Merge strategies

Merge commit preserves the full branch history, creating a separate merge commit. Squash merge combines all PR commits into one clean commit. Rebase merge rewrites feature commits on top of the main branch, forming a linear history without merge commits.

Merge Commit

• Creates an additional merge commit.
• Preserves a non-linear, but accurate history.
• Does not rewrite existing commits → safe for the team.

History:

A---B---C---------G
     \           /
      D---E-----F

Pros:

• Full transparency of history.
• Convenient to track the origin of changes.
• Safe for shared branches.

Cons:

• More "noisy", branched history.

Squash Merge

• Turns all PR commits into one final commit.
• Internal commits of the feature are not saved.

History:

A---B---C---X

Pros:

• Clean, concise history.
• One commit is easy to revert.
• Less "trash" in git log.

Cons:

• The internal structure of development is lost.
• No information on how the feature evolved.

Rebase Merge

• Rewrites feature commits, "transferring" them to the new branch base.
• History becomes linear, no merge commit is created.

Before:

main:     A---B---C
feature:      \ D---E

After:

A---B---C---D'---E'

Pros:

• Clean linear history.
• All feature commits are preserved.
• Easy to read git log.

Cons:

• Rewrites history → dangerous for shared branches.
• Possible conflicts on each commit.

When to use which strategy

Use Merge Commit if:

• Transparent history of branching is needed.
• There are many collaborators on the project.
• PRs are large and long-lived.
• History should not be rewritten.

Use Squash Merge if:

• Need to keep main as clean as possible.
• Feature commits are "WIP", small and unimportant.
• Functionality is often reverted.
• Team wants one commit per feature.

Use Rebase Merge if:

• Want a linear history without merge commits.
• Feature is local, not shared.
• Important to preserve detailed commits.
• Team is not afraid of history rewriting.

Key Ideas

• Merge Commit → safe, preserves history, but makes it non-linear.
• Squash Merge → cleanest history, but without details.
• Rebase Merge → linearity + full detailing, but dangerous for shared branches.
• The right strategy depends on the team culture and history requirements.