SONAR-15686 Files provided are restricted when PR for selected sensors

24 files changed, 541 insertions, 67 deletions

diff --git a/sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/fs/internal/predicates/ChangedFilePredicate.java b/sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/fs/internal/predicates/ChangedFilePredicate.java
new file mode 100644
index 00000000000..08736a7e61d
--- /dev/null
+++ b/sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/fs/internal/predicates/ChangedFilePredicate.java
@@ -0,0 +1,38 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2021 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.api.batch.fs.internal.predicates;
+
+import org.sonar.api.batch.fs.FilePredicate;
+import org.sonar.api.batch.fs.InputFile;
+
+public class ChangedFilePredicate implements FilePredicate {
+
+  private final FilePredicate originalPredicate;
+
+  public ChangedFilePredicate(FilePredicate originalPredicate) {
+    this.originalPredicate = originalPredicate;
+  }
+
+  @Override
+  public boolean apply(InputFile inputFile) {
+    return originalPredicate.apply(inputFile) && InputFile.Status.SAME != inputFile.status();
+  }
+
+}
diff --git a/sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptor.java b/sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptor.java
index ee5ced6886b..e0819050190 100644
--- a/sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptor.java
+++ b/sonar-plugin-api-impl/src/main/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptor.java
@@ -21,13 +21,23 @@ package org.sonar.api.batch.sensor.internal;
 
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.Set;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import javax.annotation.Nullable;
 import org.sonar.api.batch.fs.InputFile;
 import org.sonar.api.batch.sensor.SensorDescriptor;
 import org.sonar.api.config.Configuration;
 
 public class DefaultSensorDescriptor implements SensorDescriptor {
+  public static final Set<String> SENSORS_ONLY_CHANGED_IN_PR = Collections.unmodifiableSet(Stream.of(
+    "CSS Metrics",
+    "CSS Rules",
+    "HTML",
+    "XML Sensor"
+  ).collect(Collectors.toSet()));
 
   private String name;
   private String[] languages = new String[0];
@@ -35,6 +45,7 @@ public class DefaultSensorDescriptor implements SensorDescriptor {
   private String[] ruleRepositories = new String[0];
   private boolean global = false;
   private Predicate<Configuration> configurationPredicate;
+  private boolean onlyChangedFilesInPullRequests = false;
 
   public String name() {
     return name;
@@ -61,8 +72,16 @@ public class DefaultSensorDescriptor implements SensorDescriptor {
     return global;
   }
 
+  public boolean onlyChangedFilesInPullRequest() {
+    return onlyChangedFilesInPullRequests;
+  }
+
   @Override
   public DefaultSensorDescriptor name(String name) {
+    // TODO: Add onlyChangedFilesInPullRequest into API and implement it at sensors
+    if (SENSORS_ONLY_CHANGED_IN_PR.contains(name)) {
+      onlyChangedFilesInPullRequests = true;
+    }
     this.name = name;
     return this;
   }
diff --git a/sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/fs/internal/predicates/ChangedFilePredicateTest.java b/sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/fs/internal/predicates/ChangedFilePredicateTest.java
new file mode 100644
index 00000000000..f3fcd9309a2
--- /dev/null
+++ b/sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/fs/internal/predicates/ChangedFilePredicateTest.java
@@ -0,0 +1,94 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2021 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.api.batch.fs.internal.predicates;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+import org.sonar.api.batch.fs.FilePredicate;
+import org.sonar.api.batch.fs.InputFile;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class ChangedFilePredicateTest {
+
+  private final FilePredicate predicate = mock(FilePredicate.class);
+  private final InputFile inputFile = mock(InputFile.class);
+
+  private final ChangedFilePredicate underTest = new ChangedFilePredicate(predicate);
+
+  @Test
+  public void apply_when_file_is_changed_and_predicate_is_true() {
+    when(inputFile.status()).thenReturn(InputFile.Status.CHANGED);
+    when(predicate.apply(inputFile)).thenReturn(true);
+
+    Assertions.assertThat(underTest.apply(inputFile)).isTrue();
+
+    verify(predicate, times(1)).apply(any());
+    verify(inputFile, times(1)).status();
+  }
+
+  @Test
+  public void apply_when_file_is_added_and_predicate_is_true() {
+    when(inputFile.status()).thenReturn(InputFile.Status.ADDED);
+    when(predicate.apply(inputFile)).thenReturn(true);
+
+    Assertions.assertThat(underTest.apply(inputFile)).isTrue();
+
+    verify(predicate, times(1)).apply(any());
+    verify(inputFile, times(1)).status();
+  }
+
+  @Test
+  public void do_not_apply_when_file_is_same_and_predicate_is_true() {
+    when(inputFile.status()).thenReturn(InputFile.Status.SAME);
+    when(predicate.apply(inputFile)).thenReturn(true);
+
+    Assertions.assertThat(underTest.apply(inputFile)).isFalse();
+
+    verify(predicate, times(1)).apply(any());
+    verify(inputFile, times(1)).status();
+  }
+
+  @Test
+  public void predicate_is_evaluated_before_file_status() {
+    when(predicate.apply(inputFile)).thenReturn(false);
+
+    Assertions.assertThat(underTest.apply(inputFile)).isFalse();
+
+    verify(inputFile, never()).status();
+  }
+
+  @Test
+  public void do_not_apply_when_file_is_same_and_predicate_is_false() {
+    when(inputFile.status()).thenReturn(InputFile.Status.SAME);
+    when(predicate.apply(inputFile)).thenReturn(true);
+
+    Assertions.assertThat(underTest.apply(inputFile)).isFalse();
+
+    verify(predicate, times(1)).apply(any());
+    verify(inputFile, times(1)).status();
+  }
+
+}
diff --git a/sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptorTest.java b/sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptorTest.java
index ac6c72c24dd..e34c5385cad 100644
--- a/sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptorTest.java
+++ b/sonar-plugin-api-impl/src/test/java/org/sonar/api/batch/sensor/internal/DefaultSensorDescriptorTest.java
@@ -19,12 +19,17 @@
  */
 package org.sonar.api.batch.sensor.internal;
 
+import com.tngtech.java.junit.dataprovider.DataProvider;
+import com.tngtech.java.junit.dataprovider.DataProviderRunner;
+import com.tngtech.java.junit.dataprovider.UseDataProvider;
 import org.junit.Test;
+import org.junit.runner.RunWith;
 import org.sonar.api.batch.fs.InputFile;
 import org.sonar.api.config.internal.MapSettings;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+@RunWith(DataProviderRunner.class)
 public class DefaultSensorDescriptorTest {
 
