SONAR-2505 support measure variations

13 files changed, 207 insertions, 47 deletions

diff --git a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/CorePlugin.java b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/CorePlugin.java
index c14be8d3310..f3b72b9e0c1 100644
--- a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/CorePlugin.java
+++ b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/CorePlugin.java
@@ -217,6 +217,7 @@ public class CorePlugin extends SonarPlugin {
     extensions.add(ReferenceAnalysis.class);
 
     // time machine
+    extensions.add(TimeMachineConfiguration.class);
     extensions.add(TendencyDecorator.class);
     extensions.add(VariationDecorator.class);
     extensions.add(ViolationTrackingDecorator.class);
diff --git a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewCoverageFileAnalyzer.java b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewCoverageFileAnalyzer.java
index d44ffd056e1..666d89082b5 100644
--- a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewCoverageFileAnalyzer.java
+++ b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewCoverageFileAnalyzer.java
@@ -32,7 +32,6 @@ import org.sonar.api.resources.Resource;
 import org.sonar.api.resources.Scopes;
 import org.sonar.api.utils.KeyValueFormat;
 import org.sonar.batch.components.PastSnapshot;
-import org.sonar.batch.components.TimeMachineConfiguration;
 import org.sonar.core.NotDryRun;
 
 import java.util.Arrays;
diff --git a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewViolationsDecorator.java b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewViolationsDecorator.java
index 86a150e28cd..4e00eb4c99f 100644
--- a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewViolationsDecorator.java
+++ b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/NewViolationsDecorator.java
@@ -31,7 +31,6 @@ import org.sonar.api.rules.Rule;
 import org.sonar.api.rules.RulePriority;
 import org.sonar.api.rules.Violation;
 import org.sonar.batch.components.PastSnapshot;
-import org.sonar.batch.components.TimeMachineConfiguration;
 import org.sonar.core.NotDryRun;
 
 import java.util.*;
diff --git a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TendencyDecorator.java b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TendencyDecorator.java
index ade65afb788..5a52622f9ec 100644
--- a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TendencyDecorator.java
+++ b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TendencyDecorator.java
@@ -31,7 +31,6 @@ import org.sonar.api.measures.MetricFinder;
 import org.sonar.api.resources.Project;
 import org.sonar.api.resources.Resource;
 import org.sonar.api.resources.Scopes;
-import org.sonar.batch.components.TimeMachineConfiguration;
 import org.sonar.core.NotDryRun;
 
