package com.codility.tasks.invert;

import com.codility.tasks.invert.Inverter;
import org.junit.Assert;
import static org.junit.Assert.*;
import org.junit.Test;

public class InverterTest {

    @Test
    public void invertNullShouldReturnEmptyString() {
        /// Arrange
        String expectedValue = "";
        String passedValue = null;

        /// Act
        String result = Inverter.invert(passedValue);

        /// Assert
        assertEquals(expectedValue, result);
    }

    @Test
    public void invertEmptyShouldReturnEmptyString() {
        /// Arrange
        String expectedValue = "";
        String passedValue = "";

        /// Act
        String result = Inverter.invert(passedValue);

        /// Assert
        assertEquals(expectedValue, result);
    }

    @Test
    public void invertOneLetterStringShouldReturnThisSameObject() {
        /// Arrange
        String passedValue = "a";

        /// Act
        String result = Inverter.invert(passedValue);

        /// Assert
        assertSame(result, passedValue);
    }


    @Test
    public void invertCBAShouldReturnABC() {
        /// Arrange
        String passedValue = "CBA";
        String expectedValue = "ABC";

        /// Act
        String result = Inverter.invert(passedValue);

        /// Assert
        assertEquals(result, expectedValue);
    }

}