tests: initial dense tensor unit tests (#164)

- Added tests for constructors, add, sub, uminus, smul.
- Iterator test is work in progress with TODO where value needs to be checked. Need to confirm correct API here with Sam.
- Remaining tests are placeholder TEST_Fs to wrap before PR.
- tensor_fixture.h methods extended. `generic_tensor` replaced with more meaningful `make_ones_tensor`. Complementary functions `make_ns_tensor` used in new tests as LAL was only checking values where all coefficients were 1, but new tests check broader values. `make_tensor` takes a generic function for initialising each coefficient.
- `test_free_tensor` and `test_lie` updated with new fixture.

algebra/src/CMakeLists.txt

@@ -7,8 +7,11 @@ add_subdirectory(libalgebra_lite_internal)
 if (ROUGHPY_BUILD_TESTS)
 
     add_executable(test_algebra
-        test_lie.cpp
+        tensor_fixture.cpp
+        tensor_fixture.h
+        test_dense_tensor.cpp
         test_free_tensor.cpp
+        test_lie.cpp
     )
 
     target_link_libraries(test_algebra PRIVATE RoughPy::Algebra GTest::gtest)

algebra/src/tensor_fixture.cpp

@@ -0,0 +1,48 @@
+// Copyright (c) 2024 RoughPy Developers. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+// this list of conditions and the following disclaimer in the documentation
+// and/or other materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors
+// may be used to endorse or promote products derived from this software without
+// specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#include "tensor_fixture.h"
+
+namespace rpy {
+namespace algebra {
+namespace testing {
+
+void TensorFixture::SetUp()
+{
+    auto rational_poly_tpo = scalars::ScalarType::of<devices::rational_poly_scalar>();
+    if (!rational_poly_tpo) {
+        GTEST_FAIL();
+    }
+
+    rational_poly_tp = *rational_poly_tpo;
+    context = rpy::algebra::get_context(width, depth, rational_poly_tp);
+}
+
+} // namespace testing
+} // namespace algebra
+} // namespace rpy

algebra/src/tensor_fixture.h

@@ -0,0 +1,117 @@
+// Copyright (c) 2024 RoughPy Developers. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+// this list of conditions and the following disclaimer in the documentation
+// and/or other materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors
+// may be used to endorse or promote products derived from this software without
+// specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef ROUGHPY_ALGEBRA_SRC_TENSOR_FIXTURE_H
+#define ROUGHPY_ALGEBRA_SRC_TENSOR_FIXTURE_H
+
+#include <gtest/gtest.h>
+
+#include "roughpy/core/ranges.h"
+#include "roughpy/core/types.h"
+#include "roughpy/algebra/context.h"
+#include "roughpy/scalars/scalar_types.h"
+
+namespace rpy {
+namespace algebra {
+namespace testing {
+
+//! FIXME docs
+//!
+class TensorFixture : public ::testing::Test
+{
+protected:
+    const deg_t width = 2;
+    const deg_t depth = 5;
+    const scalars::ScalarType* rational_poly_tp;
+    rpy::algebra::context_pointer context;
+
+protected:
+    void SetUp() override;
+
+public:
+    //! Create free tensor with all coeffs 1 of width and depth and given char
+    RPY_NO_DISCARD FreeTensor make_ones_tensor(
+        char indeterminate_char
+    ) const
+    {
+        FreeTensor result = make_tensor([indeterminate_char](size_t i) {
+            auto key = scalars::indeterminate_type(indeterminate_char, i);
+            auto coeff = scalars::rational_poly_scalar(key, scalars::rational_scalar_type(1));
+            return coeff;
+        });
+        return result;
+    }
+
+    //! Create free tensor with all coeffs N of width and depth and given char
+    RPY_NO_DISCARD FreeTensor make_ns_tensor(
+        char indeterminate_char,
+        scalars::rational_scalar_type n
+    ) const
+    {
+        FreeTensor result = make_tensor([indeterminate_char, n](size_t i) {
+            auto key = scalars::indeterminate_type(indeterminate_char, i);
+            auto coeff = scalars::rational_poly_scalar(key, n);
+            return coeff;
+        });
+        return result;
+    }
+
+    //! Create free tensor with each coeff constructed from make_coeff_fn
+    //! defaulting to default tensor data size. Lambda signature is:
+    //!     make_coeff_fn(size_t index) -> scalars::rational_poly_scalar
+    template <typename MakeCoeffFn>
+    RPY_NO_DISCARD FreeTensor make_tensor(
+        MakeCoeffFn&& make_coeff_fn
+    ) const
+    {
+        using namespace rpy::scalars;
+
+        // Construct and allocate a rational polynomial
+        VectorConstructionData cons_data{
+            KeyScalarArray(rational_poly_tp),
+            VectorType::Dense
+        };
+        const dimn_t size = context->tensor_size(depth);
+        cons_data.data.allocate_scalars(size);
+
+        // Delegate the construction of each basis with coefficient
+        auto slice = cons_data.data.as_mut_slice<rational_poly_scalar>();
+        for (auto&& [i, coeff] : views::enumerate(slice)) {
+            coeff = make_coeff_fn(i);
+        }
+
+        FreeTensor result = context->construct_free_tensor(cons_data);
+        return result;
+    }
+};
+
+} // namespace testing
+} // namespace algebra
+} // namespace rpy
+
+#endif // ROUGHPY_ALGEBRA_SRC_TENSOR_FIXTURE_H