build plugin tree

scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginLoader.java

@@ -226,7 +226,7 @@ public class DefaultPluginLoader implements PluginLoader
           {
             injectionModules.add((Module) extensionClass.newInstance());
           }
-          catch (Exception ex)
+          catch (IllegalAccessException | InstantiationException ex)
           {
             logger.error("could not create instance of module", ex);
           }

scm-webapp/src/main/java/sonia/scm/plugin/PluginNode.java

@@ -0,0 +1,191 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.plugin;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.util.List;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public final class PluginNode
+{
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param plugin
+   */
+  public PluginNode(ExplodedSmp plugin)
+  {
+    this.plugin = plugin;
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param node
+   */
+  public void addChild(PluginNode node)
+  {
+    this.children.add(node);
+    node.addParent(this);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param node
+   */
+  private void addParent(PluginNode node)
+  {
+    this.parents.add(node);
+  }
+
+  //~--- get methods ----------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param id
+   *
+   * @return
+   */
+  public PluginNode getChild(final String id)
+  {
+    return Iterables.find(children, new Predicate<PluginNode>()
+    {
+
+      @Override
+      public boolean apply(PluginNode node)
+      {
+        return node.getId().equals(id);
+      }
+    });
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public List<PluginNode> getChildren()
+  {
+    return children;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public String getId()
+  {
+    return plugin.getPlugin().getInformation().getId(false);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public List<PluginNode> getParents()
+  {
+    return parents;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public ExplodedSmp getPlugin()
+  {
+    return plugin;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public PluginWrapper getWrapper()
+  {
+    return wrapper;
+  }
+
+  //~--- set methods ----------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param wrapper
+   */
+  public void setWrapper(PluginWrapper wrapper)
+  {
+    this.wrapper = wrapper;
+  }
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** Field description */
+  private final List<PluginNode> parents = Lists.newArrayList();
+
+  /** Field description */
+  private final List<PluginNode> children = Lists.newArrayList();
+
+  /** Field description */
+  private final ExplodedSmp plugin;
+
+  /** Field description */
+  private PluginWrapper wrapper;
+}

scm-webapp/src/main/java/sonia/scm/plugin/PluginProcessor.java

@@ -37,7 +37,6 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableList.Builder;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
-import com.google.common.collect.Ordering;
 import com.google.common.collect.Sets;
 import com.google.common.hash.Hashing;
 
@@ -147,7 +146,7 @@ public final class PluginProcessor
    *
    * @throws IOException
    */
-  private static DefaultPluginClassLoader createClassLoader(
+  private DefaultPluginClassLoader createClassLoader(
     ClassLoader parentClassLoader, Path directory)
     throws IOException
   {
@@ -256,17 +255,97 @@ public final class PluginProcessor
     }
 
     List<ExplodedSmp> smps = Lists.transform(dirs, new PathTransformer());
-    Iterable<ExplodedSmp> smpOrdered = Ordering.natural().sortedCopy(smps);
 
-    Set<PluginWrapper> pluginWrappers = createPluginWrappers(classLoader,
-                                          smpOrdered);
+    logger.trace("start building plugin tree");
+
+    List<PluginNode> rootNodes = new PluginTree(smps).getRootNodes();
+
+    logger.trace("create plugin wrappers and build classloaders");
+
+    Set<PluginWrapper> wrappers = createPluginWrappers(classLoader, rootNodes);
 
     if (logger.isDebugEnabled())
     {
-      logger.debug("collected {} plugins", pluginWrappers.size());
+      logger.debug("collected {} plugins", wrappers.size());
     }
 
-    return ImmutableSet.copyOf(pluginWrappers);
+    return ImmutableSet.copyOf(wrappers);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param plugins
+   * @param classLoader
+   * @param node
+   *
+   * @throws IOException
+   */
+  private void appendPluginWrapper(Set<PluginWrapper> plugins,
+    ClassLoader classLoader, PluginNode node)
+    throws IOException
+  {
+    ExplodedSmp smp = node.getPlugin();
+
+    List<ClassLoader> parents = Lists.newArrayList();
+
+    for (PluginNode parent : node.getParents())
+    {
+      PluginWrapper wrapper = parent.getWrapper();
+
+      if (wrapper != null)
+      {
+        parents.add(wrapper.getClassLoader());
+      }
+      else
+      {
+        //J-
+        throw new PluginLoadException(
+          String.format(
+            "parent %s of plugin %s is not ready", parent.getId(), node.getId()
+          )
+        );
+        //J+
+      }
+
+    }
+
+    PluginWrapper plugin =
+      createPluginWrapper(createParentPluginClassLoader(classLoader, parents),
+        smp.getPath());
+
+    if (plugin != null)
+    {
+      plugins.add(plugin);
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param plugins
+   * @param classLoader
+   * @param nodes
+   *
+   * @throws IOException
+   */
+  private void appendPluginWrappers(Set<PluginWrapper> plugins,
+    ClassLoader classLoader, List<PluginNode> nodes)
+    throws IOException
+  {
+    
+    // TODO fix plugin loading order
+    for (PluginNode node : nodes)
+    {
+      appendPluginWrapper(plugins, classLoader, node);
+    }
+
+    for (PluginNode node : nodes)
+    {
+      appendPluginWrappers(plugins, classLoader, node.getChildren());
+    }
   }
 