 import java.util.List;
diff --git a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TimeMachineConfiguration.java b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TimeMachineConfiguration.java
new file mode 100644
index 00000000000..0ef49a93ea6
--- /dev/null
+++ b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TimeMachineConfiguration.java
@@ -0,0 +1,112 @@
+/*
+ * Sonar, open source software quality management tool.
+ * Copyright (C) 2008-2011 SonarSource
+ * mailto:contact AT sonarsource DOT com
+ *
+ * Sonar is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * Sonar is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Sonar; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
+ */
+package org.sonar.plugins.core.timemachine;
+
+import com.google.common.collect.Lists;
+import org.apache.commons.configuration.Configuration;
+import org.apache.commons.lang.StringUtils;
+import org.slf4j.LoggerFactory;
+import org.sonar.api.BatchExtension;
+import org.sonar.api.CoreProperties;
+import org.sonar.api.database.DatabaseSession;
+import org.sonar.api.database.model.Snapshot;
+import org.sonar.api.resources.Project;
+import org.sonar.api.resources.Qualifiers;
+import org.sonar.api.utils.Logs;
+import org.sonar.batch.components.PastSnapshot;
+import org.sonar.batch.components.PastSnapshotFinder;
+
+import javax.persistence.Query;
+import java.util.Collections;
+import java.util.List;
+
+public class TimeMachineConfiguration implements BatchExtension {
+
+  private static final int NUMBER_OF_VARIATION_SNAPSHOTS = 5;
+
+  private Project project;
+  private final Configuration configuration;
+  private List<PastSnapshot> projectPastSnapshots;
+  private DatabaseSession session;
+
+  public TimeMachineConfiguration(DatabaseSession session, Project project, Configuration configuration, PastSnapshotFinder pastSnapshotFinder) {
+    this.session = session;
+    this.project = project;
+    this.configuration = configuration;
+    initPastSnapshots(pastSnapshotFinder);
+  }
+
+  private void initPastSnapshots(PastSnapshotFinder pastSnapshotFinder) {
+    Snapshot projectSnapshot = buildProjectSnapshot();
+
+    projectPastSnapshots = Lists.newLinkedList();
+    if (projectSnapshot != null) {
+      for (int index = 1; index <= NUMBER_OF_VARIATION_SNAPSHOTS; index++) {
+        PastSnapshot pastSnapshot = pastSnapshotFinder.find(projectSnapshot, configuration, index);
+        if (pastSnapshot != null) {
+          log(pastSnapshot);
+          projectPastSnapshots.add(pastSnapshot);
+        }
+      }
+    }
+  }
+
+  private Snapshot buildProjectSnapshot() {
+    Query query = session.createNativeQuery("select p.id from projects p where p.kee=:resourceKey and p.qualifier<>:lib and p.enabled=:enabled");
+    query.setParameter("resourceKey", project.getKey());
+    query.setParameter("lib", Qualifiers.LIBRARY);
+    query.setParameter("enabled", Boolean.TRUE);
+
+    Snapshot snapshot = null;
+    Number projectId = session.getSingleResult(query, null);
+    if (projectId != null) {
+      snapshot = new Snapshot();
+      snapshot.setResourceId(projectId.intValue());
+      snapshot.setCreatedAt(project.getAnalysisDate());
+    }
+    return snapshot;
+  }
+
+  private void log(PastSnapshot pastSnapshot) {
+    String qualifier = pastSnapshot.getQualifier();
+    // hack to avoid too many logs when the views plugin is installed
+    if (StringUtils.equals(Qualifiers.VIEW, qualifier) || StringUtils.equals(Qualifiers.SUBVIEW, qualifier)) {
+      LoggerFactory.getLogger(getClass()).debug(pastSnapshot.toString());
+    } else {
+      Logs.INFO.info(pastSnapshot.toString());
+    }
+  }
+
+  public boolean skipTendencies() {
+    return configuration.getBoolean(CoreProperties.SKIP_TENDENCIES_PROPERTY, CoreProperties.SKIP_TENDENCIES_DEFAULT_VALUE);
+  }
+
+  public int getTendencyPeriodInDays() {
+    return configuration.getInt(CoreProperties.CORE_TENDENCY_DEPTH_PROPERTY, CoreProperties.CORE_TENDENCY_DEPTH_DEFAULT_VALUE);
+  }
+
+  public List<PastSnapshot> getProjectPastSnapshots() {
+    return projectPastSnapshots;
+  }
+
+  public boolean isFileVariationEnabled() {
+    return configuration.getBoolean("sonar.enableFileVariation", Boolean.FALSE);
+  }
+}
diff --git a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersister.java b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersister.java
index 889a9010d78..6021e9ef78c 100644
--- a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersister.java
+++ b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersister.java
@@ -27,7 +27,6 @@ import org.sonar.api.resources.Project;
 import org.sonar.api.resources.Resource;
 import org.sonar.api.resources.ResourceUtils;
 import org.sonar.batch.components.PastSnapshot;
-import org.sonar.batch.components.TimeMachineConfiguration;
 import org.sonar.core.NotDryRun;
 
 import java.util.List;
diff --git a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/VariationDecorator.java b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/VariationDecorator.java
index 1fe3ec56cc1..5299904a13b 100644
--- a/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/VariationDecorator.java
+++ b/plugins/sonar-core-plugin/src/main/java/org/sonar/plugins/core/timemachine/VariationDecorator.java
@@ -22,36 +22,38 @@ package org.sonar.plugins.core.timemachine;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import org.apache.commons.lang.StringUtils;
+import org.sonar.api.CoreProperties;
 import org.sonar.api.batch.*;
 import org.sonar.api.measures.*;
 import org.sonar.api.resources.Project;
+import org.sonar.api.resources.Qualifiers;
 import org.sonar.api.resources.Resource;
 import org.sonar.api.resources.Scopes;
 import org.sonar.batch.components.PastMeasuresLoader;
 import org.sonar.batch.components.PastSnapshot;
-import org.sonar.batch.components.TimeMachineConfiguration;
-import org.sonar.core.NotDryRun;
 
