Fix merge of branch-6.0

13 files changed, 285 insertions, 290 deletions

diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/Plugin.java b/sonar-plugin-api/src/main/java/org/sonar/api/Plugin.java
index 8fb50a0b14c..965a1b13b01 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/Plugin.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/Plugin.java
@@ -33,14 +33,13 @@ import static java.util.Objects.requireNonNull;
  * This property is automatically set by sonar-packaging-maven-plugin when building plugin.
  * <p>Example of implementation
  * <pre>
- * package com.mycompany.sonarqube;
- * public class MyPlugin implements Plugin {
+  * public class MyPlugin implements Plugin {
  *  {@literal @}Override
  *   public void define(Context context) {
  *     context.addExtensions(MySensor.class, MyRules.class);
- *     if (context.getSonarQubeVersion().isGreaterThanOrEqual(SonarQubeVersion.V5_6)) {
- *       // Extension which supports only versions 5.6 and greater
- *       // See org.sonar.api.SonarQubeVersion for more details.
+ *     if (context.getRuntime().getApiVersion().isGreaterThanOrEqual(Version.create(6, 0))) {
+ *       // Extension which supports only versions 6.0 and greater
+ *       // See org.sonar.api.SonarRuntime for more details.
  *       context.addExtension(MyNewExtension.class);
  *     }
  *   }
@@ -73,8 +72,9 @@ import static java.util.Objects.requireNonNull;
  * MyPlugin underTest = new MyPlugin();
  *
  *{@literal @}Test
- * public void test_plugin_extensions_compatible_with_5_5() {
- *   Plugin.Context context = new Plugin.Context(SonarQubeVersion.V5_5);
+ * public void test_plugin_extensions_compatible_with_5_6() {
+ *   SonarRuntime runtime = SonarRuntimeImpl.forSonarQube(Version.create(5, 6));
+ *   Plugin.Context context = new Plugin.Context(runtime);
  *   underTest.define(context);
  *   assertThat(context.getExtensions()).hasSize(4);
  * }
@@ -93,7 +93,7 @@ public interface Plugin {
     }
 
     /**
-     * @deprecated since 6.0 use {@link #getRuntimeApiVersion()}
+     * @deprecated replaced by {@link #getRuntime()}.getApiVersion() in 6.0
      */
     @Deprecated
     public Version getSonarQubeVersion() {
@@ -101,11 +101,11 @@ public interface Plugin {
     }
 
     /**
-     * Runtime API version. Can be use to conditionnaly add some extensions.
+     * Runtime environment. Can be use to add some extensions only on some conditions.
      * @since 6.0
      */
-    public Version getRuntimeApiVersion() {
-      return sonarRuntime.getApiVersion();
+    public SonarRuntime getRuntime() {
+      return sonarRuntime;
     }
 
     /**
@@ -151,13 +151,6 @@ public interface Plugin {
       return extensions;
     }
 
-    /**
-     * Test the product the plugin is currently executed in. This can allow to implement a different behavior.
-     * @since 6.0
-     */
-    public SonarProduct getRuntimeProduct() {
-      return sonarRuntime.getProduct();
-    }
   }
 
   /**
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeSide.java b/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeSide.java
index 5e02c2eae61..7aa312e76a1 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeSide.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeSide.java
@@ -20,13 +20,14 @@
 package org.sonar.api;
 
 /**
- * Differentiate runtime context in SonarQube product.
+ * Runtime stack in SonarQube product.
+ * @see SonarRuntime#getSonarQubeSide()
  * @since 6.0
  */
 public enum SonarQubeSide {
 
   SCANNER,
   SERVER,
-  COMPUTE_ENGINE;
+  COMPUTE_ENGINE
 
 }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeVersion.java b/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeVersion.java
index 044df52a450..6b4e100939f 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeVersion.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/SonarQubeVersion.java
@@ -19,118 +19,48 @@
  */
 package org.sonar.api;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import org.sonar.api.batch.ScannerSide;
-import org.sonar.api.batch.sensor.Sensor;
 import org.sonar.api.ce.ComputeEngineSide;
 import org.sonar.api.server.ServerSide;
 import org.sonar.api.utils.Version;
 
