keep select migration strategy in case of an error

scm-webapp/src/main/java/sonia/scm/update/MigrationWizardServlet.java

@@ -4,6 +4,7 @@ import com.github.mustachejava.DefaultMustacheFactory;
 import com.github.mustachejava.Mustache;
 import com.github.mustachejava.MustacheFactory;
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Strings;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import sonia.scm.boot.RestartEvent;
@@ -71,9 +72,16 @@ class MigrationWizardServlet extends HttpServlet {
     boolean validationErrorFound = false;
     for (RepositoryLineEntry repositoryLineEntry : repositoryLineEntries) {
       String id = repositoryLineEntry.getId();
+
+      String strategy = req.getParameter("strategy-" + id);
+      if (!Strings.isNullOrEmpty(strategy)) {
+        repositoryLineEntry.setSelectedStrategy(MigrationStrategy.valueOf(strategy));
+      }
+
       String namespace = req.getParameter("namespace-" + id);
-      String name = req.getParameter("name-" + id);
       repositoryLineEntry.setNamespace(namespace);
+
+      String name = req.getParameter("name-" + id);
       repositoryLineEntry.setName(name);
 
       if (!ValidationUtil.isRepositoryNameValid(namespace)) {
@@ -144,6 +152,7 @@ class MigrationWizardServlet extends HttpServlet {
     private final String id;
     private final String type;
     private final String path;
+    private MigrationStrategy selectedStrategy;
     private String namespace;
     private String name;
     private boolean namespaceValid = true;
@@ -153,6 +162,7 @@ class MigrationWizardServlet extends HttpServlet {
       this.id = repository.getId();
       this.type = repository.getType();
       this.path = repository.getType() + "/" + repository.getName();
+      this.selectedStrategy = MigrationStrategy.COPY;
       this.namespace = computeNewNamespace(repository);
       this.name = computeNewName(repository);
     }
@@ -195,6 +205,17 @@ class MigrationWizardServlet extends HttpServlet {
       return name;
     }
 
+    public MigrationStrategy getSelectedStrategy() {
+      return selectedStrategy;
+    }
+
+    public List<RepositoryLineMigrationStrategy> getStrategies() {
+      return Arrays.asList(MigrationStrategy.values())
+        .stream()
+        .map(s -> new RepositoryLineMigrationStrategy(s.name(), selectedStrategy == s))
+        .collect(Collectors.toList());
+    }
+
     public void setNamespace(String namespace) {
       this.namespace = namespace;
     }
@@ -211,6 +232,10 @@ class MigrationWizardServlet extends HttpServlet {
       this.nameValid = nameValid;
     }
 
+    public void setSelectedStrategy(MigrationStrategy selectedStrategy) {
+      this.selectedStrategy = selectedStrategy;
+    }
+
     public boolean isNamespaceInvalid() {
       return !namespaceValid;
     }
@@ -219,4 +244,23 @@ class MigrationWizardServlet extends HttpServlet {
       return !nameValid;
     }
   }
+
+  private static class RepositoryLineMigrationStrategy {
+
+    private final String name;
+    private final boolean selected;
+
+    private RepositoryLineMigrationStrategy(String name, boolean selected) {
+      this.name = name;
+      this.selected = selected;
+    }
+
+    public String getName() {
+      return name;
+    }
+
+    public boolean isSelected() {
+      return selected;
+    }
+  }
 }

scm-webapp/src/main/resources/templates/repository-migration.mustache

@@ -74,7 +74,7 @@
               <div class="control select">
                 <select class="strategy-select" name="strategy-{{id}}">
                   {{#strategies}}
-                    <option>{{name}}</option>
+                    <option{{#selected}} selected{{/selected}}>{{name}}</option>
                   {{/strategies}}
                 </select>
               </div>

scm-webapp/src/test/java/sonia/scm/update/MigrationWizardServletTest.java

@@ -157,6 +157,7 @@ class MigrationWizardServletTest {
     );
     doReturn("invalid namespace").when(request).getParameter("namespace-id");
     doReturn("invalid name").when(request).getParameter("name-id");
+    doReturn("COPY").when(request).getParameter("strategy-id");
 
     servlet.doPost(request, response);
 
@@ -171,6 +172,42 @@ class MigrationWizardServletTest {
       .contains(true);
   }
 
+  @Test
+  void shouldKeepSelectedMigrationStrategy() {
+    when(updateStep.getRepositoriesWithoutMigrationStrategies()).thenReturn(
+      Collections.singletonList(new V1Repository("id", "git", "name"))
+    );
+
+    doReturn("we need an").when(request).getParameter("namespace-id");
+    doReturn("error for this test").when(request).getParameter("name-id");
+    doReturn("INLINE").when(request).getParameter("strategy-id");
+
+    servlet.doPost(request, response);
+
+    assertThat(renderedModel.get("repositories"))
+      .asList()
+      .extracting("selectedStrategy")
+      .contains(MigrationStrategy.INLINE);
+  }
+
+  @Test
+  void shouldUseCopyWithoutMigrationStrategy() {
+    when(