updated the the output in error case, updated the tests of the CalculatorResourceTest

src/main/java/resources/CalculatorResource.java

@@ -37,17 +37,17 @@ public class CalculatorResource {
          * 1+2,
          * 10000+1000
          */
-        ;
-        if(expressionTrimmed.contains("+")) {
+        if (expressionTrimmed.matches("^\\d+(?:\\s*[+]\\s*\\d+)*$")) {
             result = sum(expressionTrimmed);
-        } else if(expressionTrimmed.matches("[0-9]+(\\.[0-9]+)?[-][0-9]+(\\.[0-9]+)?")) {
+        } else if (expressionTrimmed.matches("^\\d+(?:\\s*[-]\\s*\\d+)*$")) {
             result = subtraction(expressionTrimmed);
-        } else if(expressionTrimmed.matches("[0-9]+(\\.[0-9]+)?[*][0-9]+(\\.[0-9]+)?")) {
+        } else if (expressionTrimmed.matches("^\\d+(?:\\s*[*]\\s*\\d+)*$")) {
             result = multiplication(expressionTrimmed);
-        } else if(expressionTrimmed.matches("[0-9]+(\\.[0-9]+)?[/][0-9]+(\\.[0-9]+)?")) {
+        } else if (expressionTrimmed.matches("^\\d+(?:\\s*[/]\\s*\\d+)*$")) {
+
             result = division(expressionTrimmed);
         } else {
-            return "error";
+            return "Feil i uttrykket, prøv igjen";
         }
         return String.valueOf(result);
     }
@@ -63,7 +63,6 @@ public class CalculatorResource {
         for (String s : split) {
             result += Double.parseDouble(s);
         }
-
         return result;
     }
 

src/test/java/CalculatorResourceTest.java

@@ -10,17 +10,17 @@ public class CalculatorResourceTest{
     public void testCalculate(){
         CalculatorResource calculatorResource = new CalculatorResource();
 
-        String expression = "100+300";
-        assertEquals("400.0", calculatorResource.calculate(expression));
+        String expression = "100+300+100";
+        assertEquals("500.0", calculatorResource.calculate(expression));
 
-        expression = " 300 - 99 ";
-        assertEquals("201.0", calculatorResource.calculate(expression));
+        expression = "300 - 99 - 100";
+        assertEquals("101.0", calculatorResource.calculate(expression));
 
-        expression = "5*2";
-        assertEquals("10.0", calculatorResource.calculate(expression));
+        expression = "5*2*2";
+        assertEquals("20.0", calculatorResource.calculate(expression));
 
-        expression = "5/2";
-        assertEquals("2.5", calculatorResource.calculate(expression));
+        expression = "5/2/2";
+        assertEquals("1.25", calculatorResource.calculate(expression));
     }
 
     @Test
@@ -43,8 +43,8 @@ public class CalculatorResourceTest{
         String expression = "999-100";
         assertEquals(899, calculatorResource.subtraction(expression));
 
-        expression = "20-2";
-        assertEquals(18, calculatorResource.subtraction(expression));
+        expression = "20-2-8";
+        assertEquals(10, calculatorResource.subtraction(expression));
     }
 
     @Test
@@ -54,16 +54,16 @@ public class CalculatorResourceTest{
         String expression = "5*12";
         assertEquals(60, calculatorResource.multiplication(expression));
 
-        expression = "5*0";
-        assertEquals(0, calculatorResource.multiplication(expression));
+        expression = "5*2*2";
+        assertEquals(20, calculatorResource.multiplication(expression));
     }
 
     @Test
     public void testDivision() {
         CalculatorResource calculatorResource = new CalculatorResource();
 
-        String expression = "12/2";
-        assertEquals(6, calculatorResource.division(expression));
+        String expression = "12/2/2";
+        assertEquals(3, calculatorResource.division(expression));
 
         //test case for divide by 0
         expression = "12/0";