+import static java.util.Objects.requireNonNull;
+
 /**
- * Version of SonarQube at runtime. This component can be injected as a dependency
- * of plugin extensions. The main usage for a plugin is to benefit from new APIs
- * while keeping backward-compatibility with previous versions of SonarQube.
- * <br><br>
- * 
- * Example 1: a {@link Sensor} wants to use an API introduced in version 5.5 and still requires to support older versions
- * at runtime.
- * <pre>
- * public class MySensor implements Sensor {
- *
- *   public void execute(SensorContext context) {
- *     if (context.getSonarQubeVersion().isGreaterThanOrEqual(SonarQubeVersion.V5_5)) {
- *       context.newMethodIntroducedIn5_5();
- *     }
- *   }
- * }
- * </pre>
- *
- * Example 2: a plugin needs to use an API introduced in version 5.6 ({@code AnApi} in the following
- * snippet) and still requires to support version 5.5 at runtime.
- * <br>
- * <pre>
- * // Component provided by sonar-plugin-api
- * // @since 5.5
- * public interface AnApi {
- *   // implicitly since 5.5
- *   public void foo();
- *
- *   // @since 5.6
- *   public void bar();
- * }
- * 
- * // Component provided by plugin
- * public class MyExtension {
- *   private final SonarQubeVersion sonarQubeVersion;
- *   private final AnApi api;
- *
- *   public MyExtension(SonarQubeVersion sonarQubeVersion, AnApi api) {
- *     this.sonarQubeVersion = sonarQubeVersion;
- *     this.api = api;
- *   }
- *
- *   public void doSomething() {
- *     // assume that runtime is 5.5+
- *     api.foo();
- *
- *     if (sonarQubeVersion.isGreaterThanOrEqual(SonarQubeVersion.V5_6)) {
- *       api.bar();
- *     }
- *   }
- * }
- * </pre>
- * <p>
- * The minimal supported version of SonarQube is verified at runtime. As plugin is built
- * with sonar-plugin-api 5.6, we assume that the plugin requires v5.6 or greater at runtime.
- * For this reason the plugin must default which is the minimal supported version
- * in the configuration of sonar-packaging-maven-plugin 1.16+:
- * <p>
- * <pre>
- * &lt;packaging&gt;sonar-plugin&lt;/packaging&gt;
- *
- * &lt;dependencies&gt;
- *   &lt;dependency&gt;
- *     &lt;groupId&gt;org.sonarsource.sonarqube&lt;/groupId&gt;
- *     &lt;artifactId&gt;sonar-plugin-api&lt;/artifactId&gt;
- *     &lt;version&gt;5.6&lt;/version&gt;
- *     &lt;scope&gt;provided&lt;/scope&gt;
- *   &lt;/dependency&gt;
- * &lt;/dependencies&gt;
- *
- * &lt;build&gt;
- *  &lt;plugins&gt;
- *    &lt;plugin&gt;
- *      &lt;groupId&gt;org.sonarsource.sonar-packaging-maven-plugin&lt;/groupId&gt;
- *      &lt;artifactId&gt;sonar-packaging-maven-plugin&lt;/artifactId&gt;
- *      &lt;version&gt;1.16&lt;/version&gt;
- *      &lt;extensions&gt;true&lt;/extensions&gt;
- *      &lt;configuration&gt;
- *        &lt;!-- Override the default value 5.6 which is guessed from sonar-plugin-api dependency --&gt;
- *        &lt;sonarQubeMinVersion&gt;5.5&lt;/sonarQubeMinVersion&gt;
- *      &lt;/configuration&gt;
- *    &lt;/plugin&gt;
- *  &lt;/plugins&gt;
- * &lt;/build&gt;
- * </pre>
- *
+ * Version of SonarQube at runtime. Replaced by {@link SonarRuntime#getApiVersion()}.
  *
  * @since 5.5
- * @deprecated since 6.0 replaced by {@link SonarRuntime}
+ * @deprecated replaced by {@link SonarRuntime} in version 6.0
  */
 @ScannerSide
 @ServerSide
 @ComputeEngineSide
 @Immutable
 @Deprecated
-public class SonarQubeVersion extends SonarRuntime {
+public class SonarQubeVersion {
+  /**
+   * Constant for version 5.5
+   */
+  public static final Version V5_5 = Version.create(5, 5);
 
-  public SonarQubeVersion(Version version, SonarProduct product, @Nullable SonarQubeSide sonarQubeSide) {
-    super(version, product, sonarQubeSide);
+  /**
+   * Constant for version 5.6
+   */
+  public static final Version V5_6 = Version.create(5, 6);
+
+  private final Version version;
+
+  public SonarQubeVersion(Version version) {
+    requireNonNull(version);
+    this.version = version;
   }
 
   public Version get() {
-    return super.getApiVersion();
+    return this.version;
   }
 
+  public boolean isGreaterThanOrEqual(Version than) {
+    return this.version.isGreaterThanOrEqual(than);
+  }
 }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/SonarRuntime.java b/sonar-plugin-api/src/main/java/org/sonar/api/SonarRuntime.java
index 86b37e9e54c..b2663ca1da8 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/SonarRuntime.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/SonarRuntime.java
@@ -19,75 +19,81 @@
  */
 package org.sonar.api;
 
-import com.google.common.base.Preconditions;
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.Immutable;
 import org.sonar.api.batch.ScannerSide;
 import org.sonar.api.batch.sensor.Sensor;
+import org.sonar.api.batch.sensor.SensorContext;
 import org.sonar.api.ce.ComputeEngineSide;
 import org.sonar.api.server.ServerSide;
 import org.sonar.api.utils.Version;
 import org.sonarsource.api.sonarlint.SonarLintSide;
 
