Create Unit-Tests checking that nested archives are traversed

This required an extension of the UnitTesting support provided by SpotBugsRule to allow modifying the engine options
from within a test case.

spotbugs-tests/src/test/java/edu/umd/cs/findbugs/classfile/impl/ClassPathBuilderTest.java

@@ -0,0 +1,36 @@
+package edu.umd.cs.findbugs.classfile.impl;
+
+import edu.umd.cs.findbugs.AppVersion;
+import edu.umd.cs.findbugs.BugCollection;
+import edu.umd.cs.findbugs.test.SpotBugsRule;
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.nio.file.Paths;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+
+public class ClassPathBuilderTest {
+
+    @Rule
+    public SpotBugsRule analyzer = new SpotBugsRule();
+
+    @Test
+    public void nestedTraversalDisabled() {
+        BugCollection results = analyzer.performAnalysis((engine) -> {
+            engine.setScanNestedArchives(false);
+            engine.setNoClassOk(true);
+        }, Paths.get("../spotbugsTestCases/archives/nestedArchive.jar"));
+        AppVersion appInformation = results.getCurrentAppVersion();
+        assertThat(appInformation.getNumClasses(), equalTo(0));
+    }
+
+    @Test
+    public void nestedTraversalEnabled() {
+        BugCollection results = analyzer.performAnalysis((engine) -> engine.setScanNestedArchives(true),
+                Paths.get("../spotbugsTestCases/archives/nestedArchive.jar"));
+        AppVersion appInformation = results.getCurrentAppVersion();
+        assertThat(appInformation.getNumClasses(), equalTo(5));
+    }
+}

test-harness-core/src/main/java/edu/umd/cs/findbugs/test/AnalysisRunner.java

@@ -18,6 +18,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import java.util.function.Consumer;
 import java.util.jar.JarOutputStream;
 import java.util.zip.ZipEntry;
 
@@ -40,7 +41,7 @@
 /**
  * <p>
  * This class runs analysis with SpotBugs. The target class files and
- * auxClasspathEntries should be specified before you invoke {@link #run(Path...)}
+ * auxClasspathEntries should be specified before you invoke {@link #run(Consumer, Path...)}
  * method.
  * </p>
  *
@@ -83,7 +84,7 @@ public AnalysisRunner addAuxClasspathEntry(Path path) {
     }
 
     @Nonnull
-    public BugCollectionBugReporter run(Path... files) {
+    public BugCollectionBugReporter run(Consumer<IFindBugsEngine> engineCustomization, Path... files) {
         DetectorFactoryCollection.resetInstance(new DetectorFactoryCollection());
 
         try (FindBugs2 engine = new FindBugs2(); Project project = createProject(files)) {
@@ -102,6 +103,7 @@ public BugCollectionBugReporter run(Path... files) {
             preferences.enableAllDetectors(true);
             engine.setUserPreferences(preferences);
 
+            engineCustomization.accept(engine);
             try {
                 engine.execute();
             } catch (final IOException | InterruptedException e) {

test-harness/src/main/java/edu/umd/cs/findbugs/test/SpotBugsRule.java

@@ -1,10 +1,12 @@
 package edu.umd.cs.findbugs.test;
 
 import java.nio.file.Path;
+import java.util.function.Consumer;
 
 import javax.annotation.Nonnull;
 import javax.annotation.ParametersAreNonnullByDefault;
 
+import edu.umd.cs.findbugs.IFindBugsEngine;
 import org.junit.rules.ExternalResource;
 
 import edu.umd.cs.findbugs.BugCollection;
@@ -76,16 +78,32 @@ public SpotBugsRule addAuxClasspathEntry(Path path) {
      * <p>
      * Run SpotBugs under given condition, and return its result.
      * </p>
+     * @param engineCustomization
+     *      A customization of the engine to apply before running engine#execute
      * @param paths
      *     Paths of target class files
      * @return a {@link BugCollection} which contains all detected bugs.
      */
     // TODO let users specify SlashedClassName, then find its file path automatically
     @Nonnull
-    public BugCollection performAnalysis(Path... paths) {
+    public BugCollection performAnalysis(Consumer<IFindBugsEngine> engineCustomization, Path... paths) {
         if (runner == null) {
             throw new IllegalStateException("Please call this performAnalysis() method in test method");
         }
-        return runner.run(paths).getBugCollection();
+        return runner.run(engineCustomization, paths).getBugCollection();
+    }
+
+    /**
+     * <p>
+     * Run SpotBugs under given condition, and return its result.
+     * </p>
+     * @param paths
+     *     Paths of target class files
+     * @return a {@link BugCollection} which contains all detected bugs.
+     */
+    // TODO let users specify SlashedClassName, then find its file path automatically
+    @Nonnull
+    public BugCollection performAnalysis(Path... paths) {
+        return performAnalysis(e -> {}, paths);
     }
 }