Paths: File paths (shared/, references/, ../ln-*) are relative to skills repo root. If not found at CWD, locate this SKILL.md directory and go up one level for repo root. If shared/ is missing, fetch files via WebFetch from https://raw.githubusercontent.com/levnikolaevich/claude-code-skills/master/skills/{path}.

Regression Checker

Runs the existing test suite to ensure no regressions after implementation changes.

Inputs

Resolution: Story Resolution Chain. Status filter: To Review

Purpose & Scope

• Detect test framework (pytest/jest/vitest/go test/etc.) and test dirs.
• Execute full suite; capture stdout/stderr for Story quality gate.
• Return PASS/FAIL with counts/log excerpts; never modifies Linear or kanban.
• Preserve full stdout/stderr output for downstream log analysis.

When to Use

• After code quality checks pass
• Code quality check passed

Workflow

Phase 0: Resolve Inputs

MANDATORY READ: Load shared/references/input_resolution_pattern.md, shared/references/ci_tool_detection.md

1. Resolve storyId: Run Story Resolution Chain per guide (status filter: [To Review]).

Phase 1: Execute Tests

MANDATORY READ: Load shared/references/output_normalization.md

Read target project files if they exist: docs/project/infrastructure.md, docs/project/runbook.md

1. Auto-discover test framework per ci_tool_detection.md Command Registry (Test Frameworks section).
2. Get service endpoints, port allocation from infrastructure.md. Get exact test commands, Docker setup, environment variables from runbook.md. Runbook commands take priority over auto-detection (per ci_tool_detection.md Discovery Hierarchy).
3. Build appropriate test command; run with timeout (5min per ci_tool_detection.md); capture stdout/stderr.
4. Parse results: passed/failed counts; key failing tests.
5. Normalize + group failures: Apply shared/references/output_normalization.md §1-§3 to test output. Group failing tests by error category (Import/Module, Assertion, Timeout, Type, Connection, Runtime). Report grouped: e.g., "3 Import errors in auth/, 2 Assertion mismatches in payment/".
6. Output verdict JSON (PASS or FAIL + grouped failures list) and add Linear comment.

Critical Rules

• No selective test runs; run full suite.
• Do not fix tests or change status; only report.
• Language preservation in comment (EN/RU).

Definition of Done

• Framework detected; command executed
• Results parsed; verdict produced with failing tests (if any)
• Linear comment posted with summary

Reference Files

• Risk-based limits used downstream: shared/references/risk_based_testing_guide.md
• CI tool detection: shared/references/ci_tool_detection.md
• Output normalization: shared/references/output_normalization.md
• Pytest patterns: references/pytest_configuration.md

Version: 3.1.0 Last Updated: 2026-01-09