   @Test
@@ -48,4 +53,29 @@ public class DefaultSensorDescriptorTest {
     assertThat(descriptor.ruleRepositories()).containsOnly("squid-java");
   }
 
+  @Test
+  @UseDataProvider("sensorsOnlyChangedInPR")
+  public void describe_with_restricted_sensor(String sensorName) {
+    DefaultSensorDescriptor descriptor = new DefaultSensorDescriptor();
+    descriptor
+      .name(sensorName);
+
+    assertThat(descriptor.onlyChangedFilesInPullRequest()).isTrue();
+  }
+
+  @Test
+  @UseDataProvider("sensorsOnlyChangedInPR")
+  public void describe_with_non_restricted_sensor(String sensorName) {
+    DefaultSensorDescriptor descriptor = new DefaultSensorDescriptor();
+    descriptor
+      .name(sensorName + "other");
+
+    assertThat(descriptor.onlyChangedFilesInPullRequest()).isFalse();
+  }
+
+  @DataProvider
+  public static Object[][] sensorsOnlyChangedInPR() {
+    return new Object[][] {DefaultSensorDescriptor.SENSORS_ONLY_CHANGED_IN_PR.toArray()};
+  }
+
 }
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/AbstractExtensionDictionnary.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/AbstractExtensionDictionary.java
index bd56e76433b..a165751f2ce 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/AbstractExtensionDictionnary.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/AbstractExtensionDictionary.java
@@ -37,11 +37,11 @@ import org.sonar.api.utils.AnnotationUtils;
 import org.sonar.api.utils.dag.DirectAcyclicGraph;
 import org.sonar.core.platform.ComponentContainer;
 
-public abstract class AbstractExtensionDictionnary {
+public abstract class AbstractExtensionDictionary {
 
   private final ComponentContainer componentContainer;
 
-  public AbstractExtensionDictionnary(ComponentContainer componentContainer) {
+  public AbstractExtensionDictionary(ComponentContainer componentContainer) {
     this.componentContainer = componentContainer;
   }
 
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionnary.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionary.java
index b647355a7a1..562792646fe 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionnary.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionary.java
@@ -27,12 +27,12 @@ import org.sonar.core.platform.ComponentContainer;
 import org.sonar.scanner.postjob.PostJobOptimizer;
 import org.sonar.scanner.postjob.PostJobWrapper;
 
-public class PostJobExtensionDictionnary extends AbstractExtensionDictionnary {
+public class PostJobExtensionDictionary extends AbstractExtensionDictionary {
 
   private final PostJobContext postJobContext;
   private final PostJobOptimizer postJobOptimizer;
 
-  public PostJobExtensionDictionnary(ComponentContainer componentContainer, PostJobOptimizer postJobOptimizer, PostJobContext postJobContext) {
+  public PostJobExtensionDictionary(ComponentContainer componentContainer, PostJobOptimizer postJobOptimizer, PostJobContext postJobContext) {
     super(componentContainer);
     this.postJobOptimizer = postJobOptimizer;
     this.postJobContext = postJobContext;
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/postjob/PostJobsExecutor.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/postjob/PostJobsExecutor.java
index 098fdea74ff..21486a39536 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/postjob/PostJobsExecutor.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/postjob/PostJobsExecutor.java
@@ -23,14 +23,14 @@ import java.util.Collection;
 import java.util.stream.Collectors;
 import org.sonar.api.utils.log.Logger;
 import org.sonar.api.utils.log.Loggers;
-import org.sonar.scanner.bootstrap.PostJobExtensionDictionnary;
+import org.sonar.scanner.bootstrap.PostJobExtensionDictionary;
 
 public class PostJobsExecutor {
   private static final Logger LOG = Loggers.get(PostJobsExecutor.class);
 
-  private final PostJobExtensionDictionnary selector;
+  private final PostJobExtensionDictionary selector;
 
-  public PostJobsExecutor(PostJobExtensionDictionnary selector) {
+  public PostJobsExecutor(PostJobExtensionDictionary selector) {
     this.selector = selector;
   }
 
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ModuleScanContainer.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ModuleScanContainer.java
index e67d65da9f1..3ab08728bbd 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ModuleScanContainer.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ModuleScanContainer.java
@@ -26,7 +26,7 @@ import org.sonar.scanner.bootstrap.ExtensionInstaller;
 import org.sonar.scanner.scan.filesystem.DefaultModuleFileSystem;
 import org.sonar.scanner.scan.filesystem.ModuleInputComponentStore;
 import org.sonar.scanner.sensor.ModuleSensorContext;
-import org.sonar.scanner.sensor.ModuleSensorExtensionDictionnary;
+import org.sonar.scanner.sensor.ModuleSensorExtensionDictionary;
 import org.sonar.scanner.sensor.ModuleSensorOptimizer;
 import org.sonar.scanner.sensor.ModuleSensorsExecutor;
 
@@ -65,7 +65,7 @@ public class ModuleScanContainer extends ComponentContainer {
       ModuleSensorOptimizer.class,
 
       ModuleSensorContext.class,
-      ModuleSensorExtensionDictionnary.class
+      ModuleSensorExtensionDictionary.class
     );
   }
 
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ProjectScanContainer.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ProjectScanContainer.java
index d77df0452ee..94c44b23a73 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ProjectScanContainer.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/ProjectScanContainer.java
@@ -41,7 +41,7 @@ import org.sonar.scanner.analysis.AnalysisTempFolderProvider;
 import org.sonar.scanner.bootstrap.ExtensionInstaller;
 import org.sonar.scanner.bootstrap.ExtensionMatcher;
 import org.sonar.scanner.bootstrap.GlobalAnalysisMode;
-import org.sonar.scanner.bootstrap.PostJobExtensionDictionnary;
+import org.sonar.scanner.bootstrap.PostJobExtensionDictionary;
 import org.sonar.scanner.ci.CiConfigurationProvider;
 import org.sonar.scanner.ci.vendors.AppVeyor;
 import org.sonar.scanner.ci.vendors.AwsCodeBuild;
@@ -126,7 +126,7 @@ import org.sonar.scanner.scm.ScmPublisher;
 import org.sonar.scanner.scm.ScmRevisionImpl;
 import org.sonar.scanner.sensor.DefaultSensorStorage;
 import org.sonar.scanner.sensor.ProjectSensorContext;
-import org.sonar.scanner.sensor.ProjectSensorExtensionDictionnary;
+import org.sonar.scanner.sensor.ProjectSensorExtensionDictionary;
 import org.sonar.scanner.sensor.ProjectSensorOptimizer;
 import org.sonar.scanner.sensor.ProjectSensorsExecutor;
 import org.sonar.scm.git.GitScmSupport;
@@ -256,7 +256,7 @@ public class ProjectScanContainer extends ComponentContainer {
       PostJobsExecutor.class,
       PostJobOptimizer.class,
       DefaultPostJobContext.class,
-      PostJobExtensionDictionnary.class,
+      PostJobExtensionDictionary.class,
 
