[MO-java-dev] CVS: no-stone-unturned/doc/xdocs a_longer_example.xml,1.3,1.4

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Update of /cvsroot/mockobjects/no-stone-unturned/doc/xdocs
In directory usw-pr-cvs1:/tmp/cvs-serv3673/doc/xdocs

Modified Files:
	a_longer_example.xml 
Log Message:
first working servlet test, no answers found

Index: a_longer_example.xml
===================================================================
RCS file: /cvsroot/mockobjects/no-stone-unturned/doc/xdocs/a_longer_example.xml,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -r1.3 -r1.4

--- a_longer_example.xml	27 Aug 2002 19:17:33 -0000	1.3
+++ a_longer_example.xml	2 Sep 2002 22:40:11 -0000	1.4
@@ -114,7 +114,7 @@
       <programlisting>
     HttpServletRequest mockRequest = new NullHttpServletRequest() {
       public String getMethod() {
-        return "PUT";
+        return "GET";
       }
       public String getProtocol() {
         return "HTTP/1.1";
@@ -157,11 +157,178 @@
           As you've seen in the first example, now we only have to override the methods that we use in our test.
         </para>
       </sidebar>
-    </section>
+    </section> <!-- We accept a name and find no result -->
+
+    <section>
+      <title>We write our first implementation of the servlet</title>
+      <para>
+        So we've finally got our servlet doing nothing, so let's make it do what we need to get through the
+        first task.  The first step is to extend our test with the output we expect to see:
+      </para>
+      <programlisting>
+public void testNoEntries() throws ServletException, IOException {
+  <emphasis>final StringWriter page = new StringWriter();</emphasis>
+
+  HttpServletRequest mockRequest = new NullHttpServletRequest() {
+    public String getMethod() {
+      return "GET";
+    }
+    public String getProtocol() {
+      return "HTTP/1.1";
+    }
+  };
+  <emphasis>HttpServletResponse mockResponse = new NullHttpServletResponse() {
+    public PrintWriter getWriter() throws IOException {
+      return new PrintWriter(page);
+    }
+  };</emphasis>
+
+  AddressBookServlet servlet = new AddressBookServlet();
+  servlet.service(mockRequest, mockResponse);
+
+  <emphasis>assertEquals("Should be empty response", "No address found", page.toString().trim());</emphasis>
+}</programlisting>
+      <para>
+        The <classname>HttpServletResponse</classname> interface provides a <classname>PrintWriter</classname> that
+        the servlet can use to write out the page that it wants to send back to the browser. We've implemented this
+        by wrapping a <classname>StringWriter</classname> that's declared as a variable in the test. We can check
+        whether our servlet has written out something like the right page contents with a simple comparison at the end
+        of the test. We've also trimmed our output string to avoid disagreements over new lines.
+        Let's run the test.
+      </para>
+
+      &redbar;
+      <screen>
+There was 1 failure:
+1) testNoEntries(nostone.addressbook.AddressBookServletTest)
+AssertionFailedError: Response page expected:&lt;No address found&gt; but was:&lt;&gt;
+	at nostone.addressbook.AddressBookServletTest.testNoEntries(AddressBookServletTest.java:41)
+FAILURES!!!
+Tests run: 1,  Failures: 1,  Errors: 0</screen>
+
+      <para>
+        Good, our test has failed. We haven't yet implemented the relevant method in the servlet, so let's
+        write just enough code to get our green bar back.
+      </para>
+
+      <programlisting>
+public class AddressBookServlet extends HttpServlet {
+
+  <emphasis>protected void doGet(HttpServletRequest req, HttpServletResponse resp)
+       throws ServletException, IOException
+   {
+     resp.getWriter().println( "No address found" );
+   }</emphasis>
+}</programlisting>
+
+      &greenbar;
+      <para>
+        Now the test passes because the returned page matches the text we asked for &mdash; we said
+        <emphasis>just</emphasis> enough code to pass the test, and we meant it. There's one more thing missing
+        before we can sign off this task. The servlet response specification says that a servlet must set
+        the content type of the response before getting hold of a writer, and we have no test (and therefore no
+        implementation) for that. If we hold onto the content type in the mock response object, we can check that
+        it's been set before we get the writer.