-import static java.util.Objects.requireNonNull;
-
 /**
- * Version of SonarQube at runtime. This component can be injected as a dependency
- * of plugin extensions. The main usage for a plugin is to benefit from new APIs
- * while keeping backward-compatibility with previous versions of SonarQube.
- * <br><br>
- * 
- * Example 1: a {@link Sensor} wants to use an API introduced in version 5.5 and still requires to support older versions
- * at runtime.
- * <pre>
- * public class MySensor implements Sensor {
+ * Information about runtime environment.
  *
- *   public void execute(SensorContext context) {
- *     if (context.getRuntimeApiVersion().isGreaterThanOrEqual(RuntimeApiVersion.V5_5)) {
- *       context.newMethodIntroducedIn5_5();
- *     }
- *   }
- * }
- * </pre>
+ * <p>
+ * A usage for plugins is to benefit from new APIs
+ * while keeping backward-compatibility with previous versions of SonarQube
+ * or SonarLint.
+ * </p>
  *
- * Example 2: a plugin needs to use an API introduced in version 5.6 ({@code AnApi} in the following
- * snippet) and still requires to support version 5.5 at runtime.
- * <br>
+ * <p>
+ * Example: a plugin extension wants to use a new feature of API 6.0 without
+ * breaking compatibility with version 5.6 at runtime. This new feature
+ * would be enabled only in 6.0 and greater runtimes.
+ * </p>
  * <pre>
  * // Component provided by sonar-plugin-api
- * // @since 5.5
+ * // @since 5.6
  * public interface AnApi {
- *   // implicitly since 5.5
+ *   // implicitly since 5.6
  *   public void foo();
  *
- *   // @since 5.6
+ *   // @since 6.0
  *   public void bar();
  * }
  * 
- * // Component provided by plugin
+ * // Plugin extension
  * public class MyExtension {
- *   private final RuntimeApiVersion runtimeApiVersion;
+ *   private final SonarRuntime sonarRuntime;
  *   private final AnApi api;
  *
- *   public MyExtension(RuntimeApiVersion runtimeApiVersion, AnApi api) {
- *     this.runtimeApiVersion = runtimeApiVersion;
+ *   public MyExtension(SonarRuntime sonarRuntime, AnApi api) {
+ *     this.sonarRuntime = sonarRuntime;
  *     this.api = api;
  *   }
  *
  *   public void doSomething() {
- *     // assume that runtime is 5.5+
+ *     // assume that minimal supported runtime is 5.6
  *     api.foo();
  *
- *     if (runtimeApiVersion.isGreaterThanOrEqual(SonarQubeVersion.V5_6)) {
+ *     if (sonarRuntime.getApiVersion().isGreaterThanOrEqual(Version.create(6, 0))) {
  *       api.bar();
  *     }
  *   }
  * }
  * </pre>
+ *
+ *
+ * <p>
+ *   Note that {@link Sensor} extensions can directly get {@link SonarRuntime} through
+ * {@link SensorContext#runtime()}, without using constructor injection:
+ * </p>
+ * <pre>
+ * public class MySensor implements Sensor {
+ *
+ *   public void execute(SensorContext context) {
+ *     if (context.runtime().getApiVersion().isGreaterThanOrEqual(Version.create(6, 0)) {
+ *       context.newMethodIntroducedIn6_0();
+ *     }
+ *   }
+ *
+ * }
+ * </pre>
+ *
  * <p>
  * The minimal supported version of plugin API is verified at runtime. As plugin is built
- * with sonar-plugin-api 5.6, we assume that the plugin requires v5.6 or greater at runtime.
- * For this reason the plugin must default which is the minimal supported version
+ * with sonar-plugin-api 6.0, we assume that the plugin requires v6.0 or greater at runtime.
+ * For this reason the plugin must override the minimal supported version
  * in the configuration of sonar-packaging-maven-plugin 1.16+:
  * <p>
  * <pre>
@@ -97,7 +103,7 @@ import static java.util.Objects.requireNonNull;
  *   &lt;dependency&gt;
  *     &lt;groupId&gt;org.sonarsource.sonarqube&lt;/groupId&gt;
  *     &lt;artifactId&gt;sonar-plugin-api&lt;/artifactId&gt;
- *     &lt;version&gt;5.6&lt;/version&gt;
+ *     &lt;version&gt;6.0&lt;/version&gt;
  *     &lt;scope&gt;provided&lt;/scope&gt;
  *   &lt;/dependency&gt;
  * &lt;/dependencies&gt;
@@ -111,80 +117,42 @@ import static java.util.Objects.requireNonNull;
  *      &lt;extensions&gt;true&lt;/extensions&gt;
  *      &lt;configuration&gt;
  *        &lt;!-- Override the default value 5.6 which is guessed from sonar-plugin-api dependency --&gt;
- *        &lt;sonarQubeMinVersion&gt;5.5&lt;/sonarQubeMinVersion&gt;
+ *        &lt;sonarQubeMinVersion&gt;5.6&lt;/sonarQubeMinVersion&gt;
  *      &lt;/configuration&gt;
  *    &lt;/plugin&gt;
  *  &lt;/plugins&gt;
  * &lt;/build&gt;
  * </pre>
  *
- *
+ * <p>
+ * Unit tests of plugin extensions can create instances of {@link SonarRuntime}
+ * via {@link org.sonar.api.internal.SonarRuntimeImpl}.
+ * </p>
  * @since 6.0
  */
 @ScannerSide
 @ServerSide
 @ComputeEngineSide
 @SonarLintSide
-@Immutable
-public class SonarRuntime {
+public interface SonarRuntime {
 