       // SCM
       ScmConfiguration.class,
@@ -269,7 +269,7 @@ public class ProjectScanContainer extends ComponentContainer {
       ProjectSensorContext.class,
       ProjectSensorOptimizer.class,
       ProjectSensorsExecutor.class,
-      ProjectSensorExtensionDictionnary.class,
+      ProjectSensorExtensionDictionary.class,
 
       // Filesystem
       DefaultProjectFileSystem.class,
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultModuleFileSystem.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultModuleFileSystem.java
index d7b4a93d3ff..fb5263d8d03 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultModuleFileSystem.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultModuleFileSystem.java
@@ -19,11 +19,10 @@
  */
 package org.sonar.scanner.scan.filesystem;
 
-import org.sonar.api.batch.fs.internal.DefaultFileSystem;
 import org.sonar.api.batch.fs.internal.DefaultInputModule;
 import org.sonar.api.batch.fs.internal.predicates.DefaultFilePredicates;
 
-public class DefaultModuleFileSystem extends DefaultFileSystem {
+public class DefaultModuleFileSystem extends MutableFileSystem {
 
   public DefaultModuleFileSystem(ModuleInputComponentStore moduleInputFileCache, DefaultInputModule module) {
     super(module.getBaseDir(), moduleInputFileCache, new DefaultFilePredicates(module.getBaseDir()));
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultProjectFileSystem.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultProjectFileSystem.java
index fb5082bdefa..1f3a5c1c128 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultProjectFileSystem.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/DefaultProjectFileSystem.java
@@ -19,11 +19,10 @@
  */
 package org.sonar.scanner.scan.filesystem;
 
-import org.sonar.api.batch.fs.internal.DefaultFileSystem;
 import org.sonar.api.batch.fs.internal.DefaultInputProject;
 import org.sonar.api.batch.fs.internal.predicates.DefaultFilePredicates;
 
-public class DefaultProjectFileSystem extends DefaultFileSystem {
+public class DefaultProjectFileSystem extends MutableFileSystem {
 
   public DefaultProjectFileSystem(InputComponentStore inputComponentStore, DefaultInputProject project) {
     super(project.getBaseDir(), inputComponentStore, new DefaultFilePredicates(project.getBaseDir()));
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/MutableFileSystem.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/MutableFileSystem.java
new file mode 100644
index 00000000000..f17b15eb394
--- /dev/null
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/scan/filesystem/MutableFileSystem.java
@@ -0,0 +1,59 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2021 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.scanner.scan.filesystem;
+
+import java.nio.file.Path;
+import org.sonar.api.batch.fs.FilePredicate;
+import org.sonar.api.batch.fs.FilePredicates;
+import org.sonar.api.batch.fs.InputFile;
+import org.sonar.api.batch.fs.internal.DefaultFileSystem;
+import org.sonar.api.batch.fs.internal.predicates.ChangedFilePredicate;
+
+public class MutableFileSystem extends DefaultFileSystem {
+  private boolean restrictToChangedFiles = false;
+
+  public MutableFileSystem(Path baseDir, Cache cache, FilePredicates filePredicates) {
+    super(baseDir, cache, filePredicates);
+  }
+
+  public MutableFileSystem(Path baseDir) {
+    super(baseDir);
+  }
+
+  @Override
+  public Iterable<InputFile> inputFiles(FilePredicate requestPredicate) {
+    if (restrictToChangedFiles) {
+      return super.inputFiles(new ChangedFilePredicate(requestPredicate));
+    }
+    return super.inputFiles(requestPredicate);
+  }
+
+  @Override
+  public InputFile inputFile(FilePredicate requestPredicate) {
+    if (restrictToChangedFiles) {
+      return super.inputFile(new ChangedFilePredicate(requestPredicate));
+    }
+    return super.inputFile(requestPredicate);
+  }
+
+  public void setRestrictToChangedFiles(boolean restrictToChangedFiles) {
+    this.restrictToChangedFiles = restrictToChangedFiles;
+  }
+}
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/AbstractSensorWrapper.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/AbstractSensorWrapper.java
index 404bf73dfa2..21e5308d66e 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/AbstractSensorWrapper.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/AbstractSensorWrapper.java
@@ -22,18 +22,29 @@ package org.sonar.scanner.sensor;
 import org.sonar.api.batch.sensor.SensorContext;
 import org.sonar.api.batch.sensor.internal.DefaultSensorDescriptor;
 import org.sonar.api.scanner.sensor.ProjectSensor;
+import org.sonar.api.utils.log.Logger;
+import org.sonar.api.utils.log.Loggers;
+import org.sonar.scanner.scan.branch.BranchConfiguration;
+import org.sonar.scanner.scan.branch.BranchType;
+import org.sonar.scanner.scan.filesystem.MutableFileSystem;
 
 public abstract class AbstractSensorWrapper<G extends ProjectSensor> {
+  private static final Logger LOGGER = Loggers.get(AbstractSensorWrapper.class);
+
   private final G wrappedSensor;
   private final SensorContext context;
+  private final MutableFileSystem fileSystem;
   private final DefaultSensorDescriptor descriptor;
   private final AbstractSensorOptimizer optimizer;
+  private final boolean isPullRequest;
 
-  public AbstractSensorWrapper(G sensor, SensorContext context, AbstractSensorOptimizer optimizer) {
+  public AbstractSensorWrapper(G sensor, SensorContext context, AbstractSensorOptimizer optimizer, MutableFileSystem fileSystem, BranchConfiguration branchConfiguration) {
     this.wrappedSensor = sensor;
     this.optimizer = optimizer;
     this.context = context;
     this.descriptor = new DefaultSensorDescriptor();
+    this.fileSystem = fileSystem;
+    this.isPullRequest = branchConfiguration.branchType() == BranchType.PULL_REQUEST;
     sensor.describe(this.descriptor);
     if (descriptor.name() == null) {
       descriptor.name(sensor.getClass().getName());
@@ -45,6 +56,11 @@ public abstract class AbstractSensorWrapper<G extends ProjectSensor> {
   }
 
   public void analyse() {
+    boolean sensorIsRestricted = descriptor.onlyChangedFilesInPullRequest() && isPullRequest;
+    if (sensorIsRestricted) {
+      LOGGER.info("Sensor {} is restricted to changed files only", descriptor.name());
+    }
+    fileSystem.setRestrictToChangedFiles(sensorIsRestricted);
     wrappedSensor.execute(context);
   }
 