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
-@NotDryRun
 @DependedUpon(DecoratorBarriers.END_OF_TIME_MACHINE)
 public class VariationDecorator implements Decorator {
 
   private List<PastSnapshot> projectPastSnapshots;
   private MetricFinder metricFinder;
   private PastMeasuresLoader pastMeasuresLoader;
+  private final boolean enabledFileVariation;
 
 
   public VariationDecorator(PastMeasuresLoader pastMeasuresLoader, MetricFinder metricFinder, TimeMachineConfiguration configuration) {
-    this(pastMeasuresLoader, metricFinder, configuration.getProjectPastSnapshots());
+    this(pastMeasuresLoader, metricFinder, configuration.getProjectPastSnapshots(), configuration.isFileVariationEnabled());
   }
-  public VariationDecorator(PastMeasuresLoader pastMeasuresLoader, MetricFinder metricFinder, List<PastSnapshot> projectPastSnapshots) {
+
+  VariationDecorator(PastMeasuresLoader pastMeasuresLoader, MetricFinder metricFinder, List<PastSnapshot> projectPastSnapshots, boolean enabledFileVariation) {
     this.pastMeasuresLoader = pastMeasuresLoader;
     this.projectPastSnapshots = projectPastSnapshots;
     this.metricFinder = metricFinder;
+    this.enabledFileVariation = enabledFileVariation;
   }
 
   public boolean shouldExecuteOnProject(Project project) {
@@ -64,19 +66,23 @@ public class VariationDecorator implements Decorator {
   }
 
   public void decorate(Resource resource, DecoratorContext context) {
-    if (shouldCalculateVariations(resource)) {
-      for (PastSnapshot projectPastSnapshot : projectPastSnapshots) {
-        calculateVariation(resource, context, projectPastSnapshot);
+    for (PastSnapshot projectPastSnapshot : projectPastSnapshots) {
+      if (shouldComputeVariation(projectPastSnapshot.getMode(), resource)) {
+        computeVariation(resource, context, projectPastSnapshot);
       }
     }
   }
 
-  static boolean shouldCalculateVariations(Resource resource) {
+  boolean shouldComputeVariation(String variationMode, Resource resource) {
+    if (Scopes.FILE.equals(resource.getScope()) && !Qualifiers.UNIT_TEST_FILE.equals(resource.getQualifier())) {
+      return enabledFileVariation && StringUtils.equals(variationMode, CoreProperties.TIMEMACHINE_MODE_PREVIOUS_ANALYSIS);
+    }
+
     // measures on files are currently purged, so past measures are not available on files
     return StringUtils.equals(Scopes.PROJECT, resource.getScope()) || StringUtils.equals(Scopes.DIRECTORY, resource.getScope());
   }
 
-  private void calculateVariation(Resource resource, DecoratorContext context, PastSnapshot pastSnapshot) {
+  private void computeVariation(Resource resource, DecoratorContext context, PastSnapshot pastSnapshot) {
     List<Object[]> pastMeasures = pastMeasuresLoader.getPastMeasures(resource, pastSnapshot);
     compareWithPastMeasures(context, pastSnapshot.getIndex(), pastMeasures);
   }
diff --git a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/NewViolationsDecoratorTest.java b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/NewViolationsDecoratorTest.java
index 22a239811b3..b027004067b 100644
--- a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/NewViolationsDecoratorTest.java
+++ b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/NewViolationsDecoratorTest.java
@@ -38,7 +38,6 @@ import org.sonar.api.rules.Rule;
 import org.sonar.api.rules.RulePriority;
 import org.sonar.api.rules.Violation;
 import org.sonar.batch.components.PastSnapshot;
-import org.sonar.batch.components.TimeMachineConfiguration;
 
