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[MO-java-dev] CVS: mockobjects-java/doc/html faq.html,1.1,1.2
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From: Jeff M. <cus...@us...> - 2002-09-02 10:24:40
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Update of /cvsroot/mockobjects/mockobjects-java/doc/html
In directory usw-pr-cvs1:/tmp/cvs-serv1324/html
Modified Files:
faq.html
Log Message:
Added additions from ted and split into sections
Index: faq.html
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RCS file: /cvsroot/mockobjects/mockobjects-java/doc/html/faq.html,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- faq.html 29 Aug 2002 12:57:50 -0000 1.1
+++ faq.html 2 Sep 2002 10:24:37 -0000 1.2
@@ -1,66 +1,128 @@
-<ul>
- <li>
+<h1>MockObject FAQ</h1>
+<h2>General Questions About Mocks</h2>
<h3>What's a mock object?</h3>
- <p>
- It's a thing!
+
+ <p>A mock object is a "double agent" used to test the behavior
+of other objects. First, a mock object acts as a faux implementation
+of an interface or class that simulates the external behavior of a true implementation.
+Second, a mock object observes how other objects interact with its
+methods and compares actual behavior with preset expectations. When a discrepancy
+occurs, a mock object can interrupt the test and report the anomaly. If the
+discrepancy cannot be noted during the test, a verification method called
+by the tester ensures that all expectations have been met or failures reported.<br>
</p>
- </li>
- <li>
+
<h3>What's an expectation?</h3>
- <p>
- It's another thing!
- </p>
- </li>
- <li>
+
+ <p>When any component is used in a program, we anticipate a set of preconditions
+and postconditions. For example, we might anticipate that a database connection
+will be used once and then closed. We might also anticipate that a JDBC ResultSet
+will be passed a certain set of parameters for use with a given SQL command.
+A mock object can be told to expect conditions such as these, so that it
+can report back when our expectations are not met. The MockObjects API has
+refactored this mechanism into a framework of Expectation classes. </p>
+
<h3>Why should I bother?</h3>
- <p>
- </p>
- </li>
- <li>
+<p>Today, most developers recognize the value of unit testing. But many developers
+also find that creating and maintaining non-trivial unit tests becomes difficult
+as products mature. Writing significant unit tests can tempt developers into
+making objects "test-aware". This can complicate production code and begins
+to defeat the purpose of unit testing. Mock objects simplify the creation
+and maintenance of non-trivial unit tests by allowing us to test one object
+at a time. Mock objects make it possible to test an object without its knowledge.</p>
+<p>
+Mock objects allow you to unit test your application independently of the
+production infrastructure. Developers do not need access to a real database
+to run the unit tests. The same is true of any external resource, including
+hardware devices.</p>
+<p>
+Mock objects can also simulate states that may be difficult or time-consuming
+to realize in a runtime environment. A mock object can throw any exception
+or produce any error condition on demand. For example, using a real database,
+to see how an object will react to an offline database you would have to
+actually down the database. Using a mock JDBC connection, you can simulate
+a dead database in one test and a live database in the next, all in a fraction
+of a second.</p>
+ <p>
+As products mature, and test suites grow larger, tracing the cause of a failed
+test can become difficult. A mock implementation can test assertions each
+time it interacts with production (or "domain") code. The test is then more
+likely to fail at the right time and generate a useful message. </p>
+ <p>
+We can also build base assertions about how domain objects are suppose to
+work into our mock objects. These assertions can be applied automatically
+whenever the mock object is used. This ensures that our base assertions remain
+true as the application matures. </p>
+ <p>
+We use mock objects because they allow us to quickly create inexpensive,
+effective tests that are easy to maintain. </p>
+
+ <h3>Do I have to change the way I write my programs?</h3>
+<p>Usually not. In fact , mock objects should make it easier to test your programs
+without making changes to your production objects. Generally, the better
+designed your application, the easier it should be to test with mock objects.
+If an application does not test well, there are usually ways to improve its
+design and provide better testability. In practice, many developers
+find that approaching new development with a test-first perspective helps
+them write better programs more quickly. Writing tests for features helps
+defines the objects we need to provide those features. Test-driven design
+helps us discover the interfaces our objects actually need</p>
+
+ <h3>What are some of the patterns used to create tests with mock objects?</h3>
+ <h3>Who discovered mock objects?</h3>
+ <h3>What is the difference between stub objects and mock objects?</h3>
+
+
+<h2>About the Mock Object Implementation</h2>
+
+
<h3>Why do I have to call setup???? to instead of set??? to add something to
a map?</h3>
<p>
</p>
- </li>
- <li>
+
+
<h3>Who do I contribute changes back to the mock objects project?</h3>
<p>
</p>
- </li>
- <li>
+
+
<h3>What does it mean when I get a NotImplementedException?</h3>
<p>
</p>
- </li>
- <li>
+
+
<h3>How do I write a mock?</h3>
<p>
</p>
- </li>
- <li>
+
+
<h3>Why don't mocks verify their expectations?</h3>
<p>
</p>
- </li>
- <li>
+
+
<h3>What are the alt.* packages for?</h3>
<p>
</p>
- </li>
- <li>
+
+
<h3>What do I do if I can't find a mock for a class?</h3>
<p>
</p>
- </li>
- <li>
+
+
<h3>Are there any tools to help create mocks?</h3>
<p>
</p>
- </li>
- <li>
- <h3>Why are the internals of mock private when there just test classes?</h3>
- <p>
- </p>
- </li>
-</ul>
+
+
+ <h3>Why are the internals of mock private when there just test class?</h3>
+ <h3>What is the best practice for integrating mocks into a project?</h3>
+
+<h2>Other Questions</h2>
+
+ <h3>What are the differences between the EasyMock and MockMaker approaches?</h3>
+
+
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