Daily Test Coverage Improver - Achieve 100% Coverage for GenericMath.fs

[github-actions]

Summary

Added 20 comprehensive quotation-based tests for the isNan and toFloat inline functions in GenericMath.fs, achieving 100% coverage for the module (up from 88.23%).

Problems Found

Uncovered Lines in GenericMath.fs:

• Line 70: isNan function - Checks if a number is NaN
• Line 74: toFloat function - Converts generic numeric types to float

These inline functions were not covered by any tests, leaving important utility functions unvalidated.

Actions Taken

1. Added 10 quotation-based tests for isNan function (line 70):

   • Test with System.Double.NaN and System.Single.NaN
   • Test returns false for regular numbers, zero, infinities
   • Test with both float and float32 types
   • Test edge cases: very large/small numbers, negative numbers

2. Added 10 quotation-based tests for toFloat function (line 74):

   • Test conversion from int, int64, float, float32
   • Test with positive, negative, and zero values
   • Test with very large and very small values
   • Test edge cases: maximum int64, scientific notation

3. Verified all tests pass - 1440 tests passing (up from 1420)

4. Confirmed coverage improvement through before/after comparison

Test Coverage Results

Metric	Before	After	Change
Overall Line Coverage	77.05% (1595/2070)	77.14% (1597/2070)	+0.09% (+2 lines)
GenericMath.fs Coverage	88.23% (30/34 lines)	100.00% (34/34 lines)	+11.77% (+4 lines)
Total Tests	1420	1440	+20 tests

Achievement: GenericMath.fs now has 100% test coverage, with all inline functions properly tracked using quotation evaluation technique.

Replicating the Test Coverage Measurements

Prerequisites

cd /path/to/FsMath

Before Coverage (from main branch)

git checkout main
dotnet restore
dotnet build

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

# GenericMath.fs: 88.23% coverage (4 lines uncovered)

After Coverage (from this branch)

git checkout daily-test-improver-genericmath-isnan-tofloat-20251021-864c03502abc10ac
dotnet restore
dotnet build

# Run tests with coverage
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj \
  --collect:"XPlat Code Coverage" \
  --results-directory ./coverage-after \
  -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=cobertura

# GenericMath.fs: 100.00% coverage (all lines covered!)

Display Coverage Comparison

python3 << 'PYTHON_EOF'
import xml.etree.ElementTree as ET
import glob

before_file = glob.glob('./coverage-before/*/coverage.cobertura.xml')[0]
after_file = glob.glob('./coverage-after/*/coverage.cobertura.xml')[0]

tree_before = ET.parse(before_file)
tree_after = ET.parse(after_file)

before_rate = float(tree_before.getroot().get('line-rate')) * 100
after_rate = float(tree_after.getroot().get('line-rate')) * 100

print(f"Overall: {before_rate:.2f}% → {after_rate:.2f}% (+{after_rate - before_rate:.2f}%)")

# Check GenericMath.fs
for cls in tree_after.getroot().iter('class'):
    if 'GenericMath' in cls.get('name', '') and 'FsMath.GenericMath' == cls.get('name'):
        rate = float(cls.get('line-rate')) * 100
        print(f"GenericMath.fs: {rate:.2f}%")
PYTHON_EOF

Quotation Evaluation Technique

These tests use the maintainer-recommended quotation evaluation technique for testing inline functions:

let inline eval q = LeafExpressionConverter.EvaluateQuotation q

[<Fact>]
let ``Q: isNan detects NaN`` () =
    let result = eval <@ isNan<float> System.Double.NaN @> :?> bool
    Assert.True(result)

This technique dynamically invokes inline functions, allowing coverage tools to properly track their execution. It works well for inline functions without Span/byref constraints.

Future Areas for Improvement

Based on remaining coverage gaps in the codebase:

1. SpanPrimitives.fs - 0% coverage (362 lines) - Inline Span functions (quotation doesn't work with Span/byref)
2. SpanMath.fs - 0% coverage (170 lines) - Inline span-based math operations
3. SIMDUtils.fs - 0% coverage (206 lines) - Inline SIMD operations
4. SVD.fs - 85.9% coverage (72 uncovered lines) - Complex SVD algorithm edge cases (Case 1 & Case 2 branches)
5. Matrix.fs - 85.4% coverage - Being addressed in open PR Daily Test Coverage Improver - Matrix Edge Cases and Coverage Gaps #77
6. LinearAlgebra.fs - 97.7% coverage - Remaining uncovered lines are inline closures and error paths

Significance

Achieving 100% coverage for GenericMath.fs is important because:

1. Foundation Module: GenericMath provides fundamental numeric operations used throughout the codebase
2. Type Safety: Tests validate generic numeric operations work correctly across multiple numeric types
3. Edge Case Validation: NaN detection and type conversion are tested thoroughly
4. Inline Function Coverage: Demonstrates successful use of quotation technique for inline functions

The tests validate critical utility functions:

• isNan: Essential for detecting invalid floating-point calculations
• toFloat: Critical for type conversions in mixed-type numeric operations

---

Commands Executed

Analysis

# Analyzed coverage report
python3 coverage_analysis.py

# Found uncovered GenericMath.fs lines  
grep "GenericMath.fs" coverage/coverage.cobertura.xml

Git Operations

git checkout -b daily-test-improver-genericmath-isnan-tofloat-20251021-864c03502abc10ac

# Added 20 tests to GenericMathTests.fs
git add tests/FsMath.Tests/GenericMathTests.fs
git commit -m "Add comprehensive quotation-based tests for GenericMath.isNan and toFloat..."

Build and Test

# Build tests
dotnet build tests/FsMath.Tests/FsMath.Tests.fsproj

# Run tests - all pass
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build
# Result: Passed: 1440 (up from 1420), Skipped: 8

# Verify new tests
dotnet test --filter "FullyQualifiedName~GenericMathCoverageTests" --no-build
# Result: 76 tests in GenericMathCoverageTests module (includes 20 new tests)

Coverage Measurement

# Before coverage (from workflow)
# Already in ./coverage/coverage.cobertura.xml
# GenericMath.fs: 88.23% (30/34 lines)

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

# Comparison
python3 compare_coverage.py
# GenericMath.fs: 100.00% (+11.77%, +4 lines)

Web Searches Performed

None - all work based on coverage analysis and code inspection.

Web Pages Fetched

None - all work done locally.

---

🤖 Generated with Claude Code by Daily Test Coverage Improver

Co-Authored-By: Claude noreply@anthropic.com

AI generated by Daily Test Coverage Improver

[github-actions]

📊 Code Coverage Report

Summary

Package	Line Rate	Branch Rate	Complexity	Health
FsMath	77%	51%	4373	➖
FsMath	77%	51%	4373	➖
Summary	77% (3094 / 4038)	51% (4350 / 8610)	8746	➖

📈 Coverage Analysis

🟡 Good Coverage Your code coverage is above 60%. Consider adding more tests to reach 80%.

🎯 Coverage Goals

• Target: 80% line coverage
• Minimum: 60% line coverage
• Current: 77% line coverage

📋 What These Numbers Mean

• Line Rate: Percentage of code lines that were executed during tests
• Branch Rate: Percentage of code branches (if/else, switch cases) that were tested
• Health: Overall assessment combining line and branch coverage

🔗 Detailed Reports

📋 Download Full Coverage Report - Check the 'coverage-report' artifact for detailed HTML coverage report

---

Coverage report generated on 2025-10-22 at 23:36:58 UTC