 import java.util.Arrays;
 import java.util.Date;
diff --git a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TendencyDecoratorTest.java b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TendencyDecoratorTest.java
index 9fd3336ab0c..5999463ec21 100644
--- a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TendencyDecoratorTest.java
+++ b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TendencyDecoratorTest.java
@@ -29,7 +29,6 @@ import org.sonar.api.measures.Measure;
 import org.sonar.api.measures.MetricFinder;
 import org.sonar.api.resources.JavaPackage;
 import org.sonar.api.resources.Project;
-import org.sonar.batch.components.TimeMachineConfiguration;
 
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
@@ -61,7 +60,9 @@ public class TendencyDecoratorTest {
   }
 
   private TimeMachineConfiguration newConf() {
-    return new TimeMachineConfiguration(new PropertiesConfiguration());
+    TimeMachineConfiguration configuration = mock(TimeMachineConfiguration.class);
+    when(configuration.getTendencyPeriodInDays()).thenReturn(30);
+    return configuration;
   }
 
   @Test
diff --git a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersisterTest.java b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersisterTest.java
index afc51cf8969..21dcfefffec 100644
--- a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersisterTest.java
+++ b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationPersisterTest.java
@@ -23,7 +23,6 @@ import org.junit.Test;
 import org.sonar.api.database.model.Snapshot;
 import org.sonar.api.utils.DateUtils;
 import org.sonar.batch.components.PastSnapshot;
-import org.sonar.batch.components.TimeMachineConfiguration;
 import org.sonar.jpa.test.AbstractDbUnitTestCase;
 
 import java.text.ParseException;
diff --git a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationTest.java b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationTest.java
index f1444bd6acc..dda4f1a77b8 100644
--- a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationTest.java
+++ b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/TimeMachineConfigurationTest.java
@@ -20,20 +20,19 @@
 package org.sonar.plugins.core.timemachine;
 
 import org.apache.commons.configuration.PropertiesConfiguration;
+import org.hamcrest.BaseMatcher;
+import org.hamcrest.Description;
 import org.junit.Test;
 import org.sonar.api.CoreProperties;
 import org.sonar.api.database.model.Snapshot;
-import org.sonar.api.utils.DateUtils;
-import org.sonar.batch.components.PastSnapshot;
+import org.sonar.api.resources.Project;
 import org.sonar.batch.components.PastSnapshotFinder;
-import org.sonar.batch.components.TimeMachineConfiguration;
 import org.sonar.jpa.test.AbstractDbUnitTestCase;
 
-import java.text.ParseException;
-import java.util.Date;
-
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.mockito.Matchers.argThat;
+import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.*;
 
 public class TimeMachineConfigurationTest extends AbstractDbUnitTestCase {
@@ -42,32 +41,41 @@ public class TimeMachineConfigurationTest extends AbstractDbUnitTestCase {
   public void shouldSkipTendencies() {
     PropertiesConfiguration conf = new PropertiesConfiguration();
     conf.setProperty(CoreProperties.SKIP_TENDENCIES_PROPERTY, true);
-    assertThat(new TimeMachineConfiguration(conf).skipTendencies(), is(true));
+    assertThat(new TimeMachineConfiguration(getSession(), new Project("my:project"), conf, mock(PastSnapshotFinder.class)).skipTendencies(), is(true));
   }
 
   @Test
   public void shouldNotSkipTendenciesByDefault() {
     PropertiesConfiguration conf = new PropertiesConfiguration();
-    assertThat(new TimeMachineConfiguration(conf).skipTendencies(), is(false));
+    assertThat(new TimeMachineConfiguration(getSession(), new Project("my:project"), conf, mock(PastSnapshotFinder.class)).skipTendencies(), is(false));
   }
 
