Coverage Criteria

20.4.1. Minimum Coverage

Projects must meet the following minimum coverage thresholds for TQS certification.

Item	Minimum Threshold	Description
Lines	80%	Percentage of executed code lines
Branches	70%	Percentage of covered conditional branches (if/else, switch)
Functions	80%	Percentage of invoked functions
Statements	80%	Percentage of executed statements

• New projects must write tests to meet the thresholds from the outset.
• Existing projects should improve coverage incrementally; however, new code must meet the thresholds without exception.
• Tests that merely invoke functions without meaningful assertions are not recognized, even if coverage numbers appear high.

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20.4.2. Coverage Reports

Configure the coverage provider and report formats in vitest.config.ts.

import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    coverage: {
      provider: 'v8',
      reporter: ['text', 'html', 'lcov'],
      reportsDirectory: './coverage',
      include: ['src/**/*.{ts,vue}'],
      exclude: [
        'src/**/*.d.ts',
        'src/**/*.test.ts',
        'src/**/*.spec.ts',
        'src/**/index.ts',
        'src/types/**',
        'src/constants/**',
        'src/auto-generated/**',
      ],
    },
  },
})

Provider	Characteristics
v8	Built-in V8 engine coverage, fast execution, Vitest default
istanbul	Precise instrumentation, broad ecosystem compatibility

Report Format	Purpose
text	Immediate review in the terminal
html	Detailed per-file coverage review in the browser
lcov	Integration with CI tools and external services (SonarQube, Codecov, etc.)

• The TQS default coverage provider is v8.
• Generating all three report formats (text, html, lcov) is recommended.

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20.4.3. Exclusions

The following files are excluded from coverage measurement.

Exclusion Target	Reason
Type definition files (*.d.ts)	Not runtime code
Constant files (constants/)	Value definitions with no logic
Auto-generated code (auto-generated/)	Not manually maintained
Configuration files (vite.config.ts, vitest.config.ts, etc.)	Build/test configuration only
Re-export files (index.ts)	Perform only re-exports
Test files (*.test.ts, *.spec.ts)	Test code itself is not a coverage target

• Exclusion targets must be specified in the coverage.exclude array of vitest.config.ts.
• When new exclusion targets are added, the configuration file must be updated through team consensus.

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20.4.4. CI Integration

The CI pipeline must fail the build when coverage falls below the defined thresholds.

// vitest.config.ts
export default defineConfig({
  test: {
    coverage: {
      provider: 'v8',
      thresholds: {
        lines: 80,
        branches: 70,
        functions: 80,
        statements: 80,
      },
    },
  },
})

When thresholds are configured, Vitest returns a non-zero exit code if coverage falls below the specified values. The CI pipeline detects this and fails the build.

# CI pipeline example (GitHub Actions)
- name: Run tests with coverage
  run: yarn test:coverage

- name: Upload coverage report
  uses: actions/upload-artifact@v4
  with:
    name: coverage-report
    path: coverage/

• The thresholds values must match the minimum coverage criteria defined in Section 20.4.1.
• Coverage reports should be retained as CI artifacts to track history.
• Integrating with external services (Codecov, SonarQube, etc.) to visualize coverage trends is recommended.