Code Refactoring

Activity 1.20.1.

There is a copy of the following code block in an interactive mode that you can modify and compile. Your task is to improve the code’s style as an expert would view it, while ensuring its behavior remains unchanged. You may run your refactored code to verify that it still passes all test cases.

🔗

public class Internship { 
	public static String checkInternshipEligibility(int schoolYear, double GPA, boolean hasWorkExperience) {
		if (schoolYear >= 4) {
			if (GPA >= 3.5) {
		    	if (hasWorkExperience) {
		        	return "Eligible";
		    	} else {
		        	return "You only need some work experience!";
		    	}
			}
		}
		return "Not eligible";
	}
}

public class Internship {
	public static String checkInternshipEligibility(int schoolYear, double GPA, boolean hasWorkExperience) {
		if (schoolYear >= 4) {
			if (GPA >= 3.5) {
		    	if (hasWorkExperience) {
		        	return "Eligible";
		    	} else {
		        	return "You only need some work experience!";
		    	}
			}
		}
		return "Not eligible";
	}
}
====
import static org.junit.Assert.*;
		import org.junit.Test;
		import java.io.*;
		import org.junit.Before;
		import org.junit.After;
		import java.io.ByteArrayOutputStream;
		import java.io.PrintStream;

public class RunestoneTests extends CodeTestHelper {

public RunestoneTests() {
          super("Internship");
      }

// Test for eligibility based on everything
      @Test
      public void testEligibleBySchoolYear() throws IOException {
          Object[] args = {4,3.5,true};  // Arguments for the method, year and gpa
          String output = getMethodOutput("checkInternshipEligibility", args);
          String expect = "Eligible";
          
          boolean passed = getResults(expect, output, "checkInternshipEligibility(4,3.5,true)");
          assertTrue(passed);
      }

// Test for not eligibility based on GPA
      @Test
      public void testEligibleByGpa() throws IOException {
          Object[] args = {4, 2.5,true};  // Arguments for the method
          String output = getMethodOutput("checkInternshipEligibility", args);
          String expect = "Not eligible";
          
          boolean passed = getResults(expect, output, "checkInternshipEligibility(4, 2.5, true)");
          assertTrue(passed);
      }

// Test for not eligible based on year
      @Test
      public void testNotEligibleForYear() throws IOException {
          Object[] args = {2, 3.7, true};  // Arguments for the method
          String output = getMethodOutput("checkInternshipEligibility", args);
          String expect = "Not eligible";
          
          boolean passed = getResults(expect, output, "checkInternshipEligibility(2, 3.7, true)");
          assertTrue(passed);
      }

// Test for not eligibility based on workExperience
      @Test
      public void testNotEligibleByExperience() throws IOException {
          Object[] args = {5, 3.5, false};  // Arguments for the method
          String output = getMethodOutput("checkInternshipEligibility", args);
          String expect = "You only need some work experience!";
          
          boolean passed = getResults(expect, output, "checkInternshipEligibility(5, 3.5, false)");
          assertTrue(passed);
      }

// Test for not eligibility based on GPA and lower school year
      @Test
      public void testEligibleByGpaAndYear() throws IOException {
          Object[] args = {2, 3.2, true};  // Arguments for the method
          String output = getMethodOutput("checkInternshipEligibility", args);
          String expect = "Not eligible";
          
          boolean passed = getResults(expect, output, "checkInternshipEligibility(2, 3.2, true)");
          assertTrue(passed);
      }
      // Test for not eligibility based on GPA and not Experience 
	@Test  
      public void testEligibleByGpaAndExperience() throws IOException {
          Object[] args = {4, 3.2, false};  // Arguments for the method
          String output = getMethodOutput("checkInternshipEligibility", args);
          String expect = "Not eligible";
          
          boolean passed = getResults(expect, output, "checkInternshipEligibility(4, 3.2, false)");
          assertTrue(passed);
      }
      // Test for not eligibility based on year and not Experience 
      @Test  
      public void testEligibleByExperienceAndYear() throws IOException {
          Object[] args = {3, 3.5, false};  // Arguments for the method
          String output = getMethodOutput("checkInternshipEligibility", args);
          String expect = "Not eligible";
          
          boolean passed = getResults(expect, output, "checkInternshipEligibility(3, 3.5, false)");
          assertTrue(passed);
      }
      
    }

🔗

Activity 1.20.2.

Which of the following code blocks is the most similar to your final refactored code for the previous question?

🔗

public class Internship {
  public static String checkInternshipEligibility(int schoolYear, double GPA, boolean hasWorkExperience) {
    if (schoolYear >= 4 && GPA >= 3.5 && hasWorkExperience) {
      return "Eligible";
    } else {
      return "You only need some work experience!";
    }
    return "Not eligible";
  }
}

This code does not compile because the last return statement is unreachable (it never executes). Copy the original code into the interactive section and try refactoring it again.

public class Internship {
  public static String checkInternshipEligibility(int schoolYear, double GPA, boolean hasWorkExperience) {
    if (schoolYear >= 4 && GPA >= 3.5 && hasWorkExperience) {
      return "Eligible";
    }
    return "Not eligible";
  }
}

The code doesn’t have the same functionality with the original one. Copy the original code into the interactive section and try refactoring it again.

public class Internship {
  public static String checkInternshipEligibility(int schoolYear, double GPA, boolean hasWorkExperience) {
    if (schoolYear < 4 || GPA < 3.5) {
      return "Not eligible";
    }
    if (hasWorkExperience) {
      return "Eligible";
    }
    return "You only need some work experience!";
  }
}

You did it correctly!

public class Internship {
  public static String checkInternshipEligibility(int schoolYear, double GPA, boolean hasWorkExperience) {
    if (schoolYear >= 4 && GPA >= 3.5) {
      if (hasWorkExperience) {
        return "Eligible";
      } else {
        return "You only need some work experience!";
      }
    }
  return "Not eligible";
  }
}

This code still has a nested ifs and can be improved further!

🔗

Practice Code Structure

Section 1.20 Code Refactoring

Activity 1.20.1.

Activity 1.20.2.