test(tests): added test suite

The test suite is extensive. Note that LLMs were used to aid in the development of the test suite. All LLM generated code was manually reviewed.

tests/utils/laneemden/formatting.cpp

@@ -0,0 +1,71 @@
+#include <array>
+#include <format>
+#include <iterator>
+#include <string>
+
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/matchers/catch_matchers_string.hpp>
+
+#include "serif/utils/laneemden/solution.hpp"
+
+namespace {
+    namespace laneemden = serif::utils::laneemden;
+    constexpr laneemden::Sample sample{.xi = 2.0, .theta = 0.5, .derivative = -0.25};
+
+    /** @brief Use distinct profile and surface values so selection forwarding is observable. */
+    [[nodiscard]] laneemden::Solution example_solution() {
+        return {
+            .n = 1.0,
+            .samples = {{.xi = 0.0, .theta = 1.0, .derivative = 0.0}, sample},
+            .surface = laneemden::Sample{.xi = 3.0, .theta = 0.0, .derivative = -0.5}
+        };
+    }
+}
+
+TEST_CASE("Lane Emden sample formatting selects complete or individual values", "[laneemden][formatting]") {
+    CHECK(std::format("{}", sample) == "(ξ=2, θ=0.5, dθ/dξ=-0.25)");
+    CHECK(std::format("{:}", sample) == std::format("{}", sample));
+    CHECK(std::format("{:all}", sample) == std::format("{}", sample));
+    CHECK(std::format("{:xi}", sample) == "2");
+    CHECK(std::format("{:theta}", sample) == "0.5");
+    CHECK(std::format("{:derivative}", sample) == "-0.25");
+    CHECK(std::format("{1:theta} / {0:xi}", sample, sample) == "0.5 / 2");
+    CHECK(std::format("{{{:xi}}}", sample) == "{2}");
+}
+
+TEST_CASE("Lane Emden solution formatting forwards selection to its profile and surface", "[laneemden][formatting]") {
+    const auto solution = example_solution();
+    CHECK(std::format("{}", solution) == "Solution(n=1, samples=[(ξ=0, θ=1, dθ/dξ=0), (ξ=2, θ=0.5, dθ/dξ=-0.25)], surface=(ξ=3, θ=0, dθ/dξ=-0.5))");
+    CHECK(std::format("{:}", solution) == std::format("{}", solution));
+    CHECK(std::format("{:all}", solution) == std::format("{}", solution));
+    CHECK(std::format("{:xi}", solution) == "Solution(n=1, samples=[0, 2], surface=3)");
+    CHECK(std::format("{:theta}", solution) == "Solution(n=1, samples=[1, 0.5], surface=0)");
+    CHECK(std::format("{:derivative}", solution) == "Solution(n=1, samples=[0, -0.25], surface=-0.5)");
+    const laneemden::Solution empty{.n = 5.0, .samples = {}, .surface = {}};
+    CHECK(std::format("{}", empty) == "Solution(n=5, samples=[], surface=none)");
+    CHECK(std::format("{:theta}", empty) == "Solution(n=5, samples=[], surface=none)");
+}
+
+TEST_CASE("Lane Emden formatters preserve surrounding output and independent selectors", "[laneemden][formatting]") {
+    const auto solution = example_solution();
+    const std::string expected = "prefix Solution(n=1, samples=[1, 0.5], surface=0) | 2 | Solution(n=1, samples=[0, -0.25], surface=-0.5) suffix";
+    std::string appended = "prefix ";
+    std::format_to(std::back_inserter(appended), "{:theta} | {:xi} | {:derivative} suffix", solution, sample, solution);
+    CHECK(appended == expected);
+    std::array<char, 512> buffer{};
+    const auto end = std::format_to(buffer.data(), "prefix {:theta} | {:xi} | {:derivative} suffix", solution, sample, solution);
+    CHECK(std::string(buffer.data(), end) == expected);
+}
+
+TEST_CASE("Lane Emden formatters reject unsupported selectors through the central error helper", "[laneemden][formatting]") {
+    const auto solution = example_solution();
+    for (const std::string specifier : {"radius", "xi,theta", "theta ", ".2f", "theta:.2f"}) {
+        CAPTURE(specifier);
+        const std::string format = "{:" + specifier + "}";
+        CHECK_THROWS_AS(std::vformat(format, std::make_format_args(sample)), std::format_error);
+        CHECK_THROWS_AS(std::vformat(format, std::make_format_args(solution)), std::format_error);
+        CHECK_THROWS_WITH(std::vformat(format, std::make_format_args(sample)), Catch::Matchers::ContainsSubstring("Unknown Lane–Emden sample selector"));
+    }
+    CHECK_THROWS_AS(std::vformat("{:xi", std::make_format_args(sample)), std::format_error);
+    CHECK_THROWS_AS(std::vformat("{:theta", std::make_format_args(solution)), std::format_error);
+}