SONAR-11620 Add scm based file exclusion method to plugin api

sonar-plugin-api/src/main/java/org/sonar/api/batch/scm/IgnoreCommand.java

@@ -0,0 +1,55 @@
+/*
+ * SonarQube
+ * Copyright (C) 2009-2019 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.scm;
+
+import java.nio.file.Path;
+import org.sonar.api.scanner.ScannerSide;
+
+/**
+ * @since 7.6
+ */
+@ScannerSide
+public interface IgnoreCommand {
+
+  /**
+   * Check if a file is ignored by the scm.
+   * {@link #init(Path)} must be called before the first call to this method and {@link #clean()} after the last one
+   *
+   * @param file Absolute path of a project file
+   * @return true if the given file is ignored by the scm, false otherwise
+   */
+  boolean isIgnored(Path file);
+
+  /**
+   * Must be called before the calling {@link #isIgnored(Path)}
+   *
+   * It should contains any operation (e.g. building cache) required before handling {@link #isIgnored(Path)} calls.
+   *
+   * @param baseDir the root directory of the project
+   */
+  void init(Path baseDir);
+
+  /**
+   * To be called after the last call to {@link #isIgnored(Path)}.
+   *
+   * Cache or any other resources used should be cleared.
+   */
+  void clean();
+}

sonar-plugin-api/src/main/java/org/sonar/api/batch/scm/ScmProvider.java

@@ -87,6 +87,10 @@ public abstract class ScmProvider {
     throw new UnsupportedOperationException(formatUnsupportedMessage("Getting relative path from SCM root"));
   }
 
+  public IgnoreCommand ignoreCommand() {
+    throw new UnsupportedOperationException(formatUnsupportedMessage("Checking for ignored files"));
+  }
+
   /**
    * The current revision id of the analyzed code,
    * for example the SHA1 of the current HEAD in a Git branch.

sonar-plugin-api/src/test/java/org/sonar/api/batch/scm/ScmProviderTest.java

@@ -57,4 +57,10 @@ public class ScmProviderTest {
     thrown.expect(UnsupportedOperationException.class);
     provider.revisionId(Paths.get("foo"));
   }
+
+  @Test
+  public void default_implementation_does_not_support_ignore() {
+    thrown.expect(UnsupportedOperationException.class);
+    provider.ignoreCommand();
+  }
 }