refactor: allow TestReport to generate a formatted report

The report used for tests (`TestReport`) can now generate a formatted report.

- a new `setReportingFormat(String)` method is used to set the generated report format (can be "JSON", "XML", "XMP", or defaulting to a silent report)
- the `initialize()` method (Report API) is used to instantiate a delegate formatting report
- the `generate()` method (Report API) is used to finalize the formatted report delegate
- a new  `getOutput()` method is used to retrieve a String containing the formatted report

This formatting functionality is exposed as a cucumber step implemented in `TestConfiguration` and called with (in this example, for a JSON report):

```
   Given the reporting format is set to JSON
```

src/test/java/org/w3c/epubcheck/test/ExecutionSteps.java

@@ -43,14 +43,24 @@ public void check(String path)
     Locale oldDefaultLocale = Locale.getDefault();
     try
     {
+      // Complete configuration and get the test file 
       Locale.setDefault(configuration.getDefaultLocale());
-      File testFile = getEPUBFile(configuration.getBasepath() + path);
       if (configuration.getMode() == null)
       {
         configuration.setMode(CheckerMode.fromExtension(path));
       }
+      File testFile = getEPUBFile(configuration.getBasepath() + path);
+
+      // Initialize the report
+      configuration.getReport().setEpubFileName(testFile.getAbsolutePath());
+      configuration.getReport().initialize();
+
+      // Create the checker and run checks
       Checker checker = getChecker(testFile);
       checker.check();
+
+      // Finalize the report
+      configuration.getReport().generate();
     } finally
     {
       Locale.setDefault(oldDefaultLocale);

src/test/java/org/w3c/epubcheck/test/TestConfiguration.java

@@ -144,6 +144,12 @@ public void setProfile(EPUBProfile profile)
   {
     this.profile = profile;
   }
+
+  @And("(the )reporting format (is )set to {}")
+  public void setReportingFormat(String format)
+  {
+    report.setReportingFormat(format);
+  }
 
   @And("(the )reporting level (is )set to {severity}")
   public void setReportingLevel(Severity severity)

src/test/java/org/w3c/epubcheck/test/TestReport.java

@@ -1,5 +1,7 @@
 package org.w3c.epubcheck.test;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.EnumSet;
 import java.util.LinkedList;
 import java.util.List;
@@ -8,10 +10,15 @@
 
 import com.adobe.epubcheck.api.EPUBLocation;
 import com.adobe.epubcheck.api.MasterReport;
+import com.adobe.epubcheck.api.QuietReport;
+import com.adobe.epubcheck.api.Report;
 import com.adobe.epubcheck.messages.Message;
 import com.adobe.epubcheck.messages.MessageId;
 import com.adobe.epubcheck.messages.Severity;
+import com.adobe.epubcheck.reporting.CheckingReport;
 import com.adobe.epubcheck.util.FeatureEnum;
+import com.adobe.epubcheck.util.XmlReportImpl;
+import com.adobe.epubcheck.util.XmpReportImpl;
 import com.google.common.base.Function;
 import com.google.common.base.Functions;
 import com.google.common.base.Predicate;
@@ -59,8 +66,16 @@ public boolean apply(MessageInfo message)
         }
       });
 
+  /* Whether to output messages on System.out */
   private boolean verbose = false;
+  /* Stores the messages to be queried by assertions */
   private List<MessageInfo> messages = new LinkedList<MessageInfo>();
+  /* The output format (can be JSON/XML/XMP/text */
+  private String format = "default";
+  /* A delegate report, used mostly for output formatting */
+  private Report delegate = null;
+  /* a writer storing the report output */
+  private final StringWriter output = new StringWriter();
 
   public TestReport()
   {
@@ -80,6 +95,11 @@ public void message(Message message, EPUBLocation location, Object... args)
         fixMessage(message.getMessage(args)));
     if (verbose) System.out.println(messageInfo);
     messages.add(messageInfo);
+    // delegate to the formatting report
+    if (delegate != null)
+    {
+      delegate.message(message, location, args);
+    }
   }
 
   @Override
@@ -89,17 +109,45 @@ public void info(String resource, FeatureEnum feature, String value)
         fixMessage("[" + feature + "] " + value));
     if (verbose) System.out.println(messageInfo);
     messages.add(messageInfo);
+    // delegate to the formatting report
+    if (delegate != null)
+    {
+      delegate.info(resource, feature, value);
+    }
   }
 
   @Override
   public int generate()
   {
-    return 0;
+    int result = 0;
+    if (delegate != null)
+    {
+      result = delegate.generate();
+      if (verbose) System.out.println(output);
+    }
+    return result;
   }
 
   @Override
   public void initialize()
   {
+    assert format != null;
+    switch (format)
+    {
+    case "JSON":
+      delegate = new CheckingReport(new PrintWriter(output), getEpubFileName());
+      break;
+    case "XML":
+      delegate = new XmlReportImpl(new PrintWriter(output), getEpubFileName(), "test");
+      break;
+    case "XMP":
+      delegate = new XmpReportImpl(new PrintWriter(output), getEpubFileName(), "test");
+      break;
+    default:
+      delegate = QuietReport.INSTANCE;
+      break;
+    }
+    delegate.initialize();
   }
 
   public Iterable<MessageInfo> getAll(Severity severity)
@@ -144,11 +192,17 @@ public synchronized List<MessageInfo> consumeAll(Severity severity)
     messages = partition.get(false);
     return partition.get(true);
   }
-
-  public List<MessageInfo> getAllMessages() {
+
+  public List<MessageInfo> getAllMessages()
+  {
     return ImmutableList.copyOf(messages);
   }
 
+  public String getOutput()
+  {
+    return output.toString();
+  }
+
   private String fixMessage(String message)
   {
     if (message == null)
@@ -158,4 +212,12 @@ private String fixMessage(String message)
     return message.replaceAll("[\\s]+", " ");
   }
 
+  public void setReportingFormat(String format)
+  {
+    if (format != null)
+    {
+      this.format = format;
+    }
+  }
+
 }