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorExtensionDictionnary.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorExtensionDictionary.java
index 734ebb9192a..3df2f067fbc 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorExtensionDictionnary.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorExtensionDictionary.java
@@ -23,23 +23,30 @@ import java.util.Collection;
 import java.util.stream.Collectors;
 import org.sonar.api.batch.sensor.Sensor;
 import org.sonar.core.platform.ComponentContainer;
-import org.sonar.scanner.bootstrap.AbstractExtensionDictionnary;
+import org.sonar.scanner.bootstrap.AbstractExtensionDictionary;
+import org.sonar.scanner.scan.branch.BranchConfiguration;
+import org.sonar.scanner.scan.filesystem.MutableFileSystem;
 
-public class ModuleSensorExtensionDictionnary extends AbstractExtensionDictionnary {
+public class ModuleSensorExtensionDictionary extends AbstractExtensionDictionary {
 
   private final ModuleSensorContext sensorContext;
   private final ModuleSensorOptimizer sensorOptimizer;
+  private final MutableFileSystem fileSystem;
+  private final BranchConfiguration branchConfiguration;
 
-  public ModuleSensorExtensionDictionnary(ComponentContainer componentContainer, ModuleSensorContext sensorContext, ModuleSensorOptimizer sensorOptimizer) {
+  public ModuleSensorExtensionDictionary(ComponentContainer componentContainer, ModuleSensorContext sensorContext, ModuleSensorOptimizer sensorOptimizer,
+    MutableFileSystem fileSystem, BranchConfiguration branchConfiguration) {
     super(componentContainer);
     this.sensorContext = sensorContext;
     this.sensorOptimizer = sensorOptimizer;
+    this.fileSystem = fileSystem;
+    this.branchConfiguration = branchConfiguration;
   }
 
   public Collection<ModuleSensorWrapper> selectSensors(boolean global) {
     Collection<Sensor> result = sort(getFilteredExtensions(Sensor.class, null));
     return result.stream()
-      .map(s -> new ModuleSensorWrapper(s, sensorContext, sensorOptimizer))
+      .map(s -> new ModuleSensorWrapper(s, sensorContext, sensorOptimizer, fileSystem, branchConfiguration))
       .filter(s -> global == s.isGlobal() && s.shouldExecute())
       .collect(Collectors.toList());
   }
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorWrapper.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorWrapper.java
index 4fbd1eae629..31c28b78a07 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorWrapper.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorWrapper.java
@@ -20,10 +20,12 @@
 package org.sonar.scanner.sensor;
 
 import org.sonar.api.batch.sensor.Sensor;
+import org.sonar.scanner.scan.branch.BranchConfiguration;
+import org.sonar.scanner.scan.filesystem.MutableFileSystem;
 
 public class ModuleSensorWrapper extends AbstractSensorWrapper<Sensor> {
 
-  public ModuleSensorWrapper(Sensor sensor, ModuleSensorContext context, ModuleSensorOptimizer optimizer) {
-    super(sensor, context, optimizer);
+  public ModuleSensorWrapper(Sensor sensor, ModuleSensorContext context, ModuleSensorOptimizer optimizer, MutableFileSystem fileSystem, BranchConfiguration branchConfiguration) {
+    super(sensor, context, optimizer, fileSystem, branchConfiguration);
   }
 }
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorsExecutor.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorsExecutor.java
index 6b5d59b57cb..4cfa093133b 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorsExecutor.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ModuleSensorsExecutor.java
@@ -34,12 +34,12 @@ import org.sonar.scanner.fs.InputModuleHierarchy;
 public class ModuleSensorsExecutor {
   private static final Logger LOG = Loggers.get(ModuleSensorsExecutor.class);
   private static final Profiler profiler = Profiler.create(LOG);
-  private final ModuleSensorExtensionDictionnary selector;
+  private final ModuleSensorExtensionDictionary selector;
   private final SensorStrategy strategy;
   private final ScannerPluginRepository pluginRepo;
   private final boolean isRoot;
 
-  public ModuleSensorsExecutor(ModuleSensorExtensionDictionnary selector, DefaultInputModule module, InputModuleHierarchy hierarchy,
+  public ModuleSensorsExecutor(ModuleSensorExtensionDictionary selector, DefaultInputModule module, InputModuleHierarchy hierarchy,
     SensorStrategy strategy, ScannerPluginRepository pluginRepo) {
     this.selector = selector;
     this.strategy = strategy;
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorExtensionDictionnary.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorExtensionDictionary.java
index 00c47e17bde..44180231a10 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorExtensionDictionnary.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorExtensionDictionary.java
@@ -24,23 +24,30 @@ import java.util.List;
 import java.util.stream.Collectors;
 import org.sonar.api.scanner.sensor.ProjectSensor;
 import org.sonar.core.platform.ComponentContainer;
-import org.sonar.scanner.bootstrap.AbstractExtensionDictionnary;
+import org.sonar.scanner.bootstrap.AbstractExtensionDictionary;
+import org.sonar.scanner.scan.branch.BranchConfiguration;
+import org.sonar.scanner.scan.filesystem.MutableFileSystem;
 
-public class ProjectSensorExtensionDictionnary extends AbstractExtensionDictionnary {
+public class ProjectSensorExtensionDictionary extends AbstractExtensionDictionary {
 
   private final ProjectSensorContext sensorContext;
   private final ProjectSensorOptimizer sensorOptimizer;
+  private final MutableFileSystem fileSystem;
+  private final BranchConfiguration branchConfiguration;
 
