SONAR-6897 Precise if scm data should be copied

In scanner report and for each file we will now explicitely request compute engine to copy previous
SCM data.

3 files changed, 35 insertions, 12 deletions

diff --git a/sonar-scanner-engine/src/main/java/org/sonar/batch/scm/ScmSensor.java b/sonar-scanner-engine/src/main/java/org/sonar/batch/scm/ScmSensor.java
index d6880f11fb3..1fdae7db5ce 100644
--- a/sonar-scanner-engine/src/main/java/org/sonar/batch/scm/ScmSensor.java
+++ b/sonar-scanner-engine/src/main/java/org/sonar/batch/scm/ScmSensor.java
@@ -32,10 +32,13 @@ import org.sonar.api.batch.sensor.SensorContext;
 import org.sonar.api.batch.sensor.SensorDescriptor;
 import org.sonar.api.utils.log.Logger;
 import org.sonar.api.utils.log.Loggers;
+import org.sonar.batch.index.BatchComponent;
 import org.sonar.batch.index.BatchComponentCache;
 import org.sonar.batch.report.ReportPublisher;
 import org.sonar.batch.repository.FileData;
 import org.sonar.batch.repository.ProjectRepositories;
+import org.sonar.scanner.protocol.output.ScannerReport;
+import org.sonar.scanner.protocol.output.ScannerReport.Changesets.Builder;
 
 public final class ScmSensor implements Sensor {
 
@@ -45,16 +48,16 @@ public final class ScmSensor implements Sensor {
   private final ScmConfiguration configuration;
   private final FileSystem fs;
   private final ProjectRepositories projectRepositories;
-  private final BatchComponentCache resourceCache;
+  private final BatchComponentCache componentCache;
   private final ReportPublisher publishReportJob;
 
   public ScmSensor(ProjectDefinition projectDefinition, ScmConfiguration configuration,
-    ProjectRepositories projectRepositories, FileSystem fs, BatchComponentCache resourceCache, ReportPublisher publishReportJob) {
+    ProjectRepositories projectRepositories, FileSystem fs, BatchComponentCache componentCache, ReportPublisher publishReportJob) {
     this.projectDefinition = projectDefinition;
     this.configuration = configuration;
     this.projectRepositories = projectRepositories;
     this.fs = fs;
-    this.resourceCache = resourceCache;
+    this.componentCache = componentCache;
     this.publishReportJob = publishReportJob;
   }
 
@@ -78,7 +81,7 @@ public final class ScmSensor implements Sensor {
     if (!filesToBlame.isEmpty()) {
       String key = configuration.provider().key();
       LOG.info("SCM provider for this project is: " + key);
-      DefaultBlameOutput output = new DefaultBlameOutput(publishReportJob.getWriter(), resourceCache, filesToBlame);
+      DefaultBlameOutput output = new DefaultBlameOutput(publishReportJob.getWriter(), componentCache, filesToBlame);
       try {
         configuration.provider().blameCommand().blame(new DefaultBlameInput(fs, filesToBlame), output);
       } catch (Exception e) {
@@ -102,12 +105,22 @@ public final class ScmSensor implements Sensor {
         FileData fileData = projectRepositories.fileData(projectDefinition.getKeyWithBranch(), f.relativePath());
         if (StringUtils.isEmpty(fileData.revision())) {
           addIfNotEmpty(filesToBlame, f);
+        } else {
+          askToCopyDataFromPreviousAnalysis(f);
         }
       }
     }
     return filesToBlame;
   }
 
+  private void askToCopyDataFromPreviousAnalysis(InputFile f) {
+    BatchComponent batchComponent = componentCache.get(f);
+    Builder scmBuilder = ScannerReport.Changesets.newBuilder();
+    scmBuilder.setComponentRef(batchComponent.batchId());
+    scmBuilder.setCopyFromPrevious(true);
+    publishReportJob.getWriter().writeComponentChangesets(scmBuilder.build());
+  }
+
   private static void addIfNotEmpty(List<InputFile> filesToBlame, InputFile f) {
     if (!f.isEmpty()) {
       filesToBlame.add(f);
diff --git a/sonar-scanner-engine/src/test/java/org/sonar/batch/mediumtest/scm/ScmMediumTest.java b/sonar-scanner-engine/src/test/java/org/sonar/batch/mediumtest/scm/ScmMediumTest.java
index 8481c17d3ff..2f045e2adfb 100644
--- a/sonar-scanner-engine/src/test/java/org/sonar/batch/mediumtest/scm/ScmMediumTest.java
+++ b/sonar-scanner-engine/src/test/java/org/sonar/batch/mediumtest/scm/ScmMediumTest.java
@@ -47,6 +47,7 @@ public class ScmMediumTest {
 
