Add Unity-based unit test infrastructure (Phase 1 — 117 tests) (#177)

Introduced new system for unit tests based on the Unity framework.

Added tests for some of the simple functions in four different files.

tests/CMakeLists.txt

@@ -0,0 +1,103 @@
+# tests/CMakeLists.txt
+# Unity-based unit tests for tbaMUD
+#
+# Each test executable is built from:
+#   vendor/unity/unity.c   — test framework
+#   test_stubs.c           — weak-symbol stubs for all unresolved mud globals
+#   src/<module>.c         — the source file(s) under test
+#   test_<name>.c          — the test file itself
+#
+# Only the source files being tested are compiled — in particular comm.c
+# (which contains main()) is never included.
+
+cmake_minimum_required(VERSION 3.12)
+
+enable_testing()
+
+# ---------------------------------------------------------------------------
+# Common settings shared by all test targets
+# ---------------------------------------------------------------------------
+
+set(UNITY_SRC  ${CMAKE_CURRENT_SOURCE_DIR}/vendor/unity/unity.c)
+set(STUBS_SRC  ${CMAKE_CURRENT_SOURCE_DIR}/test_stubs.c)
+
+set(MUD_SRCDIR ${CMAKE_SOURCE_DIR}/src)
+
+# Include paths: mud source dir for conf.h / structs.h etc.,
+# CMake binary dir for the generated conf.h (cmake builds place it there),
+# and the Unity header dir.
+set(TEST_INCLUDES
+    ${MUD_SRCDIR}
+    ${CMAKE_BINARY_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/vendor/unity
+)
+
+# Suppress warnings that fire in generated stubs / vendored code and in the
+# mud sources when compiled outside their normal full-build context.
+set(TEST_CFLAGS)
+if(CMAKE_C_COMPILER_ID MATCHES "^(GNU|Clang|AppleClang)$")
+    list(APPEND TEST_CFLAGS
+        -Wno-unused-parameter
+        -Wno-unused-function
+        -Wno-unused-variable
+    )
+endif()
+
+# Helper macro: add_mud_test(name SRC1 [SRC2 …])
+# Creates an executable, registers it with CTest.
+macro(add_mud_test TEST_NAME)
+    add_executable(${TEST_NAME}
+        ${UNITY_SRC}
+        ${STUBS_SRC}
+        ${ARGN}
+    )
+    target_include_directories(${TEST_NAME} PRIVATE ${TEST_INCLUDES})
+    target_compile_options(${TEST_NAME} PRIVATE ${TEST_CFLAGS})
+    add_test(NAME ${TEST_NAME} COMMAND ${TEST_NAME})
+endmacro()
+
+# ---------------------------------------------------------------------------
+# test_utils  — covers src/utils.c
+# ---------------------------------------------------------------------------
+add_mud_test(test_utils
+    ${MUD_SRCDIR}/utils.c
+    ${MUD_SRCDIR}/random.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/test_utils.c
+)
+
+# ---------------------------------------------------------------------------
+# test_random — covers src/random.c and rand_number/dice in src/utils.c
+# ---------------------------------------------------------------------------
+add_mud_test(test_random
+    ${MUD_SRCDIR}/random.c
+    ${MUD_SRCDIR}/utils.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/test_random.c
+)
+
+# ---------------------------------------------------------------------------
+# test_interpreter — covers string helpers in src/interpreter.c
+# ---------------------------------------------------------------------------
+add_mud_test(test_interpreter
+    ${MUD_SRCDIR}/interpreter.c
+    ${MUD_SRCDIR}/utils.c
+    ${MUD_SRCDIR}/random.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/test_interpreter.c
+)
+
+# crypt() is referenced from interpreter.c (nanny password hashing).
+# Reuse the crypt library detected by the top-level build when one is needed;
+# on platforms where crypt() is provided by libc, no extra link library is
+# required.
+if(CRYPT_LIBRARY)
+    target_link_libraries(test_interpreter PRIVATE ${CRYPT_LIBRARY})
+endif()
+
+# ---------------------------------------------------------------------------
+# test_class — covers src/class.c
+# ---------------------------------------------------------------------------
+add_mud_test(test_class
+    ${MUD_SRCDIR}/class.c
+    ${MUD_SRCDIR}/utils.c
+    ${MUD_SRCDIR}/random.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/test_class.c
+)