
Reproduce Bug
- 315 installs
- 199k repo stars
- Updated August 5, 2026
- n8n-io/n8n
reproduce-bug is an n8n maintainer skill that reproduces Linear ticket bugs as failing regression tests for developers who need verified reproduction steps before patching workflow or node failures.
About
reproduce-bug is an n8n maintainer skill (n8n:reproduce-bug) that turns Linear ticket context into a failing regression test proving a reported bug. Given full ticket input—title, description, comments, error stacks, reproduction steps, and optional workflow JSON—the skill parses signals including affected area (node, execution engine, editor, API, or config), version where the bug broke, and last working version, then routes to the appropriate test strategy. Developers reach for reproduce-bug when triaging n8n workflow or node failures and needing a minimal reproducible test case maintainers can use to verify fixes and prevent regressions. The framework expects complete Linear ticket context as arguments and outputs a systematically derived failing test rather than ad-hoc manual reproduction notes.
- Minimal workflow isolation
- Execution data capture
- Version and environment notes
- Log-driven failure analysis
- Contributor-ready repro steps
Reproduce Bug by the numbers
- 315 all-time installs (skills.sh)
- Ranked #130 of 596 Debugging skills by installs in the Skillselion catalog
- Data as of Aug 5, 2026 (Skillselion catalog sync)
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| Installs | 315 |
|---|---|
| repo stars | ★ 199k |
| Last updated | August 5, 2026 |
| Repository | n8n-io/n8n ↗ |
How do you reproduce an n8n bug from a Linear ticket?
Reproduce reported n8n workflow or node failures with minimal executions, logs, versions, and environment notes so maintainers can verify, patch, and regression-test fixes.
Who is it for?
n8n maintainers and contributors triaging Linear bug tickets who need failing regression tests before writing patches for workflow or node failures.
Skip if: Developers outside the n8n codebase or teams without Linear ticket context including error stacks, reproduction steps, or workflow JSON attachments.
When should I use this skill?
A Linear ticket reports an n8n workflow or node failure and maintainers need a minimal failing regression test before patching.
What you get
A failing regression test, parsed reproduction signals, and routed test strategy covering the affected n8n component area.
- failing regression test
- parsed reproduction signals
Files
Bug Reproduction Framework
Given a Linear ticket context ($ARGUMENTS), systematically reproduce the bug with a failing regression test.
Step 1: Parse Signals
Extract the following from the provided ticket context:
- Error message / stack trace (if provided)
- Reproduction steps (if provided)
- Workflow JSON (if attached)
- Affected area (node, execution engine, editor, API, config, etc.)
- Version where it broke / last working version
Step 2: Route to Test Strategy
Based on the affected area, pick the test layer and pattern:
| Area | Test Layer | Pattern | Key Location |
|---|---|---|---|
| Node operation | Jest unit | NodeTestHarness + nock | packages/nodes-base/nodes/*/test/ |
| Node credential | Jest unit | jest-mock-extended | packages/nodes-base/nodes/*/test/ |
| Trigger webhook | Jest unit | mock IHookFunctions + jest.mock GenericFunctions | packages/nodes-base/nodes/*/test/ |
| Binary data | Jest unit | NodeTestHarness assertBinaryData | packages/core/nodes-testing/ |
| Execution engine | Jest integration | WorkflowRunner + DI container | packages/cli/src/__tests__/ |
| CLI / API | Jest integration | setupTestServer + supertest | packages/cli/test/integration/ |
| Config | Jest unit | GlobalConfig + Container | packages/@n8n/config/src/__tests__/ |
| Editor UI | Vitest | Vue Test Utils + Pinia | packages/frontend/editor-ui/src/**/__tests__/ |
| E2E / Canvas | Playwright | Test containers + composables | packages/testing/playwright/ |
Step 3: Locate Source Files
Find the source code for the affected area: 1. Search for the node/service/component mentioned in the ticket 2. Find the GenericFunctions file (common bug location for nodes) 3. Check for existing test files in the same area 4. Look at recent git history on affected files (git log --oneline -10 -- <path>)
Step 4: Trace the Code Path
Read the source code and trace the execution path that triggers the bug:
- Follow the call chain from entry point to the failure
- Identify the specific line(s) where the bug manifests
- Note any error handling (or lack thereof) around the bug
Step 5: Form Hypothesis
State a clear, testable hypothesis:
- "When [input/condition], the code does [wrong thing] because [root cause]"
- Identify the exact line(s) that need to change
- Predict what the test output will show
Step 6: Find Test Patterns
Look for existing tests in the same area: 1. Check test/ directories near the affected code 2. Identify which mock/setup patterns they use 3. Use the same patterns for consistency 4. If no tests exist, find the closest similar node/service tests as a template
Step 7: Write Failing Test
Write a regression test that:
- Uses the patterns found in Step 6
- Targets the specific hypothesis from Step 5
- Includes a comment referencing the ticket ID
- Asserts the CORRECT behavior (test will fail on current code)
- Also includes a "happy path" test to prove the setup works
Step 8: Run and Score
Run the test from the package directory (e.g., cd packages/nodes-base && pnpm test <file>).
Classify the result:
| Confidence | Criteria | Output |
|---|---|---|
| CONFIRMED | Test fails consistently, failure matches hypothesis | Reproduction Report |
| LIKELY | Test fails but failure mode differs slightly | Report + caveat |
| UNCONFIRMED | Cannot trigger the failure | Report: what was tried |
| SKIPPED | Hit a hard bailout trigger | Report: why skipped |
| ALREADY_FIXED | Bug no longer reproduces on current code | Report: when fixed |
Step 9: Iterate or Bail
If UNCONFIRMED after first attempt:
- Revisit hypothesis — re-read the code path
- Try a different test approach or layer
- Maximum 3 attempts before declaring UNCONFIRMED
Hard bailout triggers (stop immediately):
- Requires real third-party API credentials
- Race condition / timing-dependent
- Requires specific cloud/enterprise infrastructure
- Requires manual UI interaction that can't be scripted
Output: Reproduction Report
Present findings in this format:
---
Ticket: [ID] — [title] Confidence: [CONFIRMED | LIKELY | UNCONFIRMED | SKIPPED | ALREADY_FIXED]
Root Cause
[1-2 sentences explaining the bug mechanism]
Location
| File | Lines | Issue |
|---|---|---|
path/to/file.ts | XX-YY | Description of the problem |
Failing Test
path/to/test/file.test.ts — X/Y tests fail: 1. test name — [failure description]
Fix Hint
[Pseudocode or description of the fix approach]
---
Important
- DO NOT fix the bug — only reproduce it with a failing test
- Leave test files in place as evidence (don't commit unless asked)
- Run tests from the package directory (e.g.,
pushd packages/nodes-base && pnpm test <file> && popd) - Always redirect build output:
pnpm build > build.log 2>&1 - DO NOT look at existing fix PRs — the goal is to reproduce from signals alone
Related skills
FAQ
What input does n8n reproduce-bug require?
n8n reproduce-bug expects full Linear ticket context as input: title, description, comments, error messages or stack traces, reproduction steps, optional workflow JSON, affected area, and version signals for when the bug broke.
What does reproduce-bug output for n8n maintainers?
reproduce-bug systematically derives a failing regression test proving the reported bug. It parses ticket signals, routes to the correct test strategy by affected n8n area, and produces a minimal reproducible test case for patch verification.