-  public ProjectSensorExtensionDictionnary(ComponentContainer componentContainer, ProjectSensorContext sensorContext, ProjectSensorOptimizer sensorOptimizer) {
+  public ProjectSensorExtensionDictionary(ComponentContainer componentContainer, ProjectSensorContext sensorContext, ProjectSensorOptimizer sensorOptimizer,
+    MutableFileSystem fileSystem, BranchConfiguration branchConfiguration) {
     super(componentContainer);
     this.sensorContext = sensorContext;
     this.sensorOptimizer = sensorOptimizer;
+    this.fileSystem = fileSystem;
+    this.branchConfiguration = branchConfiguration;
   }
 
   public List<ProjectSensorWrapper> selectSensors() {
     Collection<ProjectSensor> result = sort(getFilteredExtensions(ProjectSensor.class, null));
     return result.stream()
-      .map(s -> new ProjectSensorWrapper(s, sensorContext, sensorOptimizer))
+      .map(s -> new ProjectSensorWrapper(s, sensorContext, sensorOptimizer, fileSystem, branchConfiguration))
       .filter(ProjectSensorWrapper::shouldExecute)
       .collect(Collectors.toList());
   }
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorWrapper.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorWrapper.java
index d56c733c60c..24e5dc483e9 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorWrapper.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorWrapper.java
@@ -20,11 +20,14 @@
 package org.sonar.scanner.sensor;
 
 import org.sonar.api.scanner.sensor.ProjectSensor;
+import org.sonar.scanner.scan.branch.BranchConfiguration;
+import org.sonar.scanner.scan.filesystem.MutableFileSystem;
 
 public class ProjectSensorWrapper extends AbstractSensorWrapper<ProjectSensor> {
 
-  public ProjectSensorWrapper(ProjectSensor sensor, ProjectSensorContext context, ProjectSensorOptimizer optimizer) {
-    super(sensor, context, optimizer);
+  public ProjectSensorWrapper(ProjectSensor sensor, ProjectSensorContext context, ProjectSensorOptimizer optimizer,
+    MutableFileSystem fileSystem, BranchConfiguration branchConfiguration) {
+    super(sensor, context, optimizer, fileSystem, branchConfiguration);
   }
 
 }
diff --git a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorsExecutor.java b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorsExecutor.java
index 81ba19409b6..6af61c7c74b 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorsExecutor.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/scanner/sensor/ProjectSensorsExecutor.java
@@ -29,10 +29,10 @@ import org.sonar.scanner.bootstrap.ScannerPluginRepository;
 public class ProjectSensorsExecutor {
   private static final Logger LOG = Loggers.get(ProjectSensorsExecutor.class);
   private static final Profiler profiler = Profiler.create(LOG);
-  private final ProjectSensorExtensionDictionnary selector;
+  private final ProjectSensorExtensionDictionary selector;
   private final ScannerPluginRepository pluginRepo;
 
-  public ProjectSensorsExecutor(ProjectSensorExtensionDictionnary selector, ScannerPluginRepository pluginRepo) {
+  public ProjectSensorsExecutor(ProjectSensorExtensionDictionary selector, ScannerPluginRepository pluginRepo) {
     this.selector = selector;
     this.pluginRepo = pluginRepo;
   }
diff --git a/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/ModuleSensorExtensionDictionnaryTest.java b/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/ModuleSensorExtensionDictionaryTest.java
index 61481a22cdc..a539b0b51d3 100644
--- a/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/ModuleSensorExtensionDictionnaryTest.java
+++ b/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/ModuleSensorExtensionDictionaryTest.java
@@ -35,8 +35,10 @@ import org.sonar.api.batch.sensor.SensorContext;
 import org.sonar.api.batch.sensor.SensorDescriptor;
 import org.sonar.api.batch.sensor.internal.DefaultSensorDescriptor;
 import org.sonar.core.platform.ComponentContainer;
+import org.sonar.scanner.scan.branch.BranchConfiguration;
+import org.sonar.scanner.scan.filesystem.MutableFileSystem;
 import org.sonar.scanner.sensor.ModuleSensorContext;
-import org.sonar.scanner.sensor.ModuleSensorExtensionDictionnary;
+import org.sonar.scanner.sensor.ModuleSensorExtensionDictionary;
 import org.sonar.scanner.sensor.ModuleSensorOptimizer;
 import org.sonar.scanner.sensor.ModuleSensorWrapper;
 
@@ -46,20 +48,22 @@ import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-public class ModuleSensorExtensionDictionnaryTest {
-  private ModuleSensorOptimizer sensorOptimizer = mock(ModuleSensorOptimizer.class);
+public class ModuleSensorExtensionDictionaryTest {
+  private final ModuleSensorOptimizer sensorOptimizer = mock(ModuleSensorOptimizer.class);
+  private final MutableFileSystem fileSystem = mock(MutableFileSystem.class);
+  private final BranchConfiguration branchConfiguration = mock(BranchConfiguration.class);
 
   @Before
   public void setUp() {
     when(sensorOptimizer.shouldExecute(any(DefaultSensorDescriptor.class))).thenReturn(true);
   }
 
-  private ModuleSensorExtensionDictionnary newSelector(Object... extensions) {
+  private ModuleSensorExtensionDictionary newSelector(Object... extensions) {
     ComponentContainer iocContainer = new ComponentContainer();
     for (Object extension : extensions) {
       iocContainer.addSingleton(extension);
     }
-    return new ModuleSensorExtensionDictionnary(iocContainer, mock(ModuleSensorContext.class), sensorOptimizer);
+    return new ModuleSensorExtensionDictionary(iocContainer, mock(ModuleSensorContext.class), sensorOptimizer, fileSystem, branchConfiguration);
   }
 
   @Test
@@ -67,7 +71,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     final Sensor sensor1 = new FakeSensor();
     final Sensor sensor2 = new FakeSensor();
 
-    ModuleSensorExtensionDictionnary selector = newSelector(sensor1, sensor2);
+    ModuleSensorExtensionDictionary selector = newSelector(sensor1, sensor2);
     Collection<Sensor> sensors = selector.select(Sensor.class, true, extension -> extension.equals(sensor1));
     assertThat(sensors).contains(sensor1);
     assertEquals(1, sensors.size());
@@ -79,7 +83,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Sensor sensor2 = new FakeSensor();
     FieldDecorated.Decorator decorator = mock(FieldDecorated.Decorator.class);
 
-    ModuleSensorExtensionDictionnary selector = newSelector(sensor1, sensor2, decorator);
+    ModuleSensorExtensionDictionary selector = newSelector(sensor1, sensor2, decorator);
     Collection<Sensor> sensors = selector.select(Sensor.class, false, null);
 
     assertThat(sensors).containsOnly(sensor1, sensor2);
@@ -100,7 +104,8 @@ public class ModuleSensorExtensionDictionnaryTest {
     ComponentContainer child = parent.createChild();
     child.addSingleton(c);
 
-    ModuleSensorExtensionDictionnary dictionnary = new ModuleSensorExtensionDictionnary(child, mock(ModuleSensorContext.class), mock(ModuleSensorOptimizer.class));
+    ModuleSensorExtensionDictionary dictionnary = new ModuleSensorExtensionDictionary(child, mock(ModuleSensorContext.class), mock(ModuleSensorOptimizer.class),
+      fileSystem, branchConfiguration);
     assertThat(dictionnary.select(Sensor.class, true, null)).containsOnly(a, b, c);
   }
 