   /**
-   * Constant for version 5.5
-   */
-  public static final Version V5_5 = Version.create(5, 5);
-
-  /**
-   * Constant for version 5.6
-   */
-  public static final Version V5_6 = Version.create(5, 6);
-
-  /**
-   * Constant for version 6.0
-   */
-  public static final Version V6_0 = Version.create(6, 0);
-
-  private final Version version;
-  private final SonarProduct product;
-  private final SonarQubeSide sonarQubeSide;
-
-  public SonarRuntime(Version version, SonarProduct product, @Nullable SonarQubeSide sonarQubeSide) {
-    requireNonNull(version);
-    requireNonNull(product);
-    Preconditions.checkArgument((product == SonarProduct.SONARQUBE) == (sonarQubeSide != null), "sonarQubeSide should be provided only for SonarQube product");
-    this.version = version;
-    this.product = product;
-    this.sonarQubeSide = sonarQubeSide;
-  }
-
-  /**
-   * Runtime version of sonar-plugin-api. This could be used to test if a new feature can be used or not without using reflection.
-   */
-  public Version getApiVersion() {
-    return this.version;
-  }
-
-  public boolean isGreaterThanOrEqual(Version than) {
-    return this.version.isGreaterThanOrEqual(than);
-  }
+  * Version of API (sonar-plugin-api artifact) at runtime.
+  * It can be helpful to call some API classes/methods without checking their availability at
+  * runtime by using reflection.
+  */
+  Version getApiVersion();
 
   /**
-   * Allow to know what is current runtime product. Can be used to implement different behavior depending on runtime (SonarQube, SonarLint, ...).
-   * @since 6.0
+   * The product being executed at runtime. It targets analysers so that they can implement
+   * different behaviours in SonarQube and SonarLint.
    */
-  public SonarProduct getProduct() {
-    return product;
-  }
+  SonarProduct getProduct();
 
   /**
-   * Allow to know the precise runtime context in SonarQube product. Only valid when {@link #getProduct()} returns {@link SonarProduct#SONARQUBE}
-   * @since 6.0
-   * @throws UnsupportedOperationException if called and {@link #getProduct()} is not equal to {@link SonarProduct#SONARQUBE}
+   * The SonarQube stack being executed at runtime.
+   * @throws UnsupportedOperationException if {@link #getProduct()} is not equal to {@link SonarProduct#SONARQUBE}
    */
-  public SonarQubeSide getSonarQubeSide() {
-    if (sonarQubeSide == null) {
-      throw new UnsupportedOperationException("Can only be called in SonarQube");
-    }
-    return sonarQubeSide;
-  }
+  SonarQubeSide getSonarQubeSide();
 
 }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/SensorContext.java b/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/SensorContext.java
index 9612521b23f..c92ab74a5d9 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/SensorContext.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/SensorContext.java
@@ -20,7 +20,7 @@
 package org.sonar.api.batch.sensor;
 
 import java.io.Serializable;
-import org.sonar.api.SonarProduct;
+import org.sonar.api.SonarRuntime;
 import org.sonar.api.batch.fs.FileSystem;
 import org.sonar.api.batch.fs.InputModule;
 import org.sonar.api.batch.rule.ActiveRules;
@@ -66,25 +66,24 @@ public interface SensorContext {
 
   /**
    * @since 5.5
-   * @deprecated since 6.0 replaced by {@link #getRuntimeApiVersion()}
+   * @deprecated replaced by {@link #runtime()}.getApiVersion() in version 6.0.
    */
   @Deprecated
   Version getSonarQubeVersion();
 
   /**
+   * Runtime information, mainly:
+   * <ul>
+   *   <li>to be able to have different behaviours between SonarQube and SonarLint</li>
+   *   <li>to enable new features depending on version of API available at runtime</li>
+   * </ul>
    * @since 6.0
    */
-  Version getRuntimeApiVersion();
-
-  /**
-   * Test the product the plugin is currently executed in. This can allow to implement a different behavior.
-   * @since 6.0
-   */
-  SonarProduct getRuntimeProduct();
+  SonarRuntime runtime();
 
   /**
    * Test if a cancellation of the analysis was requested. Sensors should periodically test this flag
-   * and gracefully stop if value is true. For example it could be tested between each processed file.
+   * and gracefully stop if value is {@code true}. For example it could be tested between each processed file.
    * @since 6.0
    */
   boolean isCancelled();
@@ -139,7 +138,7 @@ public interface SensorContext {
 
