Add --shuffle and --seed options for randomizing test execution order#531
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Add --shuffle and --seed options for randomizing test execution order#531
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Implements issue #530: Add command-line options to randomize test execution order within each test suite to help detect hidden test dependencies. Changes: - Add --shuffle flag to enable random test ordering - Add --seed=N option to specify random seed (0=time-based, implies --shuffle) - Implement Fisher-Yates shuffle algorithm in TestSuite - Tests are shuffled within each suite, preserving suite boundaries - Add comprehensive unit tests (Test_TestSuite_Shuffle.F90) - Add integration tests (ShuffleIntegrationTests.pf, test_shuffle.sh) All tests pass, including reproducibility with same seed and verification that shuffle actually changes test order.
Extract helper subroutines to improve code readability: - initialize_random_seed(): Handles seed initialization logic - swap_tests(): Encapsulates test swapping with move_alloc This reduces maximum nesting level from 4 to 2 and makes each subroutine have a single, clear responsibility.
Replace complex array-based shuffling with simpler index-based approach: - Shuffle integer indices array instead of Test objects - Build new vector by accessing tests in shuffled index order - Eliminates TestReference type, temp array allocations, and swap_tests() This is cleaner, more efficient (no polymorphic object copying), and easier to understand.
- Use array constructor indices = [(i, i=1, n)] instead of explicit loop - Remove superfluous explicit deallocate() for allocatable arrays - Eliminate else clause by setting default seed_array first - Replace magic number 1000 with 997 (prime) and add explanatory comment
When user_seed==0, just use Fortran's default random_seed() initialization instead of manually constructing a time-based seed. The compiler's default is perfectly adequate for non-reproducible randomization.
mathomp4
approved these changes
Mar 10, 2026
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Summary
Implements #530: Add command-line options to randomize test execution order within each test suite to help detect hidden test dependencies.
Changes
Core Implementation:
--shuffleflag to enable random test ordering--seed=Noption to specify random seed (0=time-based, implies --shuffle)Modified Files:
src/funit/core/TestSuite.F90: Added shuffle functionality withset_shuffle()andshuffle_tests()methodssrc/funit/FUnit.F90: Added CLI argument parsing for --shuffle and --seed optionsNew Tests:
tests/funit-core/Test_TestSuite_Shuffle.F90: Comprehensive unit tests (6 test cases)tests/funit-core/ShuffleIntegrationTests.pf: Integration test suitetests/funit-core/test_shuffle.sh: Shell script for command-line testingTesting
All tests pass:
Usage Examples