ln-404-test-executor

name	ln-404-test-executor
description	Executes test tasks (label 'tests') through Todo to To Review with risk-based limits. Use for test task execution. Not for implementation tasks.
allowed-tools	Read, Grep, Glob, Bash, mcp__hex-line__outline, mcp__hex-line__read_file, mcp__hex-line__edit_file, mcp__hex-line__write_file, mcp__hex-line__verify, mcp__hex-line__changes, mcp__hex-line__inspect_path
license	MIT

Paths: File paths (references/, ../ln-*) are relative to this skill directory.

Test Task Executor

Type: L3 Worker

Runs a single Story final test task (label "tests") through implementation/execution to To Review.

Purpose & Scope

• Handle only tasks labeled "tests"; other tasks go to ln-401.
• Follow the 11-section test task plan (E2E/Integration/Unit, infra/docs/cleanup).
• Enforce risk-based constraints: Priority ≥15 scenarios covered; each test passes Usefulness Criteria; no framework/DB/library/performance tests.
• Update tracker/kanban for this task only: Todo -> In Progress -> To Review.

Hex-line acceleration (if available): Use outline(file_path) before reading test targets. Use narrow inspect_path(path=<relevant test dir>) to understand test structure; if you intentionally need a full broad inventory of tests/, opt in with max_entries=0 instead of assuming the default pattern cap will show everything. Use grep_search(output_mode="summary") first to find tests/helpers/fixtures, then escalate to output_mode="content", edit_ready=true only when you need canonical hunks for a follow-up edit; use allow_large_output=true only as an explicit override. Use read_file() and edit_file() as the primary path for test/code/config files. Keep read_file() in discovery mode for normal inspection; use read_file(edit_ready=true, verbosity="full") before edits that need revision/checksum protocol. Use verify() and changes() before handoff. Built-in Read/Edit are fallback only when hex-line is unavailable.

Inputs

Input	Required	Source	Description
taskId	Yes	args, parent Story, kanban, user	Test task to execute

Resolution: Task Resolution Chain. Status filter: Todo (label: tests)

Task Storage Mode

MANDATORY READ: Load references/environment_state_contract.md, references/storage_mode_detection.md, references/tracker_provider_contract.md, and references/input_resolution_pattern.md

MANDATORY READ: Load references/ci_tool_detection.md — compact output flags, pipefail, normalization-before-truncation policy for test command execution.

Extract: task_provider = Task Management → Provider (linear | github | file). Operations stay provider-agnostic in this skill — see references/tracker_provider_contract.md for the canonical operation set and provider_*.md for transport binding.

Tracker operations used by this skill: getTask, getStory, updateStatus (Todo → In Progress → To Review), addComment (test results). Transport per provider lives in references/provider_file.md, references/provider_github.md, references/provider_linear.md.

MANDATORY READ: Load references/mcp_tool_preferences.md — ALWAYS use hex-line MCP for code files when available. No fallback to standard Read/Edit unless hex-line is down.

Workflow (concise)

1. Resolve taskId: Run Task Resolution Chain per guide (status filter: [Todo, label: tests]).
2. Load task: Fetch full test task description via the configured tracker provider (getTask); read linked guides/manuals/ADRs/research; review parent Story (getStory) and manual test results if provided. 2b) Goal gate: MANDATORY READ: Load references/goal_articulation_gate.md — State REAL GOAL of these tests (which business behavior must be verified, not "write tests"). NOT THE GOAL: testing infrastructure or framework behavior instead of business logic. HIDDEN CONSTRAINT: which existing tests might break from implementation changes.
3. Read environment docs: Read docs/project/infrastructure.md — get server IPs, ports, service endpoints. Read docs/project/runbook.md — understand test environment setup, Docker commands, test execution prerequisites. Use exact commands from runbook.
4. Validate plan: Check Priority ≥15 coverage and Usefulness Criteria; ensure focus on business flows (no infra-only tests).
5. Start work: Set task In Progress via the configured tracker provider (updateStatus); move in kanban.
6. Implement & run: MANDATORY READ: Load references/code_efficiency_criterion.md — Author/update tests per plan; reuse existing fixtures/helpers; run tests; fix failing existing tests; update infra/doc sections as required. Before handoff, verify 3 efficiency self-checks (especially: reuse fixtures instead of duplicating setup).
7. Complete: Ensure counts/priority still within limits; set task To Review; move in kanban; add comment summarizing coverage, commands run, and any deviations.

