feat: kata/the-if-function (#633)

docs/README.md

@@ -1,7 +1,7 @@
 # Codewars Handbook ☕️🚀
 
 [![Views statistics +1 👀](https://img.shields.io/badge/dynamic/xml?color=success&label=views&query=//*[name()=%27text%27][3]&url=https://hits.seeyoufarm.com/api/count/incr/badge.svg?url=https%3A%2F%2Fgithub.com%2FParanoidUser%2Fcodewars-handbook)](https://hits.seeyoufarm.com/api/count/graph/dailyhits.svg?url=https://github.com/ParanoidUser/codewars-handbook)
-[![Completed kata 👌](https://img.shields.io/badge/completed%20kata-68.5%25-red.svg)](https://www.codewars.com/kata/search/java?xids=completed)
+[![Completed kata 👌](https://img.shields.io/badge/completed%20kata-68.6%25-red.svg)](https://www.codewars.com/kata/search/java?xids=completed)
 [![CI pipeline 🛠](https://img.shields.io/github/actions/workflow/status/ParanoidUser/codewars-handbook/build.yml?branch=main)](https://github.com/ParanoidUser/codewars-handbook/actions/workflows/build.yml)
 [![Quality gate 🔎](https://img.shields.io/sonar/alert_status/codewars-handbook?server=https%3A%2F%2Fsonarcloud.io)](https://sonarcloud.io/dashboard?id=codewars-handbook)
 [![Let's have a chat! 📞](https://img.shields.io/gitter/room/ParanoidUser/codewars-handbook?color=49c39e)](https://gitter.im/ParanoidUser/codewars-handbook)
@@ -25,7 +25,7 @@ slug.
 
 | [1 kyu](/kata/1-kyu/index.md) | [2 kyu](/kata/2-kyu/index.md) | [3 kyu](/kata/3-kyu/index.md) | [4 kyu](/kata/4-kyu/index.md) | [5 kyu](/kata/5-kyu/index.md) | [6 kyu](/kata/6-kyu/index.md) | [7 kyu](/kata/7-kyu/index.md) | [8 kyu](/kata/8-kyu/index.md) | [beta](/kata/beta/index.md) | [retired](/kata/retired/index.md) |
 |:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:---------------------------:|:---------------------------------:|
-| 0 | 1 | 2 | 26 | 48 | 430 | 577 | 211 | 56 | 79 |
+| 0 | 1 | 2 | 26 | 48 | 430 | 577 | 212 | 56 | 79 |
 
 **Note:** The source code is written in Java 17 and may use language features that are incompatible
 with Java 8, 11.

kata/8-kyu/index.md

@@ -205,6 +205,7 @@
 - [Switch it Up!](switch-it-up)
 # T
 - [The Feast of Many Beasts](the-feast-of-many-beasts)
+- [The 'if' function](the-if-function)
 - [The Wide-Mouthed frog!](the-wide-mouthed-frog)
 - [Thinkful - Logic Drills: Traffic light](thinkful-logic-drills-traffic-light)
 - [Thinkful - Number Drills: Blue and red marbles](thinkful-number-drills-blue-and-red-marbles)

kata/8-kyu/the-if-function/README.md

@@ -0,0 +1,13 @@
+# [The 'if' function](https://www.codewars.com/kata/the-if-function "https://www.codewars.com/kata/54147087d5c2ebe4f1000805")
+
+Create a function called `_if` which takes 3 arguments: a value `bool` and 2 functions (which do not take any
+parameters): `func1` and `func2`
+
+When `bool` is truthy, `func1` should be called, otherwise call the `func2`.
+
+### Example:
+
+```
+Kata._if(true, () -> System.out.println("true"), () -> System.out.println("false"));
+// prints "true" to the System out.
+```

kata/8-kyu/the-if-function/main/Kata.java

@@ -0,0 +1,5 @@
+interface Kata {
+  static void _if(Boolean bool, Runnable func1, Runnable func2) {
+    (bool != null && bool ? func1 : func2).run();
+  }
+}

kata/8-kyu/the-if-function/test/SolutionTest.java

@@ -0,0 +1,19 @@
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class SolutionTest {
+  @ParameterizedTest
+  @CsvSource(textBlock = """
+      true, true
+      false, false
+      , false
+      """)
+  void sample(Boolean bool, boolean expected) {
+    var actual = new AtomicBoolean(false);
+    Kata._if(bool, () -> actual.set(true), () -> actual.set(false));
+    assertEquals(expected, actual.get());
+  }
+}