[MPLUGIN-510] group history per common requirements

maven-plugin-report-plugin/src/it/plugin-report-detect-requirements-history/pom.xml

@@ -24,8 +24,8 @@ under the License.
   <modelVersion>4.0.0</modelVersion>
 
   <groupId>org.apache.maven.plugins</groupId>
-  <artifactId>maven-plugin-report-plugin</artifactId><!-- intentionally reuse plugin's groupId:artifactId to build its releases history -->
-  <version>1.0-SNAPSHOT</version>
+  <artifactId>maven-assembly-plugin</artifactId><!-- intentionally reuse plugin's groupId:artifactId to build its releases history -->
+  <version>3.7.1-SNAPSHOT</version>
   <packaging>maven-plugin</packaging>
 
   <name>MPLUGIN-511</name>
@@ -84,6 +84,9 @@ under the License.
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-plugin-report-plugin</artifactId>
         <version>@project.version@</version>
+        <configuration>
+          <requirementsHistoryDetectionRange>[3,3.7.0]</requirementsHistoryDetectionRange>
+        </configuration>
       </plugin>
     </plugins>
   </reporting>

maven-plugin-report-plugin/src/it/plugin-report-detect-requirements-history/verify.groovy

@@ -22,8 +22,6 @@ assert new File( basedir, 'target/site/noop-mojo.html' ).isFile()
 def pluginInfo = new File( basedir, 'target/site/plugin-info.html' )
 assert pluginInfo.isFile()
 
-assert pluginInfo.text.contains('3.11.0')
-assert pluginInfo.text.contains('3.10.2')
-assert pluginInfo.text.contains('3.9.0')
-assert pluginInfo.text.contains('3.7.0')
+assert pluginInfo.text.contains('from 3.4.0 to 3.6.0')
+assert pluginInfo.text.contains('>3.2.5<')
 assert pluginInfo.text.contains('>8<')

maven-plugin-report-plugin/src/main/java/org/apache/maven/plugin/plugin/report/PluginOverviewRenderer.java

@@ -211,11 +211,32 @@ private void renderRequirementsHistoriesSection() {
             getI18nString("systemrequirements.history.jdk")
         });
 
+        // group by same requirements
+        final List<List<RequirementsHistory>> requirementsVersions = new ArrayList<>();
         requirementsHistories.forEach(requirementsHistory -> {
+            List<RequirementsHistory> current =
+                    requirementsVersions.isEmpty() ? null : requirementsVersions.get(requirementsVersions.size() - 1);
+            if (current != null && current.get(0).hasSameRequirements(requirementsHistory)) {
+                current.add(requirementsHistory);
+            } else {
+                current = new ArrayList<>();
+                current.add(requirementsHistory);
+                requirementsVersions.add(current);
+            }
+        });
+
+        // render by common requirements
+        requirementsVersions.forEach(requirementsHistories -> {
             sink.tableRow();
-            tableCell(requirementsHistory.getVersion());
-            tableCell(requirementsHistory.getMaven());
-            tableCell(requirementsHistory.getJdk());
+            RequirementsHistory current = requirementsHistories.get(0);
+            if (requirementsHistories.size() == 1) {
+                tableCell(current.getVersion());
+            } else {
+                RequirementsHistory from = requirementsHistories.get(requirementsHistories.size() - 1);
+                tableCell("from " + from.getVersion() + " to " + current.getVersion());
+            }
+            tableCell(current.getMaven());
+            tableCell(current.getJdk());
             sink.tableRow_();
         });
         endTable();

maven-plugin-report-plugin/src/main/java/org/apache/maven/plugin/plugin/report/PluginReport.java

@@ -189,8 +189,14 @@ protected void executeReport(Locale locale) throws MavenReportException {
             String v = null;
             try {
                 List<Version> versions = discoverVersions(requirementsHistoryDetectionRange);
-                getLog().info("Detecting requirements history for " + requirementsHistoryDetectionRange + ": "
-                        + versions.size());
+                if (versions.isEmpty()) {
+                    getLog().info("No plugin history found for range " + requirementsHistoryDetectionRange);
+                } else {
+                    getLog().info("Detecting plugin requirements history for range "
+                            + requirementsHistoryDetectionRange + ": "
+                            + versions.size() + " releases, from " + versions.get(0) + " to "
+                            + versions.get(versions.size() - 1));
+                }
 
                 Collections.reverse(versions);
                 for (Version version : versions) {

maven-plugin-report-plugin/src/main/java/org/apache/maven/plugin/plugin/report/RequirementsHistory.java

@@ -20,6 +20,7 @@
 
 import java.util.Arrays;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 
 import org.apache.commons.lang3.StringUtils;
@@ -173,4 +174,8 @@ private static String getPluginParameter(Plugin plugin, String parameter) {
 
         return null;
     }
+
+    public boolean hasSameRequirements(RequirementsHistory other) {
+        return Objects.equals(this.maven, other.getMaven()) && Objects.equals(this.jdk, other.getJdk());
+    }
 }