Challenge - Resolving Rectangle

Quick Index

Objectives
Description
Provided Code
Unit (Model)
Project Directory Structure
Challenge Rules
Expected Unit Test Output
Bug Summary
Deliverable (Output)

Refresh on Java packaging
Refresh on how to code using class and especially method headers
Learn if unit tests (smoke tests) are effective
Learn how to find bugs using unit tests
Learn how to infer bug location (in code) from errors/exceptions

For this challenge the coder will apply smoke tests to a Rectangle unit (class) in an effort to look for showstopper bugs.

The coder is provided with:

A unit test class (RectangleTest) -- code must not be changed
A unit class (Rectangle) -- code has numerous bugs -- code will require changes/fixes

The challenge is to use the unit test to identify bugs, and then resolve the bugs. A "bug summary" must be prepared.

Good luck coder!

Provided Code

Download the provided code to a working area of your computer
Open in your favorite IDE or source code editor
If using an IDE, verify the project imported correctly (see "Project Directory Structure" below) -- adjust as needed

Unit (Model)

For this example, we will be testing a unit named Rectangle.

The Rectangle class summary and key method summaries are shown below. We will use these summaries when coding the tests.

Rectangle Structure

class name: Rectangle
access: public
package: model.shapes

Rectangle Method Headers

The smoke tests exercise the following methods:

/** Returns new Rectangle object with passed lat and long values */
public static Rectangle fromUpperLeftWidthHeight(int left, int top, int w, int h)

/** Returns new Rectangle object with upper left (0, 0) and dimensions = 0 */
public static Rectangle newInstance()

/** Returns nice display string for this Rectangle */
public String toString()

Point Method Headers

Pertinent method headers for the Point type are shown below (just in case you need them for bug fixes).

/** Returns new Point with x and y set from params */
public static Point fromXY(int aX, int aY)

/** Returns new Point at origin (0, 0) */
public static Point newOrigin()

/** Returns "nice string" of this Point */
public String toString()

Project Directory Structure

Here is the project directory structure with primary players noted.

Note that classpath (Java) is also called build path (Eclipse) or source folder (IntelliJ).

+---src←classpath
⁠
|   +---model
|   |   +---shapes
|   |       \---Rectangle.java←Unit
|   |       \---FullName.java
|   +---test
|   |    +---cases
|   |        +---shapes
|   |               \---RectangleTest.java←Unit
Test
|   |
    \---rectangle-bug-summary.txt←Bug summary
starter file

Challenge Rules

Follow the steps presented in the chapter (see example)
Complete a bug summary (see "Bug Summary" section below)
Identify and fix bugs until the code runs smoothly and generates the expected output (see below)
Let the unit tests identify bugs for you (do not identify them manually by browsing code)

Note: The referenced "example" is the example from this chapter

Expected Unit Test Output

Once all the showstopper bugs have been identified and fixed this is the expected output when running the unit test.


-- test_newInstance --
(left, top, right, bottom) = (0, 0, 0, 0)

-- test_fromUpperLeftWidthHeight --
(left, top, right, bottom) = (100, 50, 110, 55)

Bug Summary

Complete a "bug summary"
It must follow the same format as the example bug summary in this chapter
It must be saved in the provided starter file "rectangle-bug-summary.txt"
It must be a plain text file
The bugs described in the summary should be in the order they surface in the unit test code (like the example shows)

Note: The referenced "example" is the example from this chapter

Deliverable (Output)

The deliverable (product) for this challenge is the file "rectangle-bug-summary.txt".

Unit Testing (Chapter 202 - Unit Testing - Smoke Tests - Bug Finding)

Chapter 202 - Unit Testing - Smoke Tests - Bug Finding Challenge - Resolving Rectangle Bugs

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