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

1. Capture the report: Restate the expected behavior, actual behavior, and reproduction steps.
2. Bound the scope: Identify whether the issue appears in request handling, domain logic, jobs, engine integration, or an external dependency.
3. Gather current evidence: Logs, error messages, edge-case inputs, recent changes, or missing guards.
4. Choose the first failing spec: Pick the boundary where the bug is visible to users or operators.
5. Define the smallest fix path: Name the likely files and the narrowest behavior change that should make the spec pass.
6. Hand off: Continue through rails-tdd-slices -> rspec-best-practices -> implementation skill.

Triage Output

Return findings in this shape:

1. Observed behavior
2. Expected behavior
3. Likely boundary
4. First failing spec to add
5. Smallest safe fix path
6. 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:

# spec/requests/orders/create_spec.rb
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

• assets/examples.md