   private static final String MISSING_BLAME_INFORMATION_FOR_THE_FOLLOWING_FILES = "Missing blame information for the following files:";
   private static final String CHANGED_CONTENT_SCM_ON_SERVER_XOO = "src/changed_content_scm_on_server.xoo";
+  private static final String NO_BLAME_SCM_ON_SERVER_XOO = "src/no_blame_scm_on_server.xoo";
   private static final String SAME_CONTENT_SCM_ON_SERVER_XOO = "src/same_content_scm_on_server.xoo";
   private static final String SAME_CONTENT_NO_SCM_ON_SERVER_XOO = "src/same_content_no_scm_on_server.xoo";
   private static final String SAMPLE_XOO_CONTENT = "Sample xoo\ncontent";
@@ -66,6 +67,7 @@ public class ScmMediumTest {
     .addFileData("com.foo.project", CHANGED_CONTENT_SCM_ON_SERVER_XOO, new FileData(DigestUtils.md5Hex(SAMPLE_XOO_CONTENT), null))
     .addFileData("com.foo.project", SAME_CONTENT_NO_SCM_ON_SERVER_XOO, new FileData(DigestUtils.md5Hex(SAMPLE_XOO_CONTENT), null))
     .addFileData("com.foo.project", SAME_CONTENT_SCM_ON_SERVER_XOO, new FileData(DigestUtils.md5Hex(SAMPLE_XOO_CONTENT), "1.1"))
+    .addFileData("com.foo.project", NO_BLAME_SCM_ON_SERVER_XOO, new FileData(DigestUtils.md5Hex(SAMPLE_XOO_CONTENT), "1.1"))
     .build();
 
   @Before
@@ -205,6 +207,10 @@ public class ScmMediumTest {
     FileUtils.write(sameContentScmOnServer, SAMPLE_XOO_CONTENT);
     // No need to write .scm file since this file should not be blamed
 
+    File noBlameScmOnServer = new File(baseDir, NO_BLAME_SCM_ON_SERVER_XOO);
+    FileUtils.write(noBlameScmOnServer, SAMPLE_XOO_CONTENT + "\nchanged");
+    // No .scm file to emulate a failure during blame
+
     File sameContentNoScmOnServer = new File(baseDir, SAME_CONTENT_NO_SCM_ON_SERVER_XOO);
     FileUtils.write(sameContentNoScmOnServer, SAMPLE_XOO_CONTENT);
     xooScmFile = new File(baseDir, SAME_CONTENT_NO_SCM_ON_SERVER_XOO + ".scm");
@@ -228,14 +234,16 @@ public class ScmMediumTest {
 
     assertThat(getChangesets(baseDir, "src/sample.xoo")).isNotNull();
 
-    assertThat(getChangesets(baseDir, CHANGED_CONTENT_SCM_ON_SERVER_XOO)).isNotNull();
+    assertThat(getChangesets(baseDir, CHANGED_CONTENT_SCM_ON_SERVER_XOO).getCopyFromPrevious()).isFalse();
+
+    assertThat(getChangesets(baseDir, SAME_CONTENT_SCM_ON_SERVER_XOO).getCopyFromPrevious()).isTrue();
 
-    assertThat(getChangesets(baseDir, SAME_CONTENT_SCM_ON_SERVER_XOO)).isNull();
+    assertThat(getChangesets(baseDir, SAME_CONTENT_NO_SCM_ON_SERVER_XOO).getCopyFromPrevious()).isFalse();
 
-    assertThat(getChangesets(baseDir, SAME_CONTENT_NO_SCM_ON_SERVER_XOO)).isNotNull();
+    assertThat(getChangesets(baseDir, NO_BLAME_SCM_ON_SERVER_XOO)).isNull();
 
-    assertThat(logTester.logs()).containsSubsequence("3 files to be analyzed", "3/3 files analyzed");
-    assertThat(logTester.logs()).doesNotContain(MISSING_BLAME_INFORMATION_FOR_THE_FOLLOWING_FILES);
+    assertThat(logTester.logs()).containsSubsequence("4 files to be analyzed", "3/4 files analyzed");
+    assertThat(logTester.logs()).containsSubsequence(MISSING_BLAME_INFORMATION_FOR_THE_FOLLOWING_FILES, "  * " + noBlameScmOnServer.getPath().replaceAll("\\\\", "/"));
   }
 
   @Test
diff --git a/sonar-scanner-protocol/src/main/protobuf/scanner_report.proto b/sonar-scanner-protocol/src/main/protobuf/scanner_report.proto
index f7ef467f06b..d58fc8d4518 100644
--- a/sonar-scanner-protocol/src/main/protobuf/scanner_report.proto
+++ b/sonar-scanner-protocol/src/main/protobuf/scanner_report.proto
@@ -84,7 +84,7 @@ message Component {
   // Only available on PROJECT and MODULE types
   string version = 9;
   // Only available on PROJECT and MODULE types
-  // TODO rename this property -> batchKey ? moduleKey ?
+  // TODO rename this property -> moduleKey ?
   string key = 10;
   // Only available on FILE type
   int32 lines = 11;
@@ -162,9 +162,11 @@ message Flow {
 
 message Changesets {
   int32 component_ref = 1;
-  repeated Changeset changeset = 2;
+  // If set to true then it means changeset attribute is empty and compute engine should copy data from previous analysis
+  bool copy_from_previous = 2;
+  repeated Changeset changeset = 3;
   // if changesetIndexByLine[5] = 2 then it means that changeset[2] is the last one on line 6
-  repeated int32 changesetIndexByLine = 3 [packed = true];
+  repeated int32 changesetIndexByLine = 4 [packed = true];
 
   message Changeset {
     string revision = 1;