nestedMapExercise.java

import com.xxx.yyy.zzz.NestedMapBuilder;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;

import java.util.Map;

public class NestedMapBuilderTest {

    @Test
    public void testEmptyMap() {
        var input = Map.of();
        var expected = Map.of();
        var result = NestedMapBuilder.create(input);
        Assertions.assertEquals(expected, result);
    }

    @Test
    public void testAddSimpleMap() {
        var input = Map.of("hello", "test");
        var expected = Map.of("hello", "test");
        var result = NestedMapBuilder.create(input);
        Assertions.assertEquals(expected, result);
    }

    @Test
    public void testAddTwoNestedMap() {
        var input = Map.of("hello.test", 1);
        var expected = Map.of("hello", Map.of("test", 1));
        var result = NestedMapBuilder.create(input);
        Assertions.assertEquals(expected, result);
    }

    @Test
    public void testAddThreeNestedMap() {
        var input = Map.of("hello.test.hello", 1);
        var expected = Map.of("hello", Map.of("test", Map.of("hello", 1)));
        var result = NestedMapBuilder.create(input);
        Assertions.assertEquals(expected, result);
    }

    @Test
    public void testAddFourNestedMap() {
        var input = Map.of("hello.test.hello.cool", 1);
        var expected = Map.of("hello", Map.of("test", Map.of("hello", Map.of("cool", 1))));
        var result = NestedMapBuilder.create(input);
        Assertions.assertEquals(expected, result);
    }

    @Test
    public void testAddFiveNestedMap() {
        var input = Map.of("hello.test.hello.cool.really", "XXXX");
        var expected = Map.of("hello", Map.of("test", Map.of("hello", Map.of("cool", Map.of("really", "XXXX")))));
        var result = NestedMapBuilder.create(input);
        Assertions.assertEquals(expected, result);
    }
    @Test
    public void testAddSixNestedMap() {
        var input = Map.of("hello.test.hello.cool.really.deep", "XXXX");
        var expected = Map.of("hello", Map.of("test", Map.of("hello", Map.of("cool", Map.of("really", Map.of("deep","XXXX"))))));
        var result = NestedMapBuilder.create(input);
        Assertions.assertEquals(expected, result);
    }

}

//--------------------

public class NestedMapBuilder {
    public static <k, v> Map<k, v> create(Map<k, v> map) {        
        return map;
    }
}