Michael Volz Inteview Challenge

src/main/java/com/github/archarithms/App.java

@@ -1,15 +1,68 @@
 package com.github.archarithms;
 
+import java.util.Date;
+import java.text.SimpleDateFormat;
 
 public class App
 {
+  /*
+   * Converts a string to title case, replacing non-alphanumeric characters with spaces
+   */
   public static String convertToTitleCase(final String inpStr)
   {
-    return inpStr;
+	//throw an exception if input string is null
+	if (inpStr==null) {
+		throw new IllegalArgumentException("Error: Input string must not be null");
+	}
+	//replace non-alphanumeric characters with spaces
+    String alphanumeric = inpStr.replaceAll("[^A-Za-z0-9]", " ");
+
+    //split into words
+    String[] words = alphanumeric.split(" ");
+
+    String result = "";
+
+    for (int i = 0; i < words.length; i++) {
+    	//capitalize the first letter, and make the rest of the letters lowercase
+    	result += Character.toUpperCase(words[i].charAt(0))
+    			+ words[i].substring(1).toLowerCase();
+    	//add a space after each word, except the last one
+    	if (i != words.length-1) result += " ";
+    }
+
+    return result;
   }
-
+
+  /*
+   * Converts a Unix epoch time in seconds and returns the "Month Day, Year" string representation"
+   */
   public static String convertUnixToDateString(final Long inpUnixSeconds)
   {
-    return String.valueOf(inpUnixSeconds);
+	//Throw an exception if the input is null
+	if (inpUnixSeconds == null) {
+		throw new IllegalArgumentException("Error: Input seconds must not be null");
+	}
+
+	//Create date object based on Unix milliseconds
+	Date date = new Date(inpUnixSeconds*1000);
+
+	//Create text format for the data
+	SimpleDateFormat format = new SimpleDateFormat("MMMM d, yyyy");
+
+	//return the formatted date
+	return format.format(date);
+  }
+
+  /*
+   * Gets the current time and returns the Month Day, Year string representation"
+   */
+  public static String convertUnixToDateString()
+  {
+	//Get the current time
+	Date date = new Date();
+	long current_ms = date.getTime();
+
+	//Call the matching function that takes the seconds argument
+	return convertUnixToDateString(current_ms/1000);
   }
 }

src/test/java/com/github/archarithms/test/DateStringTests.java

@@ -12,11 +12,6 @@
  */
 public class DateStringTests
 {
-
-    /*
-     * UNCOMMENT THE UNIT TESTS TO RUN THEM. FEEL FREE TO ADD MORE!
-     */
-
     /**
      * Test the testConvertUnixToDateString method
      */
@@ -25,12 +20,30 @@ public void testConvertUnixToDateString() {
         String testStr = "July 4, 2017";
         assertTrue(testStr.equals(App.convertUnixToDateString(1499144400L)));
     }
+
 
     /**
-     * Test the testNullCase method
+     * Test that a null value throws the custom exception
      */
     @Test
-    public void testNullCase() {
-        assertThrows(Exception.class, () -> App.convertUnixToDateString(null));
+    public void testNull() {
+        Exception e = assertThrows(IllegalArgumentException.class,
+        		() -> App.convertUnixToDateString(null),
+        		"msg");
+        assertTrue(e.getMessage().contains("Error: Input seconds must not be null"));
     }
+
+    /**
+     * Test that converting without passing an argument gives today's date.
+     * 
+     * NOTE: testStr needs to be properly set here to match today's date string
+     * in order to pass, so this test is commented out for now. To test, set the
+     * testStr properly and then uncomment.
+     */
+    /* @Test
+    public void testToday() {
+        String testStr = "January 31, 2021";
+        assertTrue(testStr.equals(App.convertUnixToDateString()));
+    } */
+
 }

src/test/java/com/github/archarithms/test/TitleCaseTests.java

@@ -1,9 +1,12 @@
 package com.github.archarithms.test;
 
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;
 
+import java.lang.IllegalArgumentException;
+
 import com.github.archarithms.App;
 
 /**
@@ -17,7 +20,7 @@ public class TitleCaseTests
      */
 
     /**
-     * Test the testConvertToTitleCase method
+     * Test an all-caps input with an underscore
      */
     @Test
     public void testConvertToTitleCase() {
@@ -26,7 +29,7 @@ public void testConvertToTitleCase() {
     }
 
     /**
-     * Test the testNumbers method
+     * Test an all-caps input with an underscore and number
      */
     @Test
     public void testNumbers() {
@@ -35,11 +38,31 @@ public void testNumbers() {
     }
 
     /**
-     * Test the testOtherChars method
+     * Test an all-caps input with a dash
      */
     @Test
     public void testOtherChars() {
         String testStr = "Truth Track";
         assertTrue(testStr.equals(App.convertToTitleCase("TRUTH-TRACK")));
     }
+
+    /**
+     * Test mix of characters with non-alphanumeric at the end
+     */
+    @Test
+    public void testComplexStr() {
+        String testStr = "Case Three Extra Chars";
+        assertTrue(testStr.equals(App.convertToTitleCase("CASE-THREE_extra[chars]///")));
+    }
+
+    /**
+     * Test that a null string throws the custom exception
+     */
+    @Test
+    public void testNull() {
+        Exception e = assertThrows(IllegalArgumentException.class,
+        		() -> App.convertToTitleCase(null),
+        		"msg");
+        assertTrue(e.getMessage().contains("Error: Input string must not be null"));
+    }
 }