   @Test
-  public void shouldInitPastSnapshots() throws ParseException {
+  public void shouldInitPastSnapshots() {
+    setupData("shared");
     PropertiesConfiguration conf = new PropertiesConfiguration();
     PastSnapshotFinder pastSnapshotFinder = mock(PastSnapshotFinder.class);
-    when(pastSnapshotFinder.find(null, conf, 1)).thenReturn(new PastSnapshot("days", new Date(), newSnapshot("2010-10-15")));
-    when(pastSnapshotFinder.find(null, conf, 3)).thenReturn(new PastSnapshot("days", new Date(), newSnapshot("2010-10-13")));
 
-    TimeMachineConfiguration timeMachineConfiguration = new TimeMachineConfiguration(conf, pastSnapshotFinder, null);
+    new TimeMachineConfiguration(getSession(), new Project("my:project"), conf, pastSnapshotFinder);
 
-    verify(pastSnapshotFinder).find(null, conf, 1);
-    verify(pastSnapshotFinder).find(null, conf, 2);
-    verify(pastSnapshotFinder).find(null, conf, 3);
+    verify(pastSnapshotFinder).find(argThat(new BaseMatcher<Snapshot>() {
+      public boolean matches(Object o) {
+        return ((Snapshot) o).getResourceId() == 2 /* see database in shared.xml */;
+      }
 
-    assertThat(timeMachineConfiguration.getProjectPastSnapshots().size(), is(2));
+      public void describeTo(Description description) {
+      }
+    }), eq(conf), eq(1));
   }
 
-  private Snapshot newSnapshot(String date) throws ParseException {
-    return new Snapshot().setCreatedAt(DateUtils.parseDate(date));
+  @Test
+  public void shouldNotInitPastSnapshotsIfFirstAnalysis() {
+    setupData("shared");
+    PropertiesConfiguration conf = new PropertiesConfiguration();
+    PastSnapshotFinder pastSnapshotFinder = mock(PastSnapshotFinder.class);
+
+    new TimeMachineConfiguration(getSession(), new Project("new:project"), conf, pastSnapshotFinder);
+
+    verifyZeroInteractions(pastSnapshotFinder);
   }
 }
diff --git a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/VariationDecoratorTest.java b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/VariationDecoratorTest.java
index ad4fd12459e..27c2fff471b 100644
--- a/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/VariationDecoratorTest.java
+++ b/plugins/sonar-core-plugin/src/test/java/org/sonar/plugins/core/timemachine/VariationDecoratorTest.java
@@ -21,9 +21,9 @@ package org.sonar.plugins.core.timemachine;
 
 import org.junit.Test;
 import org.mockito.Matchers;
+import org.sonar.api.CoreProperties;
 import org.sonar.api.batch.DecoratorContext;
 import org.sonar.api.database.model.MeasureModel;
-import org.sonar.api.database.model.Snapshot;
 import org.sonar.api.measures.Measure;
 import org.sonar.api.measures.MeasuresFilter;
 import org.sonar.api.measures.Metric;
@@ -50,14 +50,41 @@ public class VariationDecoratorTest extends AbstractDbUnitTestCase {
   public static final Metric COVERAGE = new Metric("coverage").setId(COVERAGE_ID);
 
