| name | rails-bug-triage |
| license | MIT |
| description | Use when investigating a bug, error, or regression in a Ruby on Rails codebase. Creates a failing RSpec reproduction test, isolates the broken code path, and produces a minimal fix plan. Trigger words: debug, broken, error, regression, stack trace, failing test, RSpec, bug report, Rails app.
|
Rails Bug Triage
Use this skill when a bug report exists but the right reproduction path and fix sequence are not yet clear.
Core principle: Do not guess at fixes. Reproduce the bug, choose the right failing spec, then plan the smallest safe repair.
Process
- Capture the report: Restate the expected behavior, actual behavior, and reproduction steps.
- Bound the scope: Identify whether the issue appears in request handling, domain logic, jobs, engine integration, or an external dependency.
- Gather current evidence: Logs, error messages, edge-case inputs, recent changes, or missing guards.
- Choose the first failing spec: Pick the boundary where the bug is visible to users or operators.
- Define the smallest fix path: Name the likely files and the narrowest behavior change that should make the spec pass.
- Hand off: Continue through
rails-tdd-slices -> rspec-best-practices -> implementation skill.
Triage Output
Return findings in this shape:
- Observed behavior
- Expected behavior
- Likely boundary
- First failing spec to add
- Smallest safe fix path
- Follow-up skills
Example (wrong status code bug):
1. Observed: POST /orders returns 500 when product is out of stock
2. Expected: Returns 422 with { error: "Out of stock" }
3. Boundary: Request layer — visible in HTTP contract
4. First spec: spec/requests/orders/create_spec.rb
5. Fix path: Orders::CreateOrder should return { success: false, error: "Out of stock" }
when inventory check fails; controller renders 422
6. Next: rails-tdd-slices → write request spec → rspec-best-practices → fix
Skeleton failing spec:
RSpec.describe "POST /orders", type: :request do
context "when product is out of stock" do
let(:product) { create(:product, stock: 0) }
it "returns 422 with an error message" do
post orders_path, params: { order: { product_id: product.id, quantity: 1 } }, as: :json
expect(response).to have_http_status(:unprocessable_entity)
expect(response.parsed_body["error"]).to eq("Out of stock")
end
end
end
Run it before implementing the fix: bundle exec rspec spec/requests/orders/create_spec.rb
Boundary Guide
See BOUNDARY_GUIDE.md for the full bug-shape → spec-type mapping and layer diagnosis tips.
Quick reference:
| Bug shape | Likely first spec |
|---|
| HTTP symptoms (status, JSON, redirect) | Request spec |
| Data symptoms (wrong value, validation) | Model or service spec |
| Timing symptoms (missing job, email) | Job spec |
| Engine routing/generator regression | Engine spec in dummy app |
Pitfalls
| Pitfall | What to do |
|---|
| Unit spec when the bug is visible at request level | Start where the failure is actually observed |
| Bundling reproduction, refactor, and new features | Fix the bug in the smallest safe slice only |
| Flaky evidence treated as green light to patch | Stabilize reproduction before touching code |
| The explanation relies on "probably" or "maybe" | Ambiguity means the reproduction step isn't done yet |
Integration
| Skill | When to chain |
|---|
| rails-tdd-slices | To choose the strongest first failing spec for the bug |
| rspec-best-practices | To run the TDD loop correctly after the spec is chosen |
| refactor-safely | When the bug sits inside a risky refactor area and behavior must be preserved first |
| rails-code-review | To review the final bug fix for regressions and missing coverage |
| rails-architecture-review | When the bug points to a deeper boundary or orchestration problem |
Assets
