Merge remote-tracking branch 'upstream/master'

src/calc.cpp

@@ -35,6 +35,8 @@ int evaluate(const std::string &s) {
     case '^': change_stack_state(power,      stack); break;
     case '%': change_stack_state(modulo,   stack); break;
     case '0'...'9': stack.push(c - '0'); break;
+    default:
+      throw std::invalid_argument( "received unrecognized character" );
     }
   }
 

src/main.cpp

@@ -10,6 +10,12 @@ int main() {
 
   std::cout << "User input is \"" << user_input << "\"\n";
 
-  const int result{evaluate(user_input)};
-  std::cout << "Result is: " << result << '\n';
+  try{
+    const int result{evaluate(user_input)};
+    std::cout << "Result is: " << result << '\n';
+  } catch (const std::invalid_argument& e){
+    std::cout << "encountered invalid argument" << e.what() << "\n";
+    return -1;
+  }
+
 }

test/test.cpp

@@ -13,6 +13,26 @@ TEST_CASE( "pow function works", "[calc]") {
   REQUIRE_FALSE( evaluate("11^") == 2);
 }
 
+TEST_CASE( "basic addition", "[calc]"){
+  REQUIRE( evaluate("55+") == 10); 
+  REQUIRE( evaluate("34+") == 7);
+}
+
+TEST_CASE( "basic subtraction", "[calc]"){
+  REQUIRE( evaluate("55-") == 0); 
+  REQUIRE( evaluate("83-") == 5);
+}
+
+TEST_CASE( "basic multiplication", "[calc]"){
+  REQUIRE( evaluate("55*") == 25); 
+  REQUIRE( evaluate("36*") == 18);
+}
+
+TEST_CASE( "basic division", "[calc]"){
+  REQUIRE( evaluate("55/") == 1); 
+  REQUIRE( evaluate("93/") == 3);
+}
+
 TEST_CASE( "Test modulo function", "[calc]") {
   REQUIRE( evaluate("11%") == 0 );
   REQUIRE( evaluate("32%") == 1 );