Find coverage gaps, generate tests, and fix failing tests with an agentic loop — without leaving
your editor. This extension embeds the lacuna core
directly (no shelling out), so runs stream real, structured progress into the editor.
Features
Generate tests — right-click any source file, or use the editor title bar. Batch a whole
folder or a multi-selection.
Fix failing tests — right-click a test file, or use the inline CodeLens.
Coverage Gaps sidebar — every file below threshold / with no test, one click to generate.
Drag files onto it to queue them.
Coverage gutters — uncovered lines highlighted in the active editor from your LCOV report.
Live progress panel — a legible, append-only log of every phase (waiting → generating →
writing → running → retrying), streamed tokens, and which learned rules were used. "View Raw
Log" opens the full text in an Output channel.
Memory (Learned Rules) sidebar — browse the confidence-weighted rules Lacuna has learned,
sort by confidence / hit count, delete or flag ones that stop helping.
Settings form — generated from Lacuna's own config schema, writes .lacuna.json.
Trust, cost, and control
A generate/fix run makes real, metered API calls and writes files. This extension never hides
that:
A one-time disclosure before the first API call in a workspace.
A confirmation surface before every run — files, model, and worst-case request count.
A status-bar item present for the entire lifetime of any active run, with a Stop control.
A diff review of every changed file before you keep it. The shared mocks file is always
reviewed separately (it's imported by every test).
Auto Mode (per-workspace, opt-in) suppresses per-run confirmations — but never the mocks-file
review, and never environment changes. An unmissable status-bar indicator shows when it's on.
Getting started
Open a project with tests (Jest or Vitest).
Run Lacuna: Set Up (or open settings) to create .lacuna.json.
Run Lacuna: Set API Key — stored securely in the OS keychain via VS Code SecretStorage,
never written to .lacuna.json.
Right-click a source file → Generate Tests with Lacuna.
Configuration
All test-generation settings live in .lacuna.json (edit directly, or via the settings form).
A few editor-only preferences live in VS Code settings under lacuna.* (verbose streaming,
batch worker count, confirmation toggle).