@@ -110,7 +115,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Object b = new MethodDependentOf(a);
     Object c = new MethodDependentOf(b);
 
-    ModuleSensorExtensionDictionnary selector = newSelector(b, c, a);
+    ModuleSensorExtensionDictionary selector = newSelector(b, c, a);
     List<Object> extensions = Lists.newArrayList(selector.select(Marker.class, true, null));
 
     assertThat(extensions).hasSize(3);
@@ -124,7 +129,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Object a = new GeneratesSomething("foo");
     Object b = new MethodDependentOf("foo");
 
-    ModuleSensorExtensionDictionnary selector = newSelector(a, b);
+    ModuleSensorExtensionDictionary selector = newSelector(a, b);
     List<Object> extensions = Lists.newArrayList(selector.select(Marker.class, true, null));
 
     assertThat(extensions.size()).isEqualTo(2);
@@ -145,7 +150,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Object a = new GeneratesSomething("foo");
     Object b = new MethodDependentOf(Arrays.asList("foo"));
 
-    ModuleSensorExtensionDictionnary selector = newSelector(a, b);
+    ModuleSensorExtensionDictionary selector = newSelector(a, b);
     List<Object> extensions = Lists.newArrayList(selector.select(Marker.class, true, null));
 
     assertThat(extensions).hasSize(2);
@@ -166,7 +171,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Object a = new GeneratesSomething("foo");
     Object b = new MethodDependentOf(new String[] {"foo"});
 
-    ModuleSensorExtensionDictionnary selector = newSelector(a, b);
+    ModuleSensorExtensionDictionary selector = newSelector(a, b);
     List<Object> extensions = Lists.newArrayList(selector.select(Marker.class, true, null));
 
     assertThat(extensions).hasSize(2);
@@ -187,7 +192,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Object a = new ClassDependedUpon();
     Object b = new ClassDependsUpon();
 
-    ModuleSensorExtensionDictionnary selector = newSelector(a, b);
+    ModuleSensorExtensionDictionary selector = newSelector(a, b);
     List<Object> extensions = Lists.newArrayList(selector.select(Marker.class, true, null));
 
     assertThat(extensions).hasSize(2);
@@ -210,7 +215,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Object b = new InterfaceDependsUpon() {
     };
 
-    ModuleSensorExtensionDictionnary selector = newSelector(a, b);
+    ModuleSensorExtensionDictionary selector = newSelector(a, b);
     List<Object> extensions = Lists.newArrayList(selector.select(Marker.class, true, null));
 
     assertThat(extensions).hasSize(2);
@@ -231,7 +236,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     Object a = new SubClass("foo");
     Object b = new MethodDependentOf("foo");
 
-    ModuleSensorExtensionDictionnary selector = newSelector(b, a);
+    ModuleSensorExtensionDictionary selector = newSelector(b, a);
     List<Object> extensions = Lists.newArrayList(selector.select(Marker.class, true, null));
 
     assertThat(extensions).hasSize(2);
@@ -249,7 +254,7 @@ public class ModuleSensorExtensionDictionnaryTest {
 
   @Test(expected = IllegalStateException.class)
   public void annotatedMethodsCanNotBePrivate() {
-    ModuleSensorExtensionDictionnary selector = newSelector();
+    ModuleSensorExtensionDictionary selector = newSelector();
     Object wrong = new Object() {
       @DependsUpon
       private Object foo() {
@@ -265,7 +270,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     NormalSensor normal = new NormalSensor();
     PostSensor post = new PostSensor();
 
-    ModuleSensorExtensionDictionnary selector = newSelector(normal, post, pre);
+    ModuleSensorExtensionDictionary selector = newSelector(normal, post, pre);
     assertThat(selector.selectSensors(false)).extracting("wrappedSensor").containsExactly(pre, normal, post);
   }
 
@@ -275,7 +280,7 @@ public class ModuleSensorExtensionDictionnaryTest {
     NormalSensor normal = new NormalSensor();
     PostSensorSubclass post = new PostSensorSubclass();
 
-    ModuleSensorExtensionDictionnary selector = newSelector(normal, post, pre);
+    ModuleSensorExtensionDictionary selector = newSelector(normal, post, pre);
     List extensions = Lists.newArrayList(selector.select(Sensor.class, true, null));
 
     assertThat(extensions).containsExactly(pre, normal, post);
@@ -285,7 +290,7 @@ public class ModuleSensorExtensionDictionnaryTest {
   public void selectSensors() {
     FakeSensor nonGlobalSensor = new FakeSensor();
     FakeGlobalSensor globalSensor = new FakeGlobalSensor();
-    ModuleSensorExtensionDictionnary selector = newSelector(nonGlobalSensor, globalSensor);
+    ModuleSensorExtensionDictionary selector = newSelector(nonGlobalSensor, globalSensor);
 
     // verify non-global sensor
     Collection<ModuleSensorWrapper> extensions = selector.selectSensors(false);
diff --git a/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionnaryTest.java b/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionaryTest.java
index bfc29675ffa..3a016aa2acc 100644
--- a/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionnaryTest.java
+++ b/sonar-scanner-engine/src/test/java/org/sonar/scanner/bootstrap/PostJobExtensionDictionaryTest.java
@@ -37,7 +37,7 @@ import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-public class PostJobExtensionDictionnaryTest {
+public class PostJobExtensionDictionaryTest {
   private PostJobOptimizer postJobOptimizer = mock(PostJobOptimizer.class);
 
   @Before
@@ -45,12 +45,12 @@ public class PostJobExtensionDictionnaryTest {
     when(postJobOptimizer.shouldExecute(any(DefaultPostJobDescriptor.class))).thenReturn(true);
   }
 
-  private PostJobExtensionDictionnary newSelector(Object... extensions) {
+  private PostJobExtensionDictionary newSelector(Object... extensions) {
     ComponentContainer iocContainer = new ComponentContainer();
     for (Object extension : extensions) {
       iocContainer.addSingleton(extension);
     }
-    return new PostJobExtensionDictionnary(iocContainer, postJobOptimizer, mock(PostJobContext.class));
+    return new PostJobExtensionDictionary(iocContainer, postJobOptimizer, mock(PostJobContext.class));
   }
 
   @Test
@@ -58,7 +58,7 @@ public class PostJobExtensionDictionnaryTest {
     PrePostJob pre = new PrePostJob();
     NormalPostJob normal = new NormalPostJob();
 