+      </para>
+
+      <programlisting>
+  HttpServletResponse mockResponse = new NullHttpServletResponse() {
+    <emphasis>private String contentType;
+    public void setContentType(String aContentType) {
+      contentType = aContentType;
+    }</emphasis>
+
+    public PrintWriter getWriter() throws IOException {
+      <emphasis>assertNotNull("Should have content type", contentType);</emphasis>
+      return new PrintWriter(page);
+    }
+  };</programlisting>
+
+      <para>
+        Of course this fails
+      </para>
+
+      &redbar;
+      <screen>
+There was 1 failure:
+1) testNoEntries(nostone.addressbook.AddressBookServletTest)
+AssertionFailedError: Should have content type
+	at nostone.addressbook.AddressBookServletTest$2.getWriter(AddressBookServletTest.java:33)
+	<emphasis>at nostone.addressbook.AddressBookServlet.doGet(AddressBookServlet.java:16)</emphasis>
+	at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
+	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
+	at nostone.addressbook.AddressBookServletTest.testNoEntries(AddressBookServletTest.java:39)
+FAILURES!!!</screen>
+
+      <para>
+        The interesting thing about this failure report is that it's our first example that fails
+        <emphasis>within</emphasis> the production code, not the test case. The stack trace shows
+        that we detected the failure in the middle of <methodname>doGet()</methodname> when the
+        servlet is getting hold of the writer. Let's fix the problem by setting the content type
+        as we're supposed to.
+      </para>
+
+      <programlisting>
+protected void doGet(HttpServletRequest request, HttpServletResponse response)
+    throws ServletException, IOException
+{
+  <emphasis>response.setContentType("text/plan");</emphasis>
+  response.getWriter().println( "No address found" );
+}</programlisting>
+
+      &greenbar;
+
+      <para>
+        Done! Well, maybe not. One of us just noticed that we've set the content type to <quote>text/plan</quote>,
+        which is not what we meant. We want to test the value that we set for the content type as well. We could
+        just call <methodname>assertEquals("text/plain",...)</methodname> where now we call
+        <methodname>assertNotNull()</methodname>, but that wouldn't show us the failure until after it had
+        happened. Instead, we'll add an assertion to <methodname>setContentType()</methodname>.
+      </para>
+
+      <programlisting>
+  public void setContentType(String aContentType) {
+    <emphasis>assertEquals("Content type", "text/plain", aContentType);</emphasis>
+    contentType = aContentType;
+  }</programlisting>
+
+      &redbar;
+      <screen>
+There was 1 failure:
+1) testNoEntries(nostone.addressbook.AddressBookServletTest)
+<emphasis>AssertionFailedError: Content type expected:&lt;text/plain&gt; but was:&lt;text/plan&gt;</emphasis>
+	at nostone.addressbook.AddressBookServletTest$2.setContentType(AddressBookServletTest.java:28)
+	<emphasis>at nostone.addressbook.AddressBookServlet.doGet(AddressBookServlet.java:16)</emphasis>
+	at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
+	at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
+	at nostone.addressbook.AddressBookServletTest.testNoEntries(AddressBookServletTest.java:39)
+FAILURES!!!</screen>
+
+      <para>
+        Once again, our stacktrace shows us exactly where the failure happened and we can go straight in
+        and fix it.
+      </para>
+
+      <programlisting>
+protected void doGet(HttpServletRequest request, HttpServletResponse response)
+    throws ServletException, IOException
+{
+  response.setContentType(<emphasis>"text/plain"</emphasis>);
+  response.getWriter().println( "No address found" );
+}</programlisting>
+
+      &greenbar;
+
+      <para>
+        Now we're ready for our first acceptance test.
+      </para>
+    </section> <!-- We write our first implementation of the servlet -->
+
+    <!-- TODO -->
 
     <section>
       <title>accept a name and return a result from a hard-coded collection.</title>
-    </section>
+    </section> <!--  accept a name and return a result from a hard-coded collection -->
 
     <section>
       <title>
@@ -169,7 +336,7 @@
         Values are held in memory.
       </title>
     </section>
-  </chapter>
+  </chapter> <!-- Search for an entry in the book -->
 
   <chapter>
     <title>List all the entries in the book</title>



