[github-actions]

Summary

This PR adds comprehensive unit tests for the Permutation module, which had 0% test coverage previously. The module provides functions for creating and manipulating permutations used in linear algebra operations.

Problems Found

1. Permutation module had 0% test coverage - all permutation operations were untested
2. Overall project coverage was low at 4.83% (99/2047 lines)

Actions Taken

1. Created PermutationTests.fs with 39 comprehensive tests covering:

   • ofFreshArray/ofArray (9 tests): Creating permutations from arrays, validation, edge cases
   • sign (5 tests): Computing permutation sign (even/odd transpositions)
   • ofPairs (3 tests): Creating permutations from index mappings
   • swap (3 tests): Simple transposition operations
   • reversal (4 tests): Reversing index order
   • rotation (6 tests): Cyclic rotations with validation
   • identity (1 test): Identity permutation
   • inverse (6 tests): Computing and validating inverse permutations
   • Composition (2 tests): Testing algebraic properties

2. Updated FsMath.Tests.fsproj to include the new test file

3. All 171 tests pass (132 original + 39 new tests)

Test Coverage Results

Metric	Before	After	Change
Overall Line Coverage	4.83%	6.59%	+1.76%
Lines Covered	99/2047	135/2047	+36 lines
Total Tests	132	171	+39 tests
Permutation Module Coverage	0%	93.93%	+93.93%

Permutation Module Details

• Main module: 93.93% coverage (62/66 lines)
• All core functions tested with edge cases
• 4 uncovered lines are likely internal compiler-generated code

Replicating the Test Coverage Measurements

To replicate these measurements:

# Clean previous coverage
rm -rf ./coverage ./coverage-new

# Build the project
dotnet build

# Run tests with coverage (baseline on main)
git checkout main
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj \
  --no-build \
  --collect:"XPlat Code Coverage" \
  --results-directory ./coverage \
  -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=cobertura

# Extract baseline metrics
BASELINE_FILE=$(find ./coverage -name "coverage.cobertura.xml" | head -n 1)
grep -oP 'line-rate="\K[^"]*' "$BASELINE_FILE" | head -n 1  # Should show 0.0483
grep -oP 'lines-covered="\K[^"]*' "$BASELINE_FILE" | head -n 1  # Should show 99

# Run tests with coverage (on this branch)
git checkout test-coverage/permutation-module-20251011
dotnet build
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj \
  --no-build \
  --collect:"XPlat Code Coverage" \
  --results-directory ./coverage-new \
  -- DataCollectionRunSettings.DataCollectors.DataCollector.Configuration.Format=cobertura

# Extract new metrics
NEW_FILE=$(find ./coverage-new -name "coverage.cobertura.xml" | head -n 1)
grep -oP 'line-rate="\K[^"]*' "$NEW_FILE" | head -n 1  # Will show 0.0659
grep -oP 'lines-covered="\K[^"]*' "$NEW_FILE" | head -n 1  # Will show 135

# Verify test count increased
dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build | grep "Passed"  # Should show 171 tests

Possible Other Areas for Future Improvement

Based on the coverage report and dependency analysis, the following areas have 0% or very low coverage and could benefit from additional tests:

High Priority (Foundation - 0% coverage):

1. MatrixModule.fs (130 lines, 0% coverage) - Matrix utility functions
2. Algebra/Householder.fs (126 lines, 0% coverage) - Householder transformations for QR decomposition
3. Algebra/LinearAlgebra.fs (partial coverage) - QR, LU decomposition, solving systems
4. SIMDUtils.fs (0% coverage) - SIMD detection and utilities

Medium Priority (Advanced algorithms - 0% coverage):

5. Algebra/SVD.fs - Singular Value Decomposition
6. Algebra/EVD.fs - Eigenvalue Decomposition
7. SpecialFunctions/Gamma.fs (partial coverage) - Gamma function and related special functions

Recommendation: The next logical area would be MatrixModule.fs as it provides utility functions that other modules depend on, similar to how VectorModule was tested in PR #10.

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Execution Details (bash commands, web searches, web pages fetched)

Bash Commands Run:

• git checkout -b test-coverage/permutation-module-20251011
• dotnet build tests/FsMath.Tests/FsMath.Tests.fsproj
• dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build (multiple times)
• dotnet test tests/FsMath.Tests/FsMath.Tests.fsproj --no-build --collect:"XPlat Code Coverage" --results-directory ./coverage-new
• Coverage extraction and comparison using Python XML parsing
• git add tests/FsMath.Tests/PermutationTests.fs tests/FsMath.Tests/FsMath.Tests.fsproj
• git commit -m "Add comprehensive tests for Permutation module"

Web Searches:

None performed

Web Pages Fetched:

None fetched

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AI generated by Daily Test Coverage Improver

AI generated by Daily Test Coverage Improver