What is test-coverage?

A test-coverage workflow that adds and improves automated tests for a chosen part of a codebase, aiming for 90% coverage. Test coverage measures how much code is run by tests.

Use it to inspect a target area, measure its current coverage, choose meaningful files to test, and iteratively write or refactor tests.

It helps find untested branches, state changes, and side effects before they cause regressions. It can also work from a directory or a Jira ticket, a project-tracking record.

test-coverage — Skill for Claude Code and Codex by LedgerHQ: A test-coverage workflow that adds and improves automated tests…

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add skills/ledgerhq/ledger-live/test-coverage

Any agent

npx skills add LedgerHQ/ledger-live --skill test-coverage

Clone the repo

git clone --depth 1 https://github.com/LedgerHQ/ledger-live

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ledgerhq/ledger-live/test-coverage.svg)](https://agentmods.dev/skills/ledgerhq/ledger-live/test-coverage)

Your own site

<a href="https://agentmods.dev/skills/ledgerhq/ledger-live/test-coverage"><img src="https://agentmods.dev/badge/skills/ledgerhq/ledger-live/test-coverage.svg" alt="Measured on agentmods" height="20"></a>

Per session 21 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 736 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5	$0.00021	$0.00736
Opus 5	$0.00010	$0.00368
Sonnet 5	$0.00004	$0.00147
Haiku 4.5	$0.00002	$0.00074

Measured 5d ago against content hash 99e4fce012a6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

test-coverage scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/test-coverage/SKILL.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Test Coverage

Increase test coverage to 90% on a target zone with iterative writing and refactoring.

Prompt Variables

$TARGET_ZONE

Directory path or Jira ticket URL for the zone to cover (e.g., src/mvvm/features/Accounts/ or https://ledgerhq.atlassian.net/browse/LIVE-1234)

Instructions

Follow all conventions from the testing skill (.agents/skills/testing/SKILL.md). Delegate test execution to the test-runner subagent throughout.

Step 1: Scope and Analyze

If $TARGET_ZONE is a Jira URL, fetch the ticket via Atlassian MCP and extract affected files.
Use code-explorer subagent to analyze the zone: trace execution paths, map dependencies, and identify branching logic worth testing.

Measure current coverage:

pnpm <mobile|desktop> test:jest --coverage \
  --collectCoverageFrom='<zone-glob>' \
  --coverageReporters=text-summary

From the code-explorer analysis, build the list of files to test. Skip type definitions, barrel re-exports, and thin wrappers with no branching.
For each remaining file, ask:
- Does it contain branching logic, state transitions, or side effects?
- Would a regression break user-facing behavior?
- Is it already covered indirectly by a parent test? If all answers are no, skip.

Step 2: Write Tests

Order: pure utils -> hooks -> viewModels -> components with side effects.

For each file:

Search existing mocks/fixtures/factories before creating new ones (see testing skill).
Write tests following all testing skill conventions.
Run tests via test-runner. Fix failures before moving to the next file.

Loop until coverage >= 90%.

Step 3: Refactoring Loop

Three sequential passes. After each pass, run tests via test-runner -- they must still pass before the next pass.

Pass 1 -- Audit mocks

For every mock (jest.mock, jest.fn, mockReturnValue, jest.spyOn): is it asserted directly or does it enable a code path whose output is asserted?
Remove any mock that satisfies neither. Simplify over-specified mocks.

Read the full file on GitHub · 80 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

5d ago First seen · 80 lines · 21 tokens per session scan A 99e4fce012a6

Subscribe to this mod's changes

test-coverage is a skill published in the GitHub repository LedgerHQ/ledger-live (615 stars, last pushed today), licensed MIT. It adds 21 tokens to every session and 736 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Testing Writing and docs ledger-live ledger-wallet

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