   /**
    * Builder to declare errors that happened while processing a source file.
-   * Don't forget to call {@link NewAnalisisError#save()}.
+   * Don't forget to call {@link NewAnalysisError#save()}.
    * @since 6.0
    */
   NewAnalysisError newAnalysisError();
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/internal/SensorContextTester.java b/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/internal/SensorContextTester.java
index a2c8cd2ac26..ba9020829a4 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/internal/SensorContextTester.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/batch/sensor/internal/SensorContextTester.java
@@ -19,7 +19,6 @@
  */
 package org.sonar.api.batch.sensor.internal;
 
-import com.google.common.annotations.Beta;
 import java.io.File;
 import java.io.Serializable;
 import java.nio.file.Path;
@@ -30,9 +29,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import javax.annotation.CheckForNull;
-import org.sonar.api.SonarProduct;
 import org.sonar.api.SonarQubeSide;
-import org.sonar.api.SonarQubeVersion;
+import org.sonar.api.SonarRuntime;
 import org.sonar.api.batch.fs.InputModule;
 import org.sonar.api.batch.fs.TextRange;
 import org.sonar.api.batch.fs.internal.DefaultFileSystem;
@@ -63,7 +61,8 @@ import org.sonar.api.batch.sensor.measure.internal.DefaultMeasure;
 import org.sonar.api.batch.sensor.symbol.NewSymbolTable;
 import org.sonar.api.batch.sensor.symbol.internal.DefaultSymbolTable;
 import org.sonar.api.config.Settings;
-import org.sonar.api.internal.SonarRuntimeFactory;
+import org.sonar.api.internal.ApiVersion;
+import org.sonar.api.internal.SonarRuntimeImpl;
 import org.sonar.api.measures.Metric;
 import org.sonar.api.utils.System2;
 import org.sonar.api.utils.Version;
@@ -84,7 +83,6 @@ import org.sonar.duplications.internal.pmd.TokensLine;
  * Then pass it to your {@link Sensor}. You can then query elements provided by your sensor using methods {@link #allIssues()}, ...
  * 
  */
-@Beta
 public class SensorContextTester implements SensorContext {
 
   private Settings settings;
@@ -92,7 +90,7 @@ public class SensorContextTester implements SensorContext {
   private ActiveRules activeRules;
   private InMemorySensorStorage sensorStorage;
   private InputModule module;
-  private SonarQubeVersion sqVersion;
+  private SonarRuntime runtime;
   private boolean cancelled;
 
   private SensorContextTester(Path moduleBaseDir) {
@@ -101,7 +99,7 @@ public class SensorContextTester implements SensorContext {
     this.activeRules = new ActiveRulesBuilder().build();
     this.sensorStorage = new InMemorySensorStorage();
     this.module = new DefaultInputModule("projectKey");
-    this.sqVersion = SonarRuntimeFactory.create(System2.INSTANCE, SonarProduct.SONARQUBE, SonarQubeSide.SCANNER);
+    this.runtime = SonarRuntimeImpl.forSonarQube(ApiVersion.load(System2.INSTANCE), SonarQubeSide.SCANNER);
   }
 
   public static SensorContextTester create(File moduleBaseDir) {
@@ -143,26 +141,25 @@ public class SensorContextTester implements SensorContext {
   }
 
   /**
-   * Default value is the version of this API. You can override it
-   * using {@link #setSonarQubeVersion(Version)} to test your Sensor behavior.
+   * Default value is the version of this API at compilation time. You can override it
+   * using {@link #setRuntime(SonarRuntime)} to test your Sensor behaviour.
    */
   @Override
   public Version getSonarQubeVersion() {
-    return sqVersion.getApiVersion();
-  }
-
-  @Override
-  public Version getRuntimeApiVersion() {
-    return sqVersion.getApiVersion();
+    return runtime().getApiVersion();
   }
 
+  /**
+   * @see #setRuntime(SonarRuntime) to override defaults (SonarQube scanner with version
+   * of this API as used at compilation time).
+   */
   @Override
-  public SonarProduct getRuntimeProduct() {
-    return sqVersion.getProduct();
+  public SonarRuntime runtime() {
+    return runtime;
   }
 
-  public SensorContextTester setRuntime(Version version, SonarProduct product, SonarQubeSide sonarQubeSide) {
-    this.sqVersion = new SonarQubeVersion(version, product, sonarQubeSide);
+  public SensorContextTester setRuntime(SonarRuntime runtime) {
+    this.runtime = runtime;
     return this;
   }
 
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/internal/SonarRuntimeFactory.java b/sonar-plugin-api/src/main/java/org/sonar/api/internal/ApiVersion.java
index b47189b58a8..de57cf0761a 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/internal/SonarRuntimeFactory.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/internal/ApiVersion.java
@@ -23,29 +23,27 @@ import com.google.common.io.Resources;
 import java.io.IOException;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
-import javax.annotation.Nullable;
-import org.sonar.api.SonarProduct;
-import org.sonar.api.SonarQubeSide;
-import org.sonar.api.SonarQubeVersion;
 import org.sonar.api.utils.System2;
 import org.sonar.api.utils.Version;
 
