Add tests for the to_string operation

Author: Thomas Kiley

unit/Makefile

@@ -87,6 +87,7 @@ SRC += analyses/ai/ai.cpp \
        util/interval/multiply.cpp \
        util/interval/shift.cpp \
        util/interval/subtract.cpp \
+       util/interval/to_string.cpp \
        util/interval_constraint.cpp \
        util/interval_union.cpp \
        util/irep.cpp \

unit/util/interval/to_string.cpp

@@ -0,0 +1,52 @@
+/*******************************************************************\
+ Module: Unit tests for variable/sensitivity/abstract_object::merge
+ Author: DiffBlue Limited
+\*******************************************************************/
+
+#include <testing-utils/use_catch.h>
+#include <util/arith_tools.h>
+#include <util/interval.h>
+#include <util/std_types.h>
+
+TEST_CASE("interval::to_string", "[core][analyses][interval]")
+{
+  const signedbv_typet signed_int_type(32);
+  const unsignedbv_typet unsigned_int_type(32);
+  const auto signed_expr = [&](const int value) {
+    return from_integer(value, signed_int_type);
+  };
+  const auto unsigned_expr = [&](const int value) {
+    return from_integer(value, unsigned_int_type);
+  };
+
+  REQUIRE(constant_interval_exprt(signed_expr(1)).to_string() == "[1,1]");
+  REQUIRE(
+    constant_interval_exprt(signed_expr(1), signed_expr(2)).to_string() ==
+    "[1,2]");
+
+  REQUIRE(
+    constant_interval_exprt::top(signed_int_type).to_string() == "[MIN,MAX]");
+
+  REQUIRE(
+    constant_interval_exprt::top(unsigned_int_type).to_string() == "[0,MAX]");
+
+  REQUIRE(
+    constant_interval_exprt(signed_expr(1), max_exprt{signed_int_type})
+      .to_string() == "[1,MAX]");
+
+  REQUIRE(
+    constant_interval_exprt(min_exprt{signed_int_type}, signed_expr(1))
+      .to_string() == "[MIN,1]");
+  REQUIRE(
+    constant_interval_exprt(min_exprt{unsigned_int_type}, unsigned_expr(1))
+      .to_string() == "[0,1]");
+
+  REQUIRE(
+    constant_interval_exprt(
+      min_exprt{signed_int_type}, max_exprt{signed_int_type})
+      .to_string() == "[MIN,MAX]");
+  REQUIRE(
+    constant_interval_exprt(
+      min_exprt{unsigned_int_type}, max_exprt{unsigned_int_type})
+      .to_string() == "[0,MAX]");
+}