Critical Rules

• Single-task only; no bulk updates.
• Do not mark Done; the reviewer approves. Task must end in To Review.
• Keep language (EN/RU) consistent with task.
• No framework/library/DB/performance/load tests; focus on business logic correctness (not infrastructure throughput).
• Respect limits and priority; if violated, stop and return with findings.
• Do NOT commit. Leave all changes uncommitted — the reviewer reviews and commits.

Runtime Summary Artifact

MANDATORY READ: Load references/coordinator_summary_contract.md, references/worker_runtime_contract.md, references/task_worker_runtime_contract.md

Shared contract:

• emit summary_kind=task-status
• standalone mode omits runId and summaryArtifactPath
• managed mode passes both runId and exact summaryArtifactPath before the worker writes its validated summary

Monitor (2.1.98+): For test/coverage commands expected >30s, use Monitor. Fallback: Bash(run_in_background=true).

Definition of Done

• Task identified as test task and set to In Progress; kanban updated
• Plan validated (priority/limits) and guides read
• Tests implemented/updated and executed; existing failures fixed
• Docs/infra updates applied per task plan
• Task set to To Review; kanban moved; summary comment added with commands and coverage
• Runtime summary artifact written to the shared task-status location.

Test Failure Analysis Protocol

CRITICAL: When a newly written test fails, STOP and analyze BEFORE changing anything (failing new tests often indicate implementation bugs, not test issues — fixing blindly masks root cause).

Step 1: Verify Test Correctness

• Does test match AC requirements exactly? (Given/When/Then from Story)
• Is expected value correct per business logic?
• If uncertain: Query ref_search_documentation(query="[domain] expected behavior")

Step 2: Decision

Test matches AC?	Action
YES	BUG IN CODE → Fix implementation, not test
NO	Test is wrong → Fix test assertion
UNCERTAIN	MANDATORY: Query MCP Ref + ask user before changing

Step 3: Document in tracker comment (addComment) "Test [name] failed. Analysis: [test correct / test wrong]. Action: [fixed code / fixed test]. Reason: [justification]"

RED FLAGS (require user confirmation):

• ⚠️ Changing assertion to match actual output ("make test green")
• ⚠️ Removing test case that "doesn't work"
• ⚠️ Weakening expectations (e.g., toContain instead of toEqual)

GREEN LIGHTS (safe to proceed):

• ✅ Fixing typo in test setup/mock data
• ✅ Fixing code to match AC requirements
• ✅ Adding missing test setup step

Test Writing Principles

1. Strict Assertions - Fail on Any Mismatch

Use exact match assertions by default:

Strict (PREFER)	Loose (AVOID unless justified)
Exact equality check	Partial/substring match
Exact length check	"Has any length" check
Full object comparison	Partial object match
Exact type check	Truthy/falsy check

WARN-level assertions FORBIDDEN - test either PASS or FAIL, no warnings.

2. Expected-Based Testing for Deterministic Output

For deterministic responses (API, transformations):

• Use snapshot/golden file testing for complex deterministic output
• Compare actual output vs expected reference file
• Normalize dynamic data before comparison (timestamps → fixed, UUIDs → placeholder)

3. Golden Rule

"If you know the expected value, assert the exact value."

Forbidden: Using loose assertions to "make test pass" when exact value is known.

Reference Files

• Environment state: references/environment_state_contract.md
• Storage mode operations: references/storage_mode_detection.md
• Kanban format: docs/tasks/kanban_board.md
• MANDATORY READ: Load references/research_tool_fallback.md

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Version: 3.2.0 Last Updated: 2026-01-15