 /**
- * For internal use only.
+ * For internal use
+ *
+ * @since 6.0
  */
-public class SonarRuntimeFactory {
+public class ApiVersion {
 
   private static final String FILE_PATH = "/sq-version.txt";
 
-  private SonarRuntimeFactory() {
-    // prevents instantiation
+  private ApiVersion() {
+    // only static methods
   }
 
-  public static SonarQubeVersion create(System2 system, SonarProduct product, @Nullable SonarQubeSide sonarQubeSide) {
+  public static Version load(System2 system) {
     try {
       URL url = system.getResource(FILE_PATH);
       String versionInFile = Resources.toString(url, StandardCharsets.UTF_8);
-      return new SonarQubeVersion(Version.parse(versionInFile), product, sonarQubeSide);
+      return Version.parse(versionInFile);
     } catch (IOException e) {
       throw new IllegalStateException("Can not load " + FILE_PATH + " from classpath", e);
     }
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/internal/SonarRuntimeImpl.java b/sonar-plugin-api/src/main/java/org/sonar/api/internal/SonarRuntimeImpl.java
new file mode 100644
index 00000000000..601c8d017c2
--- /dev/null
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/internal/SonarRuntimeImpl.java
@@ -0,0 +1,83 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2016 SonarSource SA
+ * mailto:contact 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.internal;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+import org.sonar.api.SonarProduct;
+import org.sonar.api.SonarQubeSide;
+import org.sonar.api.SonarRuntime;
+import org.sonar.api.utils.Version;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static java.util.Objects.requireNonNull;
+
+/**
+ * @since 6.0
+ */
+@Immutable
+public class SonarRuntimeImpl implements SonarRuntime {
+
+  private final Version version;
+  private final SonarProduct product;
+  private final SonarQubeSide sonarQubeSide;
+
+  private SonarRuntimeImpl(Version version, SonarProduct product, @Nullable SonarQubeSide sonarQubeSide) {
+    requireNonNull(version);
+    requireNonNull(product);
+    checkArgument((product == SonarProduct.SONARQUBE) == (sonarQubeSide != null), "sonarQubeSide should be provided only for SonarQube product");
+    this.version = version;
+    this.product = product;
+    this.sonarQubeSide = sonarQubeSide;
+  }
+
+  @Override
+  public Version getApiVersion() {
+    return this.version;
+  }
+
+  @Override
+  public SonarProduct getProduct() {
+    return product;
+  }
+
+  @Override
+  public SonarQubeSide getSonarQubeSide() {
+    if (sonarQubeSide == null) {
+      throw new UnsupportedOperationException("Can only be called in SonarQube");
+    }
+    return sonarQubeSide;
+  }
+
+  /**
+   * Create an instance for SonarQube runtime environment.
+   */
+  public static SonarRuntime forSonarQube(Version version, SonarQubeSide side) {
+    return new SonarRuntimeImpl(version, SonarProduct.SONARQUBE, side);
+  }
+
+  /**
+   * Create an instance for SonarLint runtime environment.
+   */
+  public static SonarRuntime forSonarLint(Version version) {
+    return new SonarRuntimeImpl(version, SonarProduct.SONARLINT, null);
+  }
+
+}
diff --git a/sonar-plugin-api/src/main/java/org/sonar/api/platform/Server.java b/sonar-plugin-api/src/main/java/org/sonar/api/platform/Server.java
index 8d52dce62d5..f8aa4bd2a2c 100644
--- a/sonar-plugin-api/src/main/java/org/sonar/api/platform/Server.java
+++ b/sonar-plugin-api/src/main/java/org/sonar/api/platform/Server.java
@@ -27,24 +27,62 @@ import org.sonar.api.ce.ComputeEngineSide;
 import org.sonar.api.server.ServerSide;
 
 /**
+ * Runtime information about server
+ *
  * @since 2.2
-  */
+ */
 @ScannerSide
 @ServerSide
 @ComputeEngineSide
 public abstract class Server {
 
+  /**
+   * Name is misleading, this is an UUID generated
+   * at each startup, so it changes if server is restarted.
+   * @return a non-null UUID. Format can change over versions.
+   */
   public abstract String getId();
 
+  /**
+   * UUID generated on demand by system administrators. It is
+   * {@code null} by default on fresh installations. When defined,
+   * value does not change when server is restarted.
+   * @since 2.10
+   */
+  @CheckForNull
+  public abstract String getPermanentServerId();
+
+  /**
+   * Non-null version of SonarQube at runtime
+   */
   public abstract String getVersion();
 
+  /**
+   * Date when server started
+   */
   public abstract Date getStartedAt();
 
