Issue #2818871 by claudiu.cristea, mikeryan: Allow logging skip row exception messages

core/modules/migrate/src/MigrateExecutable.php

@@ -232,6 +232,9 @@ public function import() {
         if ($e->getSaveToMap()) {
           $id_map->saveIdMapping($row, [], MigrateIdMapInterface::STATUS_IGNORED);
         }
+        if ($message = trim($e->getMessage())) {
+          $this->saveMessage($message, MigrationInterface::MESSAGE_INFORMATIONAL);
+        }
         $save = FALSE;
       }
 

core/modules/migrate/src/Plugin/migrate/source/SourcePluginBase.php

@@ -207,6 +207,9 @@ public function prepareRow(Row $row) {
     catch (MigrateSkipRowException $e) {
       $skip = TRUE;
       $save_to_map = $e->getSaveToMap();
+      if ($message = trim($e->getMessage())) {
+        $this->idMap->saveMessage($row->getSourceIdValues(), $message, MigrationInterface::MESSAGE_INFORMATIONAL);
+      }
     }
 
     // We're explicitly skipping this row - keep track in the map table.

core/modules/migrate/tests/modules/migrate_prepare_row_test/migrate_prepare_row_test.module

@@ -18,9 +18,11 @@ function migrate_prepare_row_test_migrate_prepare_row(Row $row, MigrateSourceInt
   // Test both options for save_to_map.
   $data = $row->getSourceProperty('data');
   if ($data == 'skip_and_record') {
+    // Record mapping but don't record a message.
     throw new MigrateSkipRowException('', TRUE);
   }
   elseif ($data == 'skip_and_dont_record') {
-    throw new MigrateSkipRowException('', FALSE);
+    // Don't record mapping but record a message.
+    throw new MigrateSkipRowException('skip_and_dont_record message', FALSE);
   }
 }

core/modules/migrate/tests/src/Kernel/MigrateSkipRowTest.php

@@ -54,13 +54,24 @@ public function testPrepareRowSkip() {
     $result = $executable->import();
     $this->assertEqual($result, MigrationInterface::RESULT_COMPLETED);
 
+    /** @var \Drupal\migrate\Plugin\MigrateIdMapInterface $id_map_plugin */
     $id_map_plugin = $migration->getIdMap();
     // The first row is recorded in the map as ignored.
     $map_row = $id_map_plugin->getRowBySource(['id' => 1]);
     $this->assertEqual(MigrateIdMapInterface::STATUS_IGNORED, $map_row['source_row_status']);
+    // Check that no message has been logged for the first exception.
+    $messages = $id_map_plugin->getMessageIterator(['id' => 1])->fetchAll();
+    $this->assertEmpty($messages);
+
     // The second row is not recorded in the map.
     $map_row = $id_map_plugin->getRowBySource(['id' => 2]);
     $this->assertFalse($map_row);
+    // Check that the correct message has been logged for the second exception.
+    $messages = $id_map_plugin->getMessageIterator(['id' => 2])->fetchAll();
+    $this->assertCount(1, $messages);
+    $message = reset($messages);
+    $this->assertEquals('skip_and_dont_record message', $message->message);
+    $this->assertEquals(MigrationInterface::MESSAGE_INFORMATIONAL, $message->level);
 
     // Insert a custom processor in the process flow.
     $definition['process']['value'] = [