Daily Test Coverage Improver - VectorOps @ Operator Tests (100% VectorOpsSymbols Coverage)

[github-actions]

Summary

Added 10 comprehensive tests for the @ operator in VectorOps to achieve 100% coverage for the VectorOpsSymbols class. Used both regular and quotation-based testing techniques to ensure inline function coverage tracking.

Problems Found

• VectorOpsSymbols @ operator (line 46) - Not covered by any tests
• The @ operator calls Power.Invoke despite the comment on line 47 saying "// Dot product ( @ )"
• This appears to be a mismatch between the comment and implementation (possible bug or outdated comment)

Actions Taken

1. Added 5 regular tests to VectorOpsTests.fs for the @ operator

   • Basic power operation (squares, cubes)
   • Fractional powers (square roots)
   • Negative powers (reciprocals)
   • Zero power (returns ones)
   • Various edge cases

2. Added 5 quotation-based tests to VectorOpsCoverageTests.fs using the maintainer-recommended technique

   • Same test scenarios as above
   • Uses F# quotation evaluation (evalQ <@ v @ 2.0 @>) to track inline function execution
   • This technique is necessary because inline functions are not tracked by coverage tools otherwise

3. Verified all tests pass - 1357 tests passing (up from 1347)

4. Confirmed coverage improvement through before/after comparison

Test Coverage Results

Metric	Before	After	Change
Overall Line Coverage	77.33% (1583/2047)	77.38% (1584/2047)	+0.05% (+1 line)
VectorOpsSymbols Coverage	83.33% (5/6 lines)	100.00% (6/6 lines)	+16.67% (+1 line)
@ operator (line 46)	NOT COVERED (0 hits)	COVERED (5 hits)	New coverage
Total Tests	1347	1357	+10 tests

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

# VectorOpsSymbols: 83.33%, Line 46: NOT COVERED

After Coverage (from this branch)

git checkout daily-test-improver-svd-edge-cases-20251013-971ac4b5bb0e6ade
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

# VectorOpsSymbols: 100.00%, Line 46: COVERED (5 hits)

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', 0)) * 100
after_rate = float(tree_after.getroot().get('line-rate', 0)) * 100

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

for cls in tree_after.getroot().iter('class'):
    if cls.get('name') == 'FsMath.VectorOpsSymbols':
        rate = float(cls.get('line-rate', 0)) * 100
        print(f"VectorOpsSymbols: {rate:.2f}%")
PYTHON_EOF

About the @ Operator

The @ operator is defined in VectorOps.fs line 46 as:

let inline ( @ ) a b = Power.Invoke(a, b)
// Dot product ( @ )

Current Behavior: The operator performs element-wise power operations (e.g., [2.0; 3.0] @ 2.0 = [4.0; 9.0])

Comment Says: "Dot product ( @ )"

This mismatch may indicate:

1. A bug where Dot.Invoke should be called instead of Power.Invoke
2. An outdated comment that should be updated to say "Power ( @ )"

Tests validate current behavior (Power operations) to establish a baseline. If maintainers determine this is a bug, the operator implementation can be fixed and these tests will catch the regression.

Future Areas for Improvement

Based on remaining coverage gaps:

1. SpanPrimitives.fs - 0% coverage (366 lines) - Inline Span functions (quotation doesn't work with Span/byref)
2. SpanMath.fs - 0% coverage (160 lines) - Inline span-based math
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 - 88.7% coverage - Being addressed in PR Daily Test Coverage Improver - Matrix Edge Case Tests #67
6. Permutation.fs - 92.3% coverage - Being addressed in PR Daily Test Coverage Improver - Fix PermutationTests Incomplete Assertions #68

Note: This PR demonstrates successful use of the quotation evaluation technique recommended by maintainers for testing inline functions. The technique works well for non-Span/byref inline functions and successfully tracks coverage.

---

Commands Executed

Analysis

# Read coverage report
python3 coverage_analysis.py

# Check VectorOpsSymbols coverage details
grep -A 10 "VectorOpsSymbols" coverage/coverage.cobertura.xml

# Find uncovered line 46
python3 find_uncovered_vectorops.py

Git Operations

git checkout -b daily-test-improver-svd-edge-cases-20251013-971ac4b5bb0e6ade
# Added tests to VectorOpsTests.fs and VectorOpsCoverageTests.fs
git add tests/FsMath.Tests/VectorOpsTests.fs tests/FsMath.Tests/VectorOpsCoverageTests.fs
git commit -m "Add comprehensive tests for @ operator..."

Build and Test

dotnet build tests/FsMath.Tests/FsMath.Tests.fsproj
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build
# Result: Passed: 1357 (up from 1347), Skipped: 8

Coverage Measurement

# Before coverage (from main)
# Already in ./coverage/coverage.cobertura.xml
# VectorOpsSymbols: 83.33%

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

# Comparison
python3 compare_coverage.py
# VectorOpsSymbols: 100.00% (+16.67%)

Web Searches Performed

None - the issue was identified through coverage analysis and code inspection.

Web Pages Fetched

None - all work done through local code analysis.

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🤖 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%	49%	4409	➖
FsMath	77%	49%	4409	➖
Summary	77% (3076 / 3992)	49% (4274 / 8686)	8818	➖

📈 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

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Coverage report generated on 2025-10-13 at 20:39:39 UTC