Cross-Layer Check

Note: This is a post-implementation safety net. Ideally, read the Pre-Implementation Checklist before writing code.

Related Documents

/trellis:check-cross-layer

Execution Steps

1. Identify Change Scope

git status
git diff --name-only

2. Select Applicable Check Dimensions

Dimension A: Cross-Layer Data Flow (Required when 3+ layers)

routes/

api/

handlers/

controllers/

services/

lib/

core/

domain/

db/

models/

repositories/

schema/

components/

views/

templates/

pages/

utils/

helpers/

common/

• Read flow: Database -> Service -> API -> UI
• Write flow: UI -> API -> Service -> Database
• Types/schemas correctly passed between layers?
• Errors properly propagated to caller?
• Loading/pending states handled at each layer?

.trellis/spec/guides/cross-layer-thinking-guide.md

Dimension B: Code Reuse (Required when modifying constants/config)

• Modifying UI constants (label, icon, color)
• Modifying any hardcoded value
• Seeing similar code in multiple places
• Creating a new utility/helper function
• Just finished batch modifications across files

• Search first: How many places define this value?
  bash

  # Search in source files (adjust extensions for your project)
  grep -r "value-to-change" src/

• If 2+ places define same value -> Should extract to shared constant
• After modification, all usage sites updated?
• If creating utility: Does similar utility already exist?

.trellis/spec/guides/code-reuse-thinking-guide.md

Dimension B2: New Utility Functions

• Search for existing similar utilities first
  bash

  grep -r "functionNamePattern" src/

• If similar exists, can you extend it instead?
• If creating new, is it in the right location (shared vs domain-specific)?

Dimension B3: After Batch Modifications

• Did you check ALL files with similar patterns?
  bash

  grep -r "patternYouChanged" src/

• Any files missed that should also be updated?
• Should this pattern be abstracted to prevent future duplication?

Dimension C: Import/Dependency Paths (Required when creating new files)

• Using correct import paths (relative vs absolute)?
• No circular dependencies?
• Consistent with project's module organization?

Dimension D: Same-Layer Consistency

• Modifying display logic or formatting
• Same domain concept used in multiple places

• Search for other places using same concept
  bash

  grep -r "ConceptName" src/

• Are these usages consistent?
• Should they share configuration/constants?

Common Issues Quick Reference

grep

Output

1. Which dimensions your changes involve
2. Check results for each dimension
3. Issues found and fix suggestions