[Poincare/tests] Added infinity symbols

poincare/Makefile

@@ -180,6 +180,7 @@ tests_src += $(addprefix poincare/test/,\
   function_solver.cpp\
   helper.cpp\
   helpers.cpp\
+  infinity.cpp \
   integer.cpp\
   layout.cpp\
   layout_cursor.cpp\

poincare/test/infinity.cpp

@@ -0,0 +1,7 @@
+#include "helper.h"
+
+QUIZ_CASE(poincare_infinity_symbol) {
+  assert_parsed_expression_simplify_to("inf", "∞");
+  assert_parsed_expression_simplify_to("oo", "∞");
+  assert_parsed_expression_simplify_to("∞", "∞");
+}