pmd: let failing rules fail the unit tests again

so that we can early detect any introduced exceptions (like NPE).

pmd/src/main/java/net/sourceforge/pmd/RuleContext.java

@@ -33,6 +33,7 @@ public class RuleContext {
     private String sourceCodeFilename;
     private LanguageVersion languageVersion;
     private final Map<String, Object> attributes;
+    private boolean ignoreExceptions = true;
 
     /**
      * Default constructor.
@@ -189,4 +190,28 @@ public class RuleContext {
     public Object removeAttribute(String name) {
 	return this.attributes.remove(name);
     }
+
+    /**
+     * Configure whether exceptions during applying a rule should be ignored or not.
+     * If set to <code>true</code> then such exceptions are logged as warnings and
+     * the processing is continued with the next rule - the failing rule is simply skipped.
+     * This is the default behavior.
+     * <br>
+     * If set to <code>false</code> then the processing will be aborted with the exception.
+     * This is especially useful during unit tests, in order to not oversee any exceptions.
+     * @param ignoreExceptions if <code>true</code> simply skip failing rules (default).
+     */
+    public void setIgnoreExceptions(boolean ignoreExceptions) {
+        this.ignoreExceptions = ignoreExceptions;
+    }
+
+    /**
+     * Gets the configuration whether to skip failing rules (<code>true</code>)
+     * or whether to throw a a RuntimeException and abort the processing for the first
+     * failing rule.
+     * @return <code>true</code> when failing rules are skipped, <code>false</code> otherwise.
+     */
+    public boolean isIgnoreExceptions() {
+        return ignoreExceptions;
+    }
 }

pmd/src/main/java/net/sourceforge/pmd/RuleSet.java

@@ -239,7 +239,11 @@ public class RuleSet {
             } catch (ThreadDeath td) {
                 throw td;
             } catch (Throwable t) {
-                LOG.log(Level.WARNING, "Exception applying rule " + rule.getName() + ", continuing with next rule", t);
+                if (ctx.isIgnoreExceptions()) {
+                    LOG.log(Level.WARNING, "Exception applying rule " + rule.getName() + ", continuing with next rule", t);
+                } else {
+                    throw new RuntimeException(t);
+                }
             }
 		}
 	}

pmd/src/test/java/net/sourceforge/pmd/testframework/RuleTst.java

@@ -124,6 +124,7 @@ public abstract class RuleTst {
         ctx.setReport(report);
         ctx.setSourceCodeFilename("n/a");
         ctx.setLanguageVersion(languageVersion);
+        ctx.setIgnoreExceptions(false);
         RuleSet rules = new RuleSet();
         rules.addRule(rule);
         p.getSourceCodeProcessor().processSourceCode(new StringReader(code), new RuleSets(rules), ctx);