Add Progmasoft Catch3 property testing and build support0.1.0

Introduce deterministic property execution, built-in generators, shrinking, replayable seeds, and a separate Progmasoft-owned header API while preserving Catch2 compatibility targets and the C++14 engine baseline.

Add Bazel, Meson, Xmake, and Premake integration and tests alongside the existing CMake build. Replace Linux-only workflow coverage with Windows and macOS jobs and document the Catch2/Catch3 distinction.

1 files changed, 82 insertions, 0 deletions

diff --git a/src/Progmasoft/Catch3/Generators/Integer.hpp b/src/Progmasoft/Catch3/Generators/Integer.hpp
new file mode 100644
index 00000000..2a50525e
--- /dev/null
+++ b/src/Progmasoft/Catch3/Generators/Integer.hpp
@@ -0,0 +1,82 @@
+// Copyright (c) 2026 Progmasoft.
+// SPDX-License-Identifier: MPL-2.0 WITH AdditionRef-Progmasoft-Exception-1.1
+#pragma once
+
+#include <Progmasoft/Catch3/Generator.hpp>
+
+#include <algorithm>
+#include <concepts>
+#include <limits>
+#include <type_traits>
+
+namespace Progmasoft::Catch3 {
+    namespace Detail {
+
+        template <std::integral IntegerType>
+        requires( !std::same_as<IntegerType, bool> )
+            [[nodiscard]] std::vector<IntegerType> ShrinkInteger(
+                IntegerType value, IntegerType minimum, IntegerType maximum ) {
+            std::vector<IntegerType> candidates;
+            const auto addCandidate = [&]( IntegerType candidate ) {
+                if ( candidate < minimum || candidate > maximum ||
+                     candidate == value ||
+                     std::ranges::find( candidates, candidate ) !=
+                         candidates.end() ) {
+                    return;
+                }
+                candidates.push_back( candidate );
+            };
+
+            if ( value == 0 ) { return candidates; }
+
+            // First try the conventional simplest value, then halve toward it.
+            // The adjacent value at the end lets the runner find boundary
+            // counterexamples (for example, the first failing integer in a
+            // threshold property).
+            if ( minimum <= 0 && maximum >= 0 ) { addCandidate( 0 ); }
+
+            IntegerType smaller = value;
+            while ( smaller != 0 ) {
+                smaller = static_cast<IntegerType>( smaller / 2 );
+                if ( smaller == 0 ) { break; }
+                addCandidate( smaller );
+            }
+
+            if ( value > 0 ) {
+                if ( value > minimum ) {
+                    addCandidate( static_cast<IntegerType>( value - 1 ) );
+                }
+                if ( minimum > 0 ) { addCandidate( minimum ); }
+            } else {
+                if ( value < maximum ) {
+                    addCandidate( static_cast<IntegerType>( value + 1 ) );
+                }
+                if ( maximum < 0 ) { addCandidate( maximum ); }
+            }
+            return candidates;
+        }
+
+    } // namespace Detail
+
+    /// Generates integers over the inclusive range and shrinks toward simple
+    /// values.
+    template <std::integral IntegerType>
+    requires( !std::same_as<IntegerType, bool> )
+        [[nodiscard]] Generator<IntegerType> Integer(
+            IntegerType minimum = std::numeric_limits<IntegerType>::lowest(),
+            IntegerType maximum = std::numeric_limits<IntegerType>::max() ) {
+        if ( minimum > maximum ) {
+            throw std::invalid_argument(
+                "Integer requires minimum <= maximum" );
+        }
+
+        return MakeGenerator<IntegerType>(
+            [minimum, maximum]( Random& random ) {
+                return random.Between( minimum, maximum );
+            },
+            [minimum, maximum]( const IntegerType& value ) {
+                return Detail::ShrinkInteger( value, minimum, maximum );
+            } );
+    }
+
+} // namespace Progmasoft::Catch3