Demo v8 Coverage Issues

This repository has been initialized to highlight issues about the @vitest/coverage-v8 coverage provider.

This repository uses

• Vue 3 (v3.3.4)
• TypeScript (v5.0.2)
• Vite (v4.4.0)
• Vitest (v0.33.0)
• @vitest/coverage-c8 (v0.33.0)
• @vitest/coverage-v8 (v0.33.0)

Architecture

The component file src/components/coverage-test-component.vue, importing src/components/coverage-test-component.ts, is being tested from the tests/coverage-test-component.spec.js test file.

The vite.config.ts contains all coverage informations.

The following command is used to launch tests.

$ npm run test:unit

Observed results - V8

Using the V8 coverage provider in vite.config.ts, the following coverage is being observed.

 % Coverage report from v8
-------------------|---------|----------|---------|---------|-------------------
File               | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
-------------------|---------|----------|---------|---------|-------------------
All files          |   95.45 |    83.33 |     100 |   95.45 |                   
 ...t-component.ts |   95.45 |    83.33 |     100 |   95.45 | 43-45             
-------------------|---------|----------|---------|---------|-------------------

=============================== Coverage summary ==============================
Statements   : 95.45% ( 63/66 )
Branches     : 83.33% ( 5/6 )
Functions    : 100% ( 3/3 )
Lines        : 95.45% ( 63/66 )
================================================================================

Prompting wrong lines not being covered, while lines actually not covered are flagged as correct.

coverage/lcov-report/index.html shows the following :

Expected results - C8

Using the c8 coverage provider in vite.config.ts, the following coverage is being observed.

% Coverage report from c8
-------------------|---------|----------|---------|---------|-------------------
File               | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
-------------------|---------|----------|---------|---------|-------------------
All files          |   96.96 |       75 |     100 |   96.96 |                   
 ...t-component.ts |   96.96 |       75 |     100 |   96.96 | 62-63             
-------------------|---------|----------|---------|---------|-------------------

=============================== Coverage summary ===============================
Statements   : 96.96% ( 64/66 )
Branches     : 75% ( 3/4 )
Functions    : 100% ( 3/3 )
Lines        : 96.96% ( 64/66 )
================================================================================

Lines not covered are displayed correctly.

coverage/lcov-report/index.html shows the following :