feat: kata/simple-calculator (#826)

* docs: kata description

* feat: kata/simple-calculator

* refactor: no division by zero error guaranteed in input

---------

Co-authored-by: ParanoidUser <5120290+ParanoidUser@users.noreply.github.com>

Author: github-actions[bot]

kata/8-kyu/index.md

@@ -180,6 +180,7 @@
 - [Rock Paper Scissors!](rock-paper-scissors "5672a98bdbdd995fad00000f")
 - [Sentence Smash](sentence-smash "53dc23c68a0c93699800041d")
 - [Short Long Short](short-long-short "50654ddff44f800200000007")
+- [simple calculator ](simple-calculator "5810085c533d69f4980001cf")
 - [Simple Fun #1: Seats in Theater](simple-fun-number-1-seats-in-theater "588417e576933b0ec9000045")
 - [Simple multiplication](simple-multiplication "583710ccaa6717322c000105")
 - [Simple validation of a username with regex](simple-validation-of-a-username-with-regex "56a3f08aa9a6cc9b75000023")

kata/8-kyu/simple-calculator/README.md

@@ -0,0 +1,19 @@
+# [Simple calculator ](https://www.codewars.com/kata/simple-calculator "https://www.codewars.com/kata/5810085c533d69f4980001cf")
+
+You are required to create a simple calculator that returns the result of addition, subtraction, multiplication or division of two numbers.
+
+Your function will accept three arguments:  
+ - The first and second argument should be numbers.  
+- The third argument should represent a sign indicating the operation to perform on these two numbers.
+
+If the sign is not a valid sign, throw an IllegalArgumentException (Java) or ArgumentException (C#).
+
+# Example:
+
+```
+arguments: 1, 2, "+"
+should return 3
+
+arguments: 1, 2, "&"
+should throw an IllegalArgumentException (Java) or ArgumentException (C#)
+```

kata/8-kyu/simple-calculator/main/Calculator.java

@@ -0,0 +1,11 @@
+interface Calculator {
+  static double calculate(double a, double b, String op) {
+    return switch (op) {
+      case "+" -> a + b;
+      case "-" -> a - b;
+      case "*" -> a * b;
+      case "/" -> a / b;
+      default -> throw new IllegalArgumentException();
+    };
+  }
+}

kata/8-kyu/simple-calculator/test/SolutionTest.java

@@ -0,0 +1,30 @@
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class SolutionTest {
+  @ParameterizedTest
+  @CsvSource(textBlock = """
+      1, 2, +, 3
+      6, 2, +, 8
+      4, 3, -, 1
+      5, 5, *, 25
+      5, 4, /, 1.25
+      """)
+  void basicOperation(double a, double b, String op, double expected) {
+    assertEquals(expected, Calculator.calculate(a, b, op), 1e-3);
+  }
+
+  @ParameterizedTest
+  @CsvSource(textBlock = """
+      6, 2, &
+      3, 5, \\
+      5, 5, =
+      6, 3, '\t'
+      """)
+  void unsupportedOperation(double a, double b, String op) {
+    assertThrows(IllegalArgumentException.class, () -> Calculator.calculate(a, b, op));
+  }
+}