   /**
@@ -366,6 +445,37 @@ public final class PluginProcessor
     }
   }
 
+  /**
+   * Method description
+   *
+   *
+   * @param root
+   * @param parents
+   *
+   * @return
+   */
+  private ClassLoader createParentPluginClassLoader(ClassLoader root,
+    List<ClassLoader> parents)
+  {
+    ClassLoader result;
+    int size = parents.size();
+
+    if (size == 0)
+    {
+      result = root;
+    }
+    else if (size == 1)
+    {
+      result = parents.get(0);
+    }
+    else
+    {
+      result = new MultiParentClassLoader(parents);
+    }
+
+    return result;
+  }
+
   /**
    * Method description
    *
@@ -407,26 +517,19 @@ public final class PluginProcessor
    *
    * @param classLoader
    * @param smps
+   * @param rootNodes
    *
    * @return
    *
    * @throws IOException
    */
   private Set<PluginWrapper> createPluginWrappers(ClassLoader classLoader,
-    Iterable<ExplodedSmp> smps)
+    List<PluginNode> rootNodes)
     throws IOException
   {
     Set<PluginWrapper> plugins = Sets.newHashSet();
 
-    for (ExplodedSmp smp : smps)
-    {
-      PluginWrapper plugin = createPluginWrapper(classLoader, smp.getPath());
-
-      if (plugin != null)
-      {
-        plugins.add(plugin);
-      }
-    }
+    appendPluginWrappers(plugins, classLoader, rootNodes);
 
     return plugins;
   }

scm-webapp/src/main/java/sonia/scm/plugin/PluginTree.java

@@ -0,0 +1,210 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.plugin;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Ordering;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public final class PluginTree
+{
+
+  /**
+   * the logger for PluginTree
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(PluginTree.class);
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param smps
+   */
+  public PluginTree(ExplodedSmp... smps)
+  {
+    this(Arrays.asList(smps));
+  }
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param smps
+   */
+  public PluginTree(List<ExplodedSmp> smps)
+  {
+    Iterable<ExplodedSmp> smpOrdered = Ordering.natural().sortedCopy(smps);
+
+    for (ExplodedSmp smp : smpOrdered)
+    {
+      Plugin plugin = smp.getPlugin();
+      PluginCondition condition = plugin.getCondition();
+
+      if ((condition == null) || condition.isSupported())
+      {
+        Set<String> dependencies = plugin.getDependencies();
+
+        if ((dependencies == null) || dependencies.isEmpty())
+        {
+          rootNodes.add(new PluginNode(smp));
+        }
+        else
+        {
+          appendNode(rootNodes, dependencies, smp);
+        }
+      }
+      else
+      {
+        //J-
+        throw new PluginConditionFailedException(
+          condition, 
+          String.format(
+            "could not load plugin %s, the plugin condition does not match",
+            plugin.getInformation().getId()
+          )
+        );
+        //J+
+      }
+    }
+  }
+
+  //~--- get methods ----------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @return
+   */
+  public List<PluginNode> getRootNodes()
+  {
+    return rootNodes;
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param nodes
+   * @param dependencies
+   * @param smp
+   */
+  private void appendNode(List<PluginNode> nodes, Set<String> dependencies,
+    ExplodedSmp smp)
+  {
+    PluginNode child = new PluginNode(smp);
+
+    for (String dependency : dependencies)
+    {
+      if (!appendNode(nodes, child, dependency))
+      {
+        //J-
+        throw new PluginNotInstalledException(
+          String.format(
+            "dependency %s of %s is not installed", 
+            dependency,
+            child.getId()
+          )
+        );
+        //J+
+      }
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param nodes
+   * @param child
+   * @param dependency
+   *
+   * @return
+   */
+  private boolean appendNode(List<PluginNode> nodes, PluginNode child,
+    String dependency)
+  {
+    logger.debug("check for {} {}", dependency, child.getId());
+
+    boolean found = false;
+
+    for (PluginNode node : nodes)
+    {
+      if (node.getId().equals(dependency))
+      {
+        logger.debug("add plugin {} as child of {}", child.getId(),
+          node.getId());
+        node.addChild(child);
+        found = true;
+
+        break;
+      }
+      else
+      {
+        if (appendNode(node.getChildren(), child, dependency))
+        {
+          found = true;
+
+          break;
+        }
+
+      }
+    }
+
+    return found;
+  }
+
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** Field description */
+  private final List<PluginNode> rootNodes = Lists.newArrayList();
+}

