Vanilla Rails Work Breakdown

Core Rule

Each PR = one sentence. Target 2-5 files, max 7-8.

If you can't describe the PR in one sentence, split it.

CRITICAL: If your PR description uses "and", STOP and split it.

Bundle Together

• Model + tests (but NOT scopes/sorting)
• Controller + view + tests
• Migration + model using it
• Routes + controller they configure

Tests go with the functional change, never with styling.

Keep Separate (ALWAYS)

Each of these MUST be its own PR:

• Bug fixes
• Refactoring
• Styling/CSS (even one line)
• Filters (even simple params)
• Sort options (including scopes like pinned_first)

Example: Card Pinning

Wrong (3 PRs):

1. "Add pinning to cards with sorting" (model + sorting scope + tests)
2. "Add UI for pinning" (controller + views + tests)
3. "Add filtering and styling" (filter + CSS)

Right (5 PRs):

1. "Add pinning to cards" (migration + model methods + tests, 3 files)
2. "Add UI for pinning cards" (controller + view + tests, 4 files)
3. "Sort pinned cards first" (scope + tests, 2 files)
4. "Add filter for pinned cards" (controller param + view + tests, 3 files)
5. "Style pinned cards" (CSS, 1 file)

Commit Messages

Present tense, no prefixes:

Add hotkeys for triaging cards
Fix HTML injection in webhook titles
Expose card ID on comments

Not: feat:, fix:, WIP:

Red Flags

Stop and split if:

• More than 7-8 files
• PR title has "and"
• Mixing refactoring with features
• Bug fix included with feature

Bug During Feature Work

1. Branch from main for bug fix
2. Fix + test in separate PR
3. Return to feature branch
4. Rebase after bug fix merges

Never bundle bug fixes with feature PRs.

One Sentence Test

✅ "This PR adds pinning to cards" ❌ "This PR adds pinning, styling, and filters"

If you use "and", split the PR.

Common Rationalizations (STOP)

Excuse	Reality
"Sorting is part of the model concern"	No. Sorting is a feature that ships separately. Core pinning works without sorting.
"Styling and filtering touch the same view"	Different concerns. Filtering is functional, styling is visual. Separate PRs.
"More efficient to bundle them"	37signals values small PRs over efficiency. 2-5 files is the target.
"They're logically grouped"	"Logical grouping" is not the test. One sentence without "and" is the test.
"Just a few lines of CSS"	Styling ALWAYS separate. Even one line.
"Just a tiny partial"	View code goes with controller, not model. Size irrelevant.
"It's related functionality"	Each feature = one PR. Even if related. One sentence test applies.
"The change is trivial"	Size doesn't matter. Separate concerns = separate PRs.