Semantic vs Stylistic Changes

In one sentence

Semantic changes alter observable behavior or contracts; stylistic changes alter presentation without intending to change meaning—reviewers must not treat them the same.

Why it matters

Agents and formatters produce large diffs full of whitespace, import order, and renames. If you skim everything equally, you miss the few hunks that change runtime behavior.

How it works

• Classify each hunk: behavior/contract change, pure style, generated output, or mixed.
• Review semantic hunks first: control flow, data shape, auth, API surface, migrations.
• Treat style-only hunks as noise unless they obscure semantic edits in the same file.
• Ask for semantic changes to be isolated from bulk formatting when the mix hides risk.
• Do not approve a “cleanup” PR until you have confirmed which hunks are not cleanup.

Example

Same PR, two kinds of edit:

Hunk A renames a local variable and rewraps lines. Hunk B changes when a session token is revoked. Spend review time on B; verify A does not accidentally alter equality or serialization along the way.