+  /**
+   * @deprecated in 6.0. Replaced by {@link ServerFileSystem#getHomeDir()}
+   * @return an existing directory in server and CE environments, {@code null} in scanner.
+   */
+  @Deprecated
   public abstract File getRootDir();
 
+  /**
+   * @deprecated always {@code null} since version 6.0. No alternatives, as plugins do not have to touch this directory.
+   */
+  @Deprecated
   @CheckForNull
   public abstract File getDeployDir();
 
+  /**
+   * Context path of web server. Value is blank {@code ""} by default. When defined by
+   * the property {@code sonar.web.context} of conf/sonar.properties, then value starts but does
+   * not end with slash {@code '/'}, for instance {@code "/sonarqube"}.
+   *
+   * @return non-null but possibly blank path
+   */
   public abstract String getContextPath();
 
   /**
@@ -56,7 +94,7 @@ public abstract class Server {
   public abstract String getPublicRootUrl();
 
   /**
-   * The dev mode is enabled when the property sonar.web.dev is true.
+   * The dev mode is enabled when the property {@code sonar.web.dev} is {@code true}.
    *
    * @since 5.4
    */
@@ -76,9 +114,4 @@ public abstract class Server {
    * @since since 2.4 on batch side only, since 5.6 on both batch side and server side (WebServer and Compute Engine)
    */
   public abstract String getURL();
-
-  /**
-   * @since 2.10
-   */
-  public abstract String getPermanentServerId();
 }
diff --git a/sonar-plugin-api/src/test/java/org/sonar/api/PluginTest.java b/sonar-plugin-api/src/test/java/org/sonar/api/PluginTest.java
index caa022c0290..2ef2d212e59 100644
--- a/sonar-plugin-api/src/test/java/org/sonar/api/PluginTest.java
+++ b/sonar-plugin-api/src/test/java/org/sonar/api/PluginTest.java
@@ -21,17 +21,21 @@ package org.sonar.api;
 
 import java.util.Arrays;
 import org.junit.Test;
+import org.sonar.api.internal.SonarRuntimeImpl;
+import org.sonar.api.utils.Version;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.sonar.api.SonarRuntime.V5_5;
 
 public class PluginTest {
 
+  private static final Version VERSION_5_6 = Version.create(5, 6);
+
   @Test
   public void test_context() {
-    Plugin.Context context = new Plugin.Context(new SonarRuntime(V5_5, SonarProduct.SONARQUBE, SonarQubeSide.SERVER));
+    SonarRuntime runtime = SonarRuntimeImpl.forSonarQube(VERSION_5_6, SonarQubeSide.SERVER);
+    Plugin.Context context = new Plugin.Context(runtime);
 
-    assertThat(context.getSonarQubeVersion()).isEqualTo(V5_5);
+    assertThat(context.getSonarQubeVersion()).isEqualTo(VERSION_5_6);
     assertThat(context.getExtensions()).isEmpty();
 
     context.addExtension("foo");
diff --git a/sonar-plugin-api/src/test/java/org/sonar/api/SonarQubeVersionTest.java b/sonar-plugin-api/src/test/java/org/sonar/api/SonarQubeVersionTest.java
index 8ee63aa98fd..ac430ad82f5 100644
--- a/sonar-plugin-api/src/test/java/org/sonar/api/SonarQubeVersionTest.java
+++ b/sonar-plugin-api/src/test/java/org/sonar/api/SonarQubeVersionTest.java
@@ -19,22 +19,17 @@
  */
 package org.sonar.api;
 
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.sonar.api.utils.Version;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class SonarQubeVersionTest {
 
-  @Rule
-  public ExpectedException expectedException = ExpectedException.none();
-
   @Test
   public void isGte() {
     Version version = Version.parse("1.2.3");
-    SonarQubeVersion qubeVersion = new SonarQubeVersion(version, SonarProduct.SONARLINT, null);
+    SonarQubeVersion qubeVersion = new SonarQubeVersion(version);
     assertThat(qubeVersion.get()).isEqualTo(version);
     assertThat(qubeVersion.isGreaterThanOrEqual(version)).isTrue();
     assertThat(qubeVersion.isGreaterThanOrEqual(Version.parse("1.1"))).isTrue();
diff --git a/sonar-plugin-api/src/test/java/org/sonar/api/internal/SonarRuntimeFactoryTest.java b/sonar-plugin-api/src/test/java/org/sonar/api/internal/ApiVersionTest.java
index 4db26447ca5..996b0648ddf 100644
--- a/sonar-plugin-api/src/test/java/org/sonar/api/internal/SonarRuntimeFactoryTest.java
+++ b/sonar-plugin-api/src/test/java/org/sonar/api/internal/ApiVersionTest.java
@@ -23,26 +23,24 @@ import java.io.File;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
-import org.sonar.api.SonarProduct;
-import org.sonar.api.SonarQubeVersion;
 import org.sonar.api.utils.System2;
+import org.sonar.api.utils.Version;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.when;
 
-public class SonarRuntimeFactoryTest {
+public class ApiVersionTest {
 
   @Rule
   public ExpectedException expectedException = ExpectedException.none();
 
