Adding utilities for checking types in unit tests

Author: thk123

unit/testing-utils/Makefile

@@ -2,6 +2,7 @@ SRC = \
   c_to_expr.cpp \
   load_java_class.cpp \
   require_expr.cpp \
+  require_type.cpp \
   # Empty last line (please keep above list sorted!)
 
 INCLUDES = -I .. -I . -I ../../src

unit/testing-utils/require_type.cpp

@@ -0,0 +1,51 @@
+/*******************************************************************\
+
+ Module: Unit test utilities
+
+ Author: DiffBlue Limited. All rights reserved.
+
+\*******************************************************************/
+
+#include "require_type.h"
+
+#include <testing-utils/catch.hpp>
+#include <util/base_type.h>
+
+/// Checks a type is a pointer type optionally with a specific subtype
+/// \param type: The type to check
+/// \param subtype: An optional subtype. If provided, checks the subtype of the
+///   pointer is this.
+/// \return A cast to pointer_typet version of type
+pointer_typet require_type::require_pointer(
+  const typet &type,
+  const optionalt<typet> &subtype)
+{
+  REQUIRE(type.id() == ID_pointer);
+  const pointer_typet &pointer = to_pointer_type(type);
+
+  if(subtype)
+  {
+    // TODO: use base_type_eq
+    REQUIRE(pointer.subtype() == subtype.value());
+  }
+  return pointer;
+}
+
+/// Checks a struct like type has a component with a specific name
+/// \param struct_type: The structure that should have the component
+/// \param component_name: The name of the component
+/// \return The component with the specified name
+struct_union_typet::componentt require_type::require_component(
+  const struct_typet &struct_type,
+  const irep_idt &component_name)
+{
+  const auto &componet = std::find_if(
+    struct_type.components().begin(),
+    struct_type.components().end(),
+    [&component_name](const struct_union_typet::componentt &component) {
+      return component.get_name() == component_name;
+    });
+
+  REQUIRE(componet != struct_type.components().end());
+  return *componet;
+}

unit/testing-utils/require_type.h

@@ -0,0 +1,32 @@
+/*******************************************************************\
+
+ Module: Unit test utilities
+
+ Author: DiffBlue Limited. All rights reserved.
+
+\*******************************************************************/
+
+/// \file
+/// Helper functions for requiring specific types
+/// If the type is of the wrong type, throw a CATCH exception
+/// Also checks associated properties and returns a casted version of the
+/// expression.
+
+#ifndef CPROVER_TESTING_UTILS_REQUIRE_TYPE_H
+#define CPROVER_TESTING_UTILS_REQUIRE_TYPE_H
+
+#include <util/optional.h>
+#include <util/std_types.h>
+
+// NOLINTNEXTLINE(readability/namespace)
+namespace require_type
+{
+pointer_typet
+require_pointer(const typet &type, const optionalt<typet> &subtype);
+
+struct_typet::componentt require_component(
+  const struct_typet &struct_type,
+  const irep_idt &component_name);
+}
+
+#endif