   @Test
-  public void shouldNotCalculateVariationsOnFiles() {
-    assertThat(VariationDecorator.shouldCalculateVariations(new Project("foo")), is(true));
-    assertThat(VariationDecorator.shouldCalculateVariations(new JavaPackage("org.foo")), is(true));
-    assertThat(VariationDecorator.shouldCalculateVariations(new Directory("org/foo")), is(true));
-
-    assertThat(VariationDecorator.shouldCalculateVariations(new JavaFile("org.foo.Bar")), is(false));
-    assertThat(VariationDecorator.shouldCalculateVariations(new JavaFile("org.foo.Bar", true)), is(false));
-    assertThat(VariationDecorator.shouldCalculateVariations(new File("org/foo/Bar.php")), is(false));
+  public void shouldComputeVariations() {
+    TimeMachineConfiguration conf = mock(TimeMachineConfiguration.class);
+    when(conf.isFileVariationEnabled()).thenReturn(false);
+    VariationDecorator decorator = new VariationDecorator(mock(PastMeasuresLoader.class), mock(MetricFinder.class), conf);
+
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_ANALYSIS, new Project("foo")), is(true));
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_DATE, new Project("foo")), is(true));
+  }
+
+  @Test
+  public void shouldNotComputeFileVariations() {
+    TimeMachineConfiguration conf = mock(TimeMachineConfiguration.class);
+    when(conf.isFileVariationEnabled()).thenReturn(false);
+    VariationDecorator decorator = new VariationDecorator(mock(PastMeasuresLoader.class), mock(MetricFinder.class), conf);
+
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_ANALYSIS, new JavaFile("org.foo.Bar")), is(false));
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_DATE, new JavaFile("org.foo.Bar")), is(false));
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_ANALYSIS, new File("org/foo/Bar.php")), is(false));
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_DATE, new File("org/foo/Bar.php")), is(false));
+  }
+
+  @Test
+  public void shouldComputeFileVariationsIfExplictlyEnabled() {
+    TimeMachineConfiguration conf = mock(TimeMachineConfiguration.class);
+    when(conf.isFileVariationEnabled()).thenReturn(true);
+    VariationDecorator decorator = new VariationDecorator(mock(PastMeasuresLoader.class), mock(MetricFinder.class), conf);
+
+    // only for variation with reference analysis
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_ANALYSIS, new JavaFile("org.foo.Bar")), is(true));
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_DATE, new JavaFile("org.foo.Bar")), is(false));
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_ANALYSIS, new File("org/foo/Bar.php")), is(true));
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_DATE, new File("org/foo/Bar.php")), is(false));
+
+    // no side-effect on other resources
+    assertThat(decorator.shouldComputeVariation(CoreProperties.TIMEMACHINE_MODE_PREVIOUS_ANALYSIS, new Project("foo")), is(true));
   }
 
   @Test
@@ -83,8 +110,7 @@ public class VariationDecoratorTest extends AbstractDbUnitTestCase {
     Measure currentCoverage = newMeasure(COVERAGE, 80.0);
     when(context.getMeasures(Matchers.<MeasuresFilter>anyObject())).thenReturn(Arrays.asList(currentNcloc, currentCoverage));
 
-    VariationDecorator decorator = new VariationDecorator(pastMeasuresLoader, mock(MetricFinder.class),
-        Arrays.asList(pastSnapshot1, pastSnapshot3));
+    VariationDecorator decorator = new VariationDecorator(pastMeasuresLoader, mock(MetricFinder.class), Arrays.asList(pastSnapshot1, pastSnapshot3), false);
     decorator.decorate(javaPackage, context);
 
     // context updated for each variation : 2 times for ncloc and 1 time for coverage
diff --git a/plugins/sonar-core-plugin/src/test/resources/org/sonar/plugins/core/timemachine/TimeMachineConfigurationTest/shared.xml b/plugins/sonar-core-plugin/src/test/resources/org/sonar/plugins/core/timemachine/TimeMachineConfigurationTest/shared.xml
new file mode 100644
index 00000000000..5e53bd405e7
--- /dev/null
+++ b/plugins/sonar-core-plugin/src/test/resources/org/sonar/plugins/core/timemachine/TimeMachineConfigurationTest/shared.xml
@@ -0,0 +1,12 @@
+<dataset>
+
+  <projects long_name="[null]" id="1" scope="PRJ" kee="my:project" qualifier="LIB" name="my project as lib"
+            root_id="[null]" description="[null]" enabled="true" profile_id="[null]" language="java" copy_resource_id="[null]"/>
+
+  <projects long_name="[null]" id="2" scope="PRJ" kee="my:project" qualifier="TRK" name="my project"
+            root_id="[null]" description="[null]" enabled="true" profile_id="[null]" language="java" copy_resource_id="[null]"/>
+
+  <projects long_name="[null]" id="3" scope="DIR" kee="my:project:path/to/dir" qualifier="TRK" name="my dir"
+            root_id="2" description="[null]" enabled="true" profile_id="[null]" language="java" copy_resource_id="[null]"/>
+
+</dataset>