DNDS Core Unit Tests

Overview

The DNDSR project uses the doctest (v2.4.11) framework for C++ unit testing. Test sources live under test/cpp/DNDS/ and are built only when DNDS_BUILD_TESTS=ON.

Every MPI-aware test is registered with CTest at four process counts (np = 1, 2, 4, 8) so that correctness under parallel execution is verified automatically.

Building and Running

# Configure with tests
cmake -B build -DDNDS_BUILD_TESTS=ON

# Build all test executables at once
cmake --build build -t dnds_unit_tests -j8

# Run every registered test (serial + MPI np=1,2,4,8)
ctest --test-dir build -R dnds_ --output-on-failure

# Run a single test suite
ctest --test-dir build -R dnds_mpi_np2 --output-on-failure

# Run a single executable directly
mpirun -np 4 ./build/test/cpp/dnds_test_array_transformer

Naming Conventions

CMake target

CTest names

Source file

dnds_test_array

dnds_array

test_Array.cpp

dnds_test_mpi

dnds_mpi_np{1,2,4}

test_MPI.cpp

dnds_test_array_transformer

dnds_array_transformer_np{1,2,4}

test_ArrayTransformer.cpp

dnds_test_array_derived

dnds_array_derived_np{1,2,4}

test_ArrayDerived.cpp

dnds_test_array_dof

dnds_array_dof_np{1,2,4}

test_ArrayDOF.cpp

dnds_test_index_mapping

dnds_index_mapping_np{1,2,4}

test_IndexMapping.cpp

dnds_test_serializer

dnds_serializer_np{1,2,4}

test_Serializer.cpp

dnds_test_permutation_transfer

dnds_permutation_transfer_np{1,2,4}

test_PermutationTransfer.cpp

Note on POSIX index() Ambiguity

Because doctest includes <cstring> which transitively pulls in the POSIX index() function from <strings.h>, the bare name index is ambiguous when using namespace DNDS; is active. All test files therefore qualify the DNDS type aliases as DNDS::index, DNDS::real, and DNDS::rowsize in declarations.

Array Tests (test_Array.cpp)

See also: test_Array.cpp

Serial-only tests covering every DNDS::Array data layout:

  • TABLE_StaticFixed — Array<real, 3>: compile-time fixed row size. Validates Size(), RowSize(), element read/write via operator() and operator[], DataSize(), DataSizeBytes().

  • TABLE_Fixed — Array<real, DynamicSize>: runtime-uniform row size.

  • TABLE_StaticMax — Array<real, NonUniformSize, 4>: per-row variable sizes up to a compile-time maximum.

  • TABLE_Max — Array<real, NonUniformSize, DynamicSize>: per-row variable sizes up to a runtime maximum.

  • CSR — Array<real, NonUniformSize>: compressed sparse row. Tests lambda-based Resize, Compress/Decompress round-trips, ResizeRow in decompressed mode.

  • Clone and copy — clone(), CopyData(), copy constructor, SwapData() independence checks.

  • Edge cases — zero-size arrays, single-element arrays, CSR rows of length zero.

  • Serialization — JSON round-trip for TABLE_Fixed, CSR, and TABLE_StaticFixed via DNDS::Serializer::SerializerJSON.

  • Signature — GetArraySignature(), ParseArraySignatureTuple(), ArraySignatureIsCompatible().

  • Hash — identical arrays produce equal hashes; modified arrays differ.

MPI Wrapper Tests (test_MPI.cpp)

See also: test_MPI.cpp

Run at np = 1, 2, 4, 8. All expected values are formulated in terms of mpi.size so they hold for any rank count.

  • MPIInfo basics — setWorld(), field validity, equality.

  • Allreduce — MPI_SUM and MPI_MAX for real and index; AllreduceOneReal, AllreduceOneIndex.

  • Scan — inclusive prefix sum.

  • Allgather — single and multi-element.

  • Bcast — from rank 0 and from last rank.

  • Barrier — returns MPI_SUCCESS.

  • BasicType_To_MPIIntType — scalar types, std::array, Eigen::Matrix.

  • CommStrategy — get/set HIndexed/InSituPack.

  • Alltoall — single and multi-element exchange.

ArrayTransformer Tests (test_ArrayTransformer.cpp)

See also: test_ArrayTransformer.cpp

Exercises ghost (halo) communication at np = 1, 2, 4, 8.

  • ParArray basics — createGlobalMapping(), globalSize(), AssertConsistent().

  • Pull – TABLE_StaticFixed — 100 elements/rank, pulls first 5 from each remote rank, verifies ghost data.

  • Pull – TABLE_Fixed — complete replication pull.

  • Pull – CSR — variable row sizes, verifies both data and row sizes in ghosts.

  • Pull – std::array elements — std::array<real,9> as the element type.

  • Persistent pull — initPersistentPull / startPersistentPull / waitPersistentPull, then modify father and re-pull.

  • BorrowGGIndexing — second array shares the ghost mapping of the first, independently pulls correct data.