-    PostJobExtensionDictionnary selector = newSelector(normal, pre);
+    PostJobExtensionDictionary selector = newSelector(normal, pre);
     assertThat(selector.selectPostJobs()).extracting("wrappedPostJob").containsExactly(pre, normal);
   }
 
diff --git a/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/ModuleSensorsExecutorTest.java b/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/ModuleSensorsExecutorTest.java
index 2b0095d23bf..820a528c040 100644
--- a/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/ModuleSensorsExecutorTest.java
+++ b/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/ModuleSensorsExecutorTest.java
@@ -19,41 +19,65 @@
  */
 package org.sonar.scanner.phases;
 
+import com.tngtech.java.junit.dataprovider.DataProvider;
+import com.tngtech.java.junit.dataprovider.DataProviderRunner;
+import com.tngtech.java.junit.dataprovider.UseDataProvider;
 import java.io.IOException;
 import java.util.Collections;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
 import org.sonar.api.batch.bootstrap.ProjectDefinition;
+import org.sonar.api.batch.fs.internal.DefaultInputModule;
 import org.sonar.api.batch.fs.internal.SensorStrategy;
+import org.sonar.api.batch.fs.internal.TestInputFileBuilder;
 import org.sonar.api.batch.sensor.Sensor;
+import org.sonar.api.batch.sensor.SensorContext;
+import org.sonar.api.batch.sensor.SensorDescriptor;
+import org.sonar.api.batch.sensor.internal.DefaultSensorDescriptor;
+import org.sonar.api.utils.log.LogTester;
 import org.sonar.scanner.bootstrap.ScannerPluginRepository;
-import org.sonar.api.batch.fs.internal.DefaultInputModule;
 import org.sonar.scanner.fs.InputModuleHierarchy;
-import org.sonar.api.batch.fs.internal.TestInputFileBuilder;
-import org.sonar.scanner.sensor.ModuleSensorExtensionDictionnary;
+import org.sonar.scanner.scan.branch.BranchConfiguration;
+import org.sonar.scanner.scan.branch.BranchType;
+import org.sonar.scanner.scan.filesystem.MutableFileSystem;
+import org.sonar.scanner.sensor.ModuleSensorContext;
+import org.sonar.scanner.sensor.ModuleSensorExtensionDictionary;
+import org.sonar.scanner.sensor.ModuleSensorOptimizer;
 import org.sonar.scanner.sensor.ModuleSensorWrapper;
 import org.sonar.scanner.sensor.ModuleSensorsExecutor;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.verifyZeroInteractions;
 import static org.mockito.Mockito.when;
 
+@RunWith(DataProviderRunner.class)
 public class ModuleSensorsExecutorTest {
   @Rule
   public TemporaryFolder temp = new TemporaryFolder();
 
+  @Rule
+  public LogTester logTester = new LogTester();
+
   private ModuleSensorsExecutor rootModuleExecutor;
   private ModuleSensorsExecutor subModuleExecutor;
 
-  private SensorStrategy strategy = new SensorStrategy();
+  private final SensorStrategy strategy = new SensorStrategy();
 
-  private ModuleSensorWrapper perModuleSensor = mock(ModuleSensorWrapper.class);
-  private ModuleSensorWrapper globalSensor = mock(ModuleSensorWrapper.class);
-  private ScannerPluginRepository pluginRepository = mock(ScannerPluginRepository.class);
+  private final ModuleSensorWrapper perModuleSensor = mock(ModuleSensorWrapper.class);
+  private final ModuleSensorWrapper globalSensor = mock(ModuleSensorWrapper.class);
+  private final ScannerPluginRepository pluginRepository = mock(ScannerPluginRepository.class);
+  private final ModuleSensorContext context = mock(ModuleSensorContext.class);
+  private final ModuleSensorOptimizer optimizer = mock(ModuleSensorOptimizer.class);
+  private final ScannerPluginRepository pluginRepo = mock(ScannerPluginRepository.class);
+  private final MutableFileSystem fileSystem = mock(MutableFileSystem.class);
+  private final BranchConfiguration branchConfiguration = mock(BranchConfiguration.class);
 
   @Before
   public void setUp() throws IOException {
@@ -65,7 +89,7 @@ public class ModuleSensorsExecutorTest {
     when(globalSensor.shouldExecute()).thenReturn(true);
     when(globalSensor.wrappedSensor()).thenReturn(mock(Sensor.class));
 
-    ModuleSensorExtensionDictionnary selector = mock(ModuleSensorExtensionDictionnary.class);
+    ModuleSensorExtensionDictionary selector = mock(ModuleSensorExtensionDictionary.class);
     when(selector.selectSensors(false)).thenReturn(Collections.singleton(perModuleSensor));
     when(selector.selectSensors(true)).thenReturn(Collections.singleton(globalSensor));
 
