Daily Test Coverage Improver - Householder quotation-based tests

[github-actions]

Summary

Added 18 comprehensive quotation-based tests for the Householder module using F# quotation evaluation technique. This approach ensures that inline functions (Householder.create, Householder.applyLeft, Householder.applyRight) are properly tracked by coverage tools, addressing the maintainer's suggestion from discussion #5.

Test Coverage Results

Metric	Before	After	Change
Overall Line Coverage	32.09% (657/2047)	35.12% (719/2047)	+3.03% (+62 lines)
Householder.fs Coverage	0.00%	98.41%	+98.41%
Total Tests	767 (765+2 skipped)	784 (782+2 skipped)	+17 tests

Changes Made

New Test Module: HouseholderQuotationTests

Added a new test module in tests/FsMath.Tests/LinearAlgebra.fs with:

1. Quotation evaluation helper: Uses Microsoft.FSharp.Linq.RuntimeHelpers.LeafExpressionConverter.EvaluateQuotation to invoke inline functions in a way that coverage tools can track

2. 18 new tests covering:

   • Householder.create function (8 tests):
     • Simple vector cases (e.g., [3, 0, 0], [4, 3])
     • Edge cases (single element, zero tail, negative first element)
     • Various vector sizes and value ranges
   • Householder.applyLeft function (5 tests):
     • Identity transformation (zero tau)
     • Column transformations
     • Orthogonal transformation preservation
     • Row offset handling
   • Householder.applyRight function (4 tests):
     • Identity transformation
     • Row transformations
     • Norm preservation
     • Column offset handling
   • Householder mathematical properties (1 test):
     • Reflection involution property (applying twice returns original)

Technical Approach

The quotation evaluation technique wraps inline function calls in F# quotations (<@ ... @>) and evaluates them at runtime. For void-returning functions like applyLeft and applyRight, the quotation is wrapped in a lambda: <@ fun () -> Householder.applyLeft(...) @>. This ensures the inline code is executed and tracked by the coverage tool.

Replicating the Test Coverage Measurements

Install Dependencies & Build

dotnet restore
dotnet build

Run Tests

dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj

Expected: 784 tests passing (782 passed, 2 skipped)

Generate Coverage Reports

Before changes (baseline on main branch):

git checkout main
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj \
  --collect:"XPlat Code Coverage" \
  --results-directory ./coverage-before \
  -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=cobertura

After changes (on this PR branch):

git checkout daily-test-improver-householder-quotation-20251012-375e265fa6845a2f
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj \
  --collect:"XPlat Code Coverage" \
  --results-directory ./coverage-after \
  -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=cobertura

Compare coverage:

# Extract coverage percentages from the XML files
grep -oP 'line-rate="\K[^"]*' coverage-before/*/coverage.cobertura.xml | head -n1 | awk '{printf "Before: %.2f%%\n", $1 * 100}'
grep -oP 'line-rate="\K[^"]*' coverage-after/*/coverage.cobertura.xml | head -n1 | awk '{printf "After: %.2f%%\n", $1 * 100}'

Future Work Recommendations

Based on the coverage analysis, the following areas have low coverage and could benefit from similar quotation-based testing:

1. VectorOps.fs (0% coverage) - Many inline vector operations
2. SpanPrimitives.fs (0% coverage) - SIMD-aware span operations
3. SpanMath.fs (0% coverage) - Span-based math operations
4. SIMDUtils.fs (0% coverage) - SIMD utility functions
5. Vector.fs (0% coverage) - Core vector type operations
6. LinearAlgebra.fs - Several inline functions showing 0% despite existing tests

The quotation evaluation technique demonstrated here can be applied to these modules to significantly improve coverage tracking.

Notes

• All 784 tests pass successfully
• No linting errors introduced
• Follows existing test organization and naming conventions
• Uses the assertion helpers from AssertHelpers.fs
• Maintains consistency with existing Householder tests (which remain unchanged)

---

Commands Run

# Branch creation
git checkout -b daily-test-improver-householder-quotation-20251012-375e265fa6845a2f

# Build and test
dotnet restore
dotnet build --no-restore
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build

# Coverage collection (before)
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --collect:"XPlat Code Coverage" --results-directory ./coverage -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=cobertura

# Code modifications
# (edited tests/FsMath.Tests/LinearAlgebra.fs)

# Build and test again
dotnet build --no-restore
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build

# Coverage collection (after)
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build --collect:"XPlat Code Coverage" --results-directory ./coverage-new -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=cobertura

# Commit
git add tests/FsMath.Tests/LinearAlgebra.fs
git commit -m "Add quotation-based tests for Householder inline functions"

Web Searches Performed

None

Web Pages Fetched

None

---

🤖 Generated with Claude Code

AI generated by Daily Test Coverage Improver