feat: handle regular expression match assertions if given var

cmake/Assertion.cmake

@@ -44,6 +44,9 @@ function(assert)
       list(GET ARGUMENTS 2 RIGHT_VALUE)
 
       if(OPERATOR STREQUAL MATCHES)
+        if(DEFINED "${LEFT_VALUE}")
+          set(LEFT_VALUE "${${LEFT_VALUE}}")
+        endif()
         set(MESSAGE "expected string '${LEFT_VALUE}'${NOT_WORD} to match '${RIGHT_VALUE}'")
       elseif(OPERATOR STREQUAL STREQUAL)
         set(MESSAGE "expected string '${LEFT_VALUE}'${NOT_WORD} to be equal to '${RIGHT_VALUE}'")

test/cmake/AssertionTest.cmake

@@ -72,18 +72,22 @@ function("Directory path assertions")
 endfunction()
 
 function("Regular expression match assertions")
-  assert("some string" MATCHES "so.*ing")
-  assert(NOT "some string" MATCHES "so.*other.*ing")
-
-  mock_message()
-    assert("some string" MATCHES "so.*other.*ing")
-  end_mock_message()
-  assert_message(FATAL_ERROR "expected string 'some string' to match 'so.*other.*ing'")
-
-  mock_message()
-    assert(NOT "some string" MATCHES "so.*ing")
-  end_mock_message()
-  assert_message(FATAL_ERROR "expected string 'some string' not to match 'so.*ing'")
+  set(STRING_VAR "some string")
+
+  foreach(VALUE STRING_VAR "${STRING_VAR}")
+    assert("${VALUE}" MATCHES "so.*ing")
+    assert(NOT "${VALUE}" MATCHES "so.*other.*ing")
+
+    mock_message()
+      assert(NOT "${VALUE}" MATCHES "so.*ing")
+    end_mock_message()
+    assert_message(FATAL_ERROR "expected string 'some string' not to match 'so.*ing'")
+
+    mock_message()
+      assert("${VALUE}" MATCHES "so.*other.*ing")
+    end_mock_message()
+    assert_message(FATAL_ERROR "expected string 'some string' to match 'so.*other.*ing'")
+  endforeach()
 endfunction()
 
 function("String equality assertions")