@@ -105,4 +129,91 @@ public class ModuleSensorsExecutorTest {
 
     verifyNoMoreInteractions(perModuleSensor, globalSensor);
   }
+
+  @Test
+  @UseDataProvider("sensorsOnlyChangedInPR")
+  public void should_restrict_filesystem_when_pull_request_and_expected_sensor(String sensorName) throws IOException {
+    when(branchConfiguration.branchType()).thenReturn(BranchType.PULL_REQUEST);
+    ModuleSensorsExecutor executor = createModuleExecutor(sensorName);
+
+    executor.execute();
+
+    verify(fileSystem, times(2)).setRestrictToChangedFiles(true);
+
+    assertThat(logTester.logs().stream().anyMatch(
+      p -> p.contains(String.format("Sensor %s is restricted to changed files only", sensorName)))
+    ).isTrue();
+  }
+
+  @Test
+  @UseDataProvider("sensorsOnlyChangedInPR")
+  public void should_not_restrict_filesystem_when_branch(String sensorName) throws IOException {
+    when(branchConfiguration.branchType()).thenReturn(BranchType.BRANCH);
+    ModuleSensorsExecutor executor = createModuleExecutor(sensorName);
+
+    executor.execute();
+
+    verify(fileSystem, times(2)).setRestrictToChangedFiles(false);
+
+    assertThat(logTester.logs().stream().anyMatch(
+      p -> p.contains(String.format("Sensor %s is restricted to changed files only", sensorName)))
+    ).isFalse();
+  }
+
+  @Test
+  public void should_not_restrict_filesystem_when_pull_request_and_non_expected_sensor() throws IOException {
+    String sensorName = "NonRestrictedSensor";
+    when(branchConfiguration.branchType()).thenReturn(BranchType.PULL_REQUEST);
+    ModuleSensorsExecutor executor = createModuleExecutor(sensorName);
+
+    executor.execute();
+
+    verify(fileSystem, times(2)).setRestrictToChangedFiles(false);
+
+    assertThat(logTester.logs().stream().anyMatch(
+      p -> p.contains(String.format("Sensor %s is restricted to changed files only", sensorName)))
+    ).isFalse();
+  }
+
+  @DataProvider
+  public static Object[][] sensorsOnlyChangedInPR() {
+    return new Object[][] {DefaultSensorDescriptor.SENSORS_ONLY_CHANGED_IN_PR.toArray()};
+  }
+
+  private ModuleSensorsExecutor createModuleExecutor(String sensorName) throws IOException {
+    Sensor sensor = new TestSensor(sensorName);
+    ModuleSensorWrapper sensorWrapper = new ModuleSensorWrapper(sensor, context, optimizer, fileSystem, branchConfiguration);
+
+    ModuleSensorExtensionDictionary selector = mock(ModuleSensorExtensionDictionary.class);
+    when(selector.selectSensors(false)).thenReturn(Collections.singleton(sensorWrapper));
+    when(selector.selectSensors(true)).thenReturn(Collections.singleton(sensorWrapper));
+
+    ProjectDefinition rootDef = ProjectDefinition.create().setKey("root").setBaseDir(temp.newFolder()).setWorkDir(temp.newFolder());
+
+    DefaultInputModule rootModule = TestInputFileBuilder.newDefaultInputModule(rootDef);
+
+    InputModuleHierarchy hierarchy = mock(InputModuleHierarchy.class);
+    when(hierarchy.isRoot(rootModule)).thenReturn(true);
+
+    return new ModuleSensorsExecutor(selector, rootModule, hierarchy, strategy, pluginRepo);
+  }
+
+  private static class TestSensor implements Sensor {
+
+    private final String name;
+
+    public TestSensor(String name) {
+      this.name = name;
+    }
+
+    @Override
+    public void describe(SensorDescriptor descriptor) {
+      descriptor.name(name);
+    }
+
+    @Override
+    public void execute(SensorContext context) {
+
+    }
+  }
 }
diff --git a/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/PostJobsExecutorTest.java b/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/PostJobsExecutorTest.java
index a4888b77686..318b42f6b15 100644
--- a/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/PostJobsExecutorTest.java
+++ b/sonar-scanner-engine/src/test/java/org/sonar/scanner/phases/PostJobsExecutorTest.java
@@ -22,7 +22,7 @@ package org.sonar.scanner.phases;
 import java.util.Arrays;
 import org.junit.Before;
 import org.junit.Test;
-import org.sonar.scanner.bootstrap.PostJobExtensionDictionnary;
+import org.sonar.scanner.bootstrap.PostJobExtensionDictionary;
 import org.sonar.scanner.postjob.PostJobWrapper;
 import org.sonar.scanner.postjob.PostJobsExecutor;
 
@@ -34,7 +34,7 @@ import static org.mockito.Mockito.when;
 public class PostJobsExecutorTest {
   private PostJobsExecutor executor;
 
-  private PostJobExtensionDictionnary selector = mock(PostJobExtensionDictionnary.class);
+  private PostJobExtensionDictionary selector = mock(PostJobExtensionDictionary.class);
   private PostJobWrapper job1 = mock(PostJobWrapper.class);
   private PostJobWrapper job2 = mock(PostJobWrapper.class);
 
diff --git a/sonar-scanner-engine/src/test/java/org/sonar/scanner/scan/filesystem/MutableFileSystemTest.java b/sonar-scanner-engine/src/test/java/org/sonar/scanner/scan/filesystem/MutableFileSystemTest.java
new file mode 100644
index 00000000000..f55a46f65ae
--- /dev/null
+++ b/sonar-scanner-engine/src/test/java/org/sonar/scanner/scan/filesystem/MutableFileSystemTest.java
@@ -0,0 +1,85 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2021 SonarSource SA
+ * mailto:info AT sonarsource DOT com
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.scanner.scan.filesystem;
+
+import java.util.Locale;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.sonar.api.batch.fs.InputFile;
+import org.sonar.api.batch.fs.internal.TestInputFileBuilder;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class MutableFileSystemTest {
+
+  private static final String LANGUAGE = "php";
+
+  @Rule
+  public TemporaryFolder temp = new TemporaryFolder();
+
+  private MutableFileSystem underTest;
+
+  @Before
+  public void prepare() throws Exception {
+    underTest = new MutableFileSystem(temp.newFolder().toPath());
+  }
+
+  @Test
+  public void return_all_files_when_not_restricted() {
+    assertThat(underTest.inputFiles(underTest.predicates().all())).isEmpty();
+    addFileWithAllStatus();
+    underTest.setRestrictToChangedFiles(false);
+
+    assertThat(underTest.inputFiles(underTest.predicates().all())).hasSize(3);
+    assertThat(underTest.inputFile(underTest.predicates().hasFilename(generateFilename(InputFile.Status.ADDED)))).isNotNull();
+    assertThat(underTest.inputFile(underTest.predicates().hasFilename(generateFilename(InputFile.Status.SAME)))).isNotNull();
+    assertThat(underTest.inputFile(underTest.predicates().hasFilename(generateFilename(InputFile.Status.CHANGED)))).isNotNull();
+  }
+
+  @Test
+  public void return_only_changed_files_when_restricted() {
+    assertThat(underTest.inputFiles(underTest.predicates().all())).isEmpty();
+    addFileWithAllStatus();
+    underTest.setRestrictToChangedFiles(true);
+
+    assertThat(underTest.inputFiles(underTest.predicates().all())).hasSize(2);
+    assertThat(underTest.inputFile(underTest.predicates().hasFilename(generateFilename(InputFile.Status.ADDED)))).isNotNull();
+    assertThat(underTest.inputFile(underTest.predicates().hasFilename(generateFilename(InputFile.Status.SAME)))).isNull();
+    assertThat(underTest.inputFile(underTest.predicates().hasFilename(generateFilename(InputFile.Status.CHANGED)))).isNotNull();
+  }
+
+  private void addFileWithAllStatus() {
+    addFile(InputFile.Status.ADDED);
+    addFile(InputFile.Status.CHANGED);
+    addFile(InputFile.Status.SAME);
+  }
+
+  private void addFile(InputFile.Status status) {
+    underTest.add(new TestInputFileBuilder("foo", String.format("src/%s", generateFilename(status)))
+      .setLanguage(LANGUAGE).setStatus(status).build());
+  }
+
+  private String generateFilename(InputFile.Status status) {
+    return String.format("%s.%s", status.name().toLowerCase(Locale.ROOT), LANGUAGE);
+  }
+
+}