scm-webapp/src/test/java/sonia/scm/plugin/PluginProcessorTest.java

@@ -0,0 +1,54 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+package sonia.scm.plugin;
+
+import java.io.IOException;
+import org.junit.Test;
+import static org.junit.Assert.*;
+import org.junit.Rule;
+import org.junit.rules.TemporaryFolder;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public class PluginProcessorTest
+{
+  
+  @Rule
+  public TemporaryFolder temp = new TemporaryFolder();
+
+  @Test
+  public void testBuildPluginTree() throws IOException
+  {
+    PluginProcessor processor = new PluginProcessor(temp.newFolder().toPath());
+  }
+  
+}

scm-webapp/src/test/java/sonia/scm/plugin/PluginTreeTest.java

@@ -0,0 +1,268 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.plugin;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.base.Function;
+import com.google.common.collect.Lists;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import static org.hamcrest.Matchers.*;
+
+import static org.junit.Assert.*;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.io.IOException;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public class PluginTreeTest
+{
+
+  /**
+   * Method description
+   *
+   *
+   * @throws IOException
+   */
+  @Test(expected = PluginConditionFailedException.class)
+  public void testPluginConditionFailed() throws IOException
+  {
+    PluginCondition condition = new PluginCondition("999",
+                                  new ArrayList<String>(), "hit");
+    Plugin plugin = new Plugin(createInfo("a", "b", "1"), null, condition,
+                      null);
+    ExplodedSmp smp = createSmp(plugin);
+
+    new PluginTree(smp).getRootNodes();
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @throws IOException
+   */
+  @Test(expected = PluginNotInstalledException.class)
+  public void testPluginNotInstalled() throws IOException
+  {
+    new PluginTree(createSmpWithDependency("b", "a")).getRootNodes();
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @throws IOException
+   */
+  @Test
+  public void testRootNotes() throws IOException
+  {
+    List<ExplodedSmp> smps = createSmps("a", "b", "c");
+    List<String> nodes = unwrapIds(new PluginTree(smps).getRootNodes());
+
+    assertThat(nodes, containsInAnyOrder("a:a", "b:b", "c:c"));
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @throws IOException
+   */
+  @Test
+  public void testSimpleDependencies() throws IOException
+  {
+    //J-
+    ExplodedSmp[] smps = new ExplodedSmp[] { 
+      createSmpWithDependency("a"),
+      createSmpWithDependency("b", "a"),
+      createSmpWithDependency("c", "a", "b") 
+    };
+    //J+
+
+    PluginTree tree = new PluginTree(smps);
+    List<PluginNode> rootNodes = tree.getRootNodes();
+
+    assertThat(unwrapIds(rootNodes), containsInAnyOrder("a:a"));
+
+    PluginNode a = rootNodes.get(0);
+
+    assertThat(unwrapIds(a.getChildren()), containsInAnyOrder("b:b", "c:c"));
+
+    PluginNode b = a.getChild("b:b");
+
+    assertThat(unwrapIds(b.getChildren()), containsInAnyOrder("c:c"));
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param groupId
+   * @param artifactId
+   * @param version
+   *
+   * @return
+   */
+  private PluginInformation createInfo(String groupId, String artifactId,
+    String version)
+  {
+    PluginInformation info = new PluginInformation();
+
+    info.setGroupId(groupId);
+    info.setArtifactId(artifactId);
+    info.setVersion(version);
+
+    return info;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param plugin
+   *
+   * @return
+   *
+   * @throws IOException
+   */
+  private ExplodedSmp createSmp(Plugin plugin) throws IOException
+  {
+    return new ExplodedSmp(tempFolder.newFile().toPath(), plugin);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param name
+   *
+   * @return
+   *
+   * @throws IOException
+   */
+  private ExplodedSmp createSmp(String name) throws IOException
+  {
+    return createSmp(new Plugin(createInfo(name, name, "1.0.0"), null, null,
+      null));
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param name
+   * @param dependencies
+   *
+   * @return
+   *
+   * @throws IOException
+   */
+  private ExplodedSmp createSmpWithDependency(String name,
+    String... dependencies)
+    throws IOException
+  {
+    Set<String> dependencySet = new HashSet<>();
+
+    for (String d : dependencies)
+    {
+      dependencySet.add(d.concat(":").concat(d));
+    }
+
+    Plugin plugin = new Plugin(createInfo(name, name, "1"), null, null,
+                      dependencySet);
+
+    return createSmp(plugin);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param names
+   *
+   * @return
+   *
+   * @throws IOException
+   */
+  private List<ExplodedSmp> createSmps(String... names) throws IOException
+  {
+    List<ExplodedSmp> smps = Lists.newArrayList();
+
+    for (String name : names)
+    {
+      smps.add(createSmp(name));
+    }
+
+    return smps;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param nodes
+   *
+   * @return
+   */
+  private List<String> unwrapIds(List<PluginNode> nodes)
+  {
+    return Lists.transform(nodes, new Function<PluginNode, String>()
+    {
+
+      @Override
+      public String apply(PluginNode input)
+      {
+        return input.getId();
+      }
+    });
+  }
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** Field description */
+  @Rule
+  public TemporaryFolder tempFolder = new TemporaryFolder();
+}