  • Push — write to son, pushOnce(), verify father received values.

ArrayDerived Tests (test_ArrayDerived.cpp)

See also: test_ArrayDerived.cpp

Covers every derived array type at np = 1, 2, 4, 8.

  • ArrayAdjacency — basics (resize, row resize, compress, operator[], rowPtr()), ghost communication, clone, fixed-size variant.

  • ArrayEigenVector — basics (static and dynamic sizes), ghost communication.

  • ArrayEigenMatrix — static sizes, dynamic sizes, NonUniform rows, ghost communication.

  • ArrayEigenMatrixBatch — InitializeWriteRow, BatchSize, operator(), ghost communication.

  • ArrayEigenUniMatrixBatch — static and dynamic sizes, ResizeBatch.

ArrayDOF Tests (test_ArrayDOF.cpp)

See also: test_ArrayDOF.cpp

Tests every vector-space operation on DNDS::ArrayDof at np = 1, 2, 4, 8. All MPI-global reductions (norm2, dot, min, max, sum, componentWiseNorm1) use rank-aware expected values.

  • setConstant (scalar and matrix)

  • operator+= (scalar, array, matrix)

  • operator-=, operator*= (scalar, element-wise, matrix)

  • operator/=

  • addTo

  • norm2, norm2(other) (L2 distance)

  • dot

  • min, max, sum

  • componentWiseNorm1, componentWiseNorm1(other)

  • operator= (value copy), clone (deep copy)

  • scalar-array multiply (ArrayDof<N,1> *= ArrayDof<1,1>)

  • identity: dot(x, x) == norm2(x)^2

IndexMapping Tests (test_IndexMapping.cpp)

See also: test_IndexMapping.cpp

Tests global/local index mapping at np = 1, 2, 4, 8.

  • GlobalOffsetsMapping — uniform distribution, non-uniform distribution, search() for first/last/middle/out-of-range indices.

  • OffsetAscendIndexMapping — pull-based construction, searchInMain, searchInGhost, searchInAllGhost, search, search_indexAppend, operator() reverse mapping, empty ghost set.

Serializer Tests (test_Serializer.cpp)

See also: test_Serializer.cpp

Round-trip write/read verification at np = 1, 2, 4, 8.

  • SerializerJSON scalar — WriteInt/ReadInt, WriteIndex/ReadIndex, WriteReal/ReadReal, WriteString/ReadString.

  • SerializerJSON vector — WriteRealVector, WriteIndexVector, WriteRowsizeVector.

  • SerializerJSON uint8 — with and without base64 codec.

  • SerializerJSON paths — CreatePath, GoToPath, GetCurrentPath, ListCurrentPath.

  • SerializerJSON pointer dedup — shared pointer written twice resolves to same object on read.

  • SerializerH5 scalar — WriteInt/ReadInt, WriteIndex/ReadIndex, WriteReal/ReadReal, WriteString/ReadString (HDF5 attributes).

  • SerializerH5 vector — WriteRealVector, WriteIndexVector with explicit ArrayGlobalOffset; read with ArrayGlobalOffset_Unknown auto-detection from the rank_offsets companion dataset.

  • SerializerH5 distributed vector — non-uniform per-rank sizes, read with both ArrayGlobalOffset_Unknown and explicit offset.

  • SerializerH5 uint8 — two-pass read (nullptr size query, then actual read with offset from pass 1).

  • SerializerH5 paths — GoToPath, GetCurrentPath, ListCurrentPath (groups materialized by writing content).

  • SerializerH5 string — fixed-length HDF5 string attributes.

PermutationTransfer Tests (test_PermutationTransfer.cpp)

See also: test_PermutationTransfer.cpp

Tests for DNDS::PermutationTransfer, the MPI primitive underlying the distributed entity reordering framework (see Distributed Reorder Design for the full architecture). Runs at np = 1, 2, 4, 8.

Construction

  • fromLocalPermutation reverse — builds from an old2new local permutation (reverse), verifies isLocalOnly == true, newGlobalIndices reflect the permutation, and transferRows places source data at the permuted slot.

  • fromLocalPermutation identity — no-op permutation; data unchanged.

  • fromPartition all-local — partition where every entity stays on its current rank; validates isLocalOnly == true via MPI_Allreduce.

  • fromPartition round-robin — cross-rank partition (i % size); validates counts received per rank and that all tags arrive uniquely.

buildLookup and resolve

  • buildLookup resolve — construct lookup from a transfer; resolve() for local globals returns correct new globals; resolve(UnInitIndex) passes through.

  • Distributed buildLookup cross-rank — with non-empty pullSet, resolve() correctly maps off-rank old globals to their new globals after ghost-pull.

transferRows

  • CSR local permutation — variable-row-size CSR array, reverse permutation preserves every row’s size and contents at the permuted slot.

  • Distributed transfer tag tracking — each entry tagged with a unique TAG_BASE + globalIdx sentinel; after round-robin transfer, all received tags are within the valid range, unique on each rank, and the total count across ranks matches the original global size.