you combine multiple changes (using squash). JJ eliminates the need for committing with fixed endpoints, making the process more flexible.

What is the significance of the 'at' sign in JJ?

The 'at' sign in JJ represents the change ID being actively edited. It marks the current working copy's state, indicating that the change is still in progress. As you move through different changes, the 'at' sign helps identify which version you're working with.

How does JJ handle 'undo' operations?

JJ has a built-in 'undo' command that reverts the last change. This feature makes it easy to revert mistakes and start fresh from the last stable state without the complexity of using 'git reset' in Git. The undo operation simplifies error recovery in a workflow.

What is the 'squash' feature in JJ, and how is it different from Git's squash?

The 'squash' feature in JJ allows you to combine multiple changes into a single commit. Unlike Git, where you need to use commands like 'git rebase' to squash commits, JJ allows you to squash changes interactively without needing to address an existing change. It also allows you to squash changes selectively, even targeting specific files or hunks of code.

What is a key advantage of JJ's 'branchless' workflow?

The 'branchless' workflow in JJ eliminates the need for named branches, making version control simpler and less prone to errors. JJ treats changes as unnamed, anonymous branches, and instead of switching between named branches, you create new changes based on previous ones. This allows for a more flexible and dynamic branching mechanism without the overhead of managing branch names.

How does JJ handle conflicts during rebasing?

In JJ, rebasing always succeeds, even when there are conflicts. If conflicts arise, JJ automatically flags them and gives users the tools to resolve them easily. Users can use the 'edit' command to address conflicts, and JJ offers a resolve interface to choose which changes to keep or discard. This smooth conflict resolution ensures that the rebase process doesn't get stuck.

What does the 'rebase' command do in JJ?

The 'rebase' command in JJ allows you to move a change on top of another, similar to Git’s rebase functionality. However, in JJ, the rebase command will always succeed, regardless of conflicts. It automatically handles conflict resolution, making rebasing a smoother and less error-prone process.

How does JJ manage changes without traditional branches?

JJ doesn't use traditional branches. Instead, it creates anonymous branches by linking new changes to previous ones, creating a dynamic tree of changes. You can merge different paths or changes into one by referencing multiple parents in a new change, which eliminates the need for managing named branches and simplifies merging and rebasing.