   @Test
-  public void create() {
-    SonarQubeVersion version = SonarRuntimeFactory.create(System2.INSTANCE, SonarProduct.SONARLINT, null);
+  public void load_version_from_file_in_classpath() {
+    Version version = ApiVersion.load(System2.INSTANCE);
     assertThat(version).isNotNull();
-    assertThat(version.getApiVersion().major()).isGreaterThanOrEqualTo(5);
-    assertThat(version.getProduct()).isEqualTo(SonarProduct.SONARLINT);
+    assertThat(version.major()).isGreaterThanOrEqualTo(5);
   }
 
   @Test
@@ -52,7 +50,7 @@ public class SonarRuntimeFactoryTest {
 
     System2 system = spy(System2.class);
     when(system.getResource(anyString())).thenReturn(new File("target/unknown").toURI().toURL());
-    SonarRuntimeFactory.create(system, SonarProduct.SONARLINT, null);
+    ApiVersion.load(system);
   }
 
 }
diff --git a/sonar-plugin-api/src/test/java/org/sonar/api/SonarRuntimeTest.java b/sonar-plugin-api/src/test/java/org/sonar/api/internal/SonarRuntimeImplTest.java
index 6d26a5678ce..ea214d5bef1 100644
--- a/sonar-plugin-api/src/test/java/org/sonar/api/SonarRuntimeTest.java
+++ b/sonar-plugin-api/src/test/java/org/sonar/api/internal/SonarRuntimeImplTest.java
@@ -17,42 +17,40 @@
  * 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;
+package org.sonar.api.internal;
 
 import org.assertj.core.api.Assertions;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
+import org.sonar.api.SonarProduct;
+import org.sonar.api.SonarQubeSide;
+import org.sonar.api.SonarRuntime;
 import org.sonar.api.utils.Version;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-public class SonarRuntimeTest {
+
+public class SonarRuntimeImplTest {
+
+  private static final Version A_VERSION = Version.parse("6.0");
 
   @Rule
   public ExpectedException expectedException = ExpectedException.none();
 
   @Test
-  public void isGteInSQ() {
-    Version version = Version.parse("1.2.3");
-    SonarRuntime apiVersion = new SonarRuntime(version, SonarProduct.SONARQUBE, SonarQubeSide.SCANNER);
-    assertThat(apiVersion.getApiVersion()).isEqualTo(version);
+  public void sonarQube_environment() {
+    SonarRuntime apiVersion = SonarRuntimeImpl.forSonarQube(A_VERSION, SonarQubeSide.SCANNER);
+    assertThat(apiVersion.getApiVersion()).isEqualTo(A_VERSION);
     assertThat(apiVersion.getProduct()).isEqualTo(SonarProduct.SONARQUBE);
     assertThat(apiVersion.getSonarQubeSide()).isEqualTo(SonarQubeSide.SCANNER);
-    assertThat(apiVersion.isGreaterThanOrEqual(version)).isTrue();
-    assertThat(apiVersion.isGreaterThanOrEqual(Version.parse("1.1"))).isTrue();
-    assertThat(apiVersion.isGreaterThanOrEqual(Version.parse("1.3"))).isFalse();
   }
 
   @Test
-  public void inSL() {
-    Version version = Version.parse("1.2.3");
-    SonarRuntime apiVersion = new SonarRuntime(version, SonarProduct.SONARLINT, null);
-    assertThat(apiVersion.getApiVersion()).isEqualTo(version);
+  public void sonarLint_environment() {
+    SonarRuntime apiVersion = SonarRuntimeImpl.forSonarLint(A_VERSION);
+    assertThat(apiVersion.getApiVersion()).isEqualTo(A_VERSION);
     assertThat(apiVersion.getProduct()).isEqualTo(SonarProduct.SONARLINT);
-    assertThat(apiVersion.isGreaterThanOrEqual(version)).isTrue();
-    assertThat(apiVersion.isGreaterThanOrEqual(Version.parse("1.1"))).isTrue();
-    assertThat(apiVersion.isGreaterThanOrEqual(Version.parse("1.3"))).isFalse();
     try {
       apiVersion.getSonarQubeSide();
       Assertions.fail("Expected exception");
@@ -62,12 +60,10 @@ public class SonarRuntimeTest {
   }
 
   @Test(expected = IllegalArgumentException.class)
-  public void testConstructorMissSide() throws Exception {
-    new SonarRuntime(Version.parse("1.2.3"), SonarProduct.SONARQUBE, null);
+  public void sonarqube_requires_side() throws Exception {
+    SonarRuntimeImpl.forSonarQube(A_VERSION, null);
   }
 
-  @Test(expected = IllegalArgumentException.class)
-  public void testConstructorNoSideOnSonarLint() throws Exception {
-    new SonarRuntime(Version.parse("1.2.3"), SonarProduct.SONARLINT, SonarQubeSide.COMPUTE_ENGINE);
-  }
+
+
 }