Question

You have been asked to test a method called 'catWhiteSpace' in a 'Paragraph' object that, within the paragraph, replaces sequences of blank characters with a single blank character. Identify testing partitions for this example and derive a set of tests for the 'catWhiteSpace' method.

Short answer

Define input partitions, outline edge and regular test cases, determine expected results, and design a test plan.

Step-by-step solution

Identify Input Domains

First, we need to identify different types of input data that could be given to the 'catWhiteSpace' method. Potential input partitions include: 1) Strings with no whitespace. 2) Strings with single spaces only. 3) Strings with multiple consecutive spaces. 4) Strings with mixed whitespace characters (spaces, tabs, etc.). 5) Empty strings or strings with only whitespace. 6) Very long strings with numerous whitespaces.

Define Edge Cases and Regular Cases

Next, define edge cases and regular test cases based on the input domains identified: - Edge Case 1: An empty string. - Edge Case 2: A string that is entirely made up of whitespace characters. - Regular Case 1: A string with no whitespace characters (e.g., 'HelloWorld'). - Regular Case 2: A string with multiple consecutive spaces (e.g., 'Hello World'). - Regular Case 3: A string with mixed spaces and tabs (e.g., 'Hello World'). - Regular Case 4: A very long string with many sequences of whitespaces.

Determine Expected Results

For each test case defined, determine the expected output: - Test Case for Edge Case 1: Input -> ''; Expected Output -> ''. - Test Case for Edge Case 2: Input -> ' '; Expected Output -> ' ' (a single space). - Test Case for Regular Case 1: Input -> 'HelloWorld'; Expected Output -> 'HelloWorld'. - Test Case for Regular Case 2: Input -> 'Hello World'; Expected Output -> 'Hello World'. - Test Case for Regular Case 3: Input -> 'Hello World'; Expected Output -> 'Hello World'. - Test Case for Regular Case 4: Input -> (very long string with sequences of whitespaces); Expected Output -> (same string with each sequence of whitespaces replaced by a single space).

Design Test Plan

Compile the test cases into a plan to systematically verify the 'catWhiteSpace' method's functionality. Test Plan: - Run Edge Case 1 and verify output. - Run Edge Case 2 and verify output. - Execute Regular Case 1, 2, 3, and 4, checking each result against the expected output. Each test should validate that the output matches the expected results as determined in Step 3.

Key concepts

Test Cases

In software testing, a test case is a specific scenario used to check whether a software function works as expected. For the 'catWhiteSpace' method, test cases include different string inputs that represent various scenarios. Test cases help us verify the function's behavior under different conditions, such as strings with no whitespace, multiple spaces, mixed whitespace, and more. Each test case comes with specific inputs and their corresponding expected outputs. By running these test cases, we can observe if the 'catWhiteSpace' method correctly compresses multiple whitespace characters into a single space.

Input Partitions

Breaking down input data into input partitions is a skillful approach in software testing. Input partitions are categories of inputs that are expected to exhibit similar behavior when processed by the software. For the 'catWhiteSpace' method, these partitions can help cover a wide range of scenarios without needing to test every possible input. Some partitions for this method might include:

• Strings with no whitespace
• Strings with single spaces
• Strings with sequences of whitespace
• Mixed whitespace characters (spaces, tabs, etc.)
• Empty strings or those with only whitespace
• Very long strings

These partitions allow testers to create focused and efficient test cases by selecting representative samples from each partition.

Edge Cases

Edge cases are special input scenarios that test the boundaries of a function's capabilities. They are crucial because they often uncover issues that regular input cases might miss. For the 'catWhiteSpace' method, edge cases could include an empty string or a string composed entirely of spaces. These cases help ensure that the method handles unexpected or extreme inputs gracefully and without errors. Testing edge cases is important because it confirms that the method can manage inputs at the limits of what might be considered usual, which helps in preventing potential errors in real-world applications.

Test Plan

A test plan is an organized framework that outlines how test cases will be conducted. It ensures a systematic approach to testing and helps in tracking the testing process. For the 'catWhiteSpace' method, the test plan should include running each test case according to the input partitions and edge cases defined earlier. This plan should ensure that:

• Each test case is executed and the output is verified against expected results.
• Any discrepancies between actual and expected outcomes are recorded for review.
• All edge cases and regular scenarios are covered thoroughly.

By following the test plan, testers can comprehensively evaluate the 'catWhiteSpace' method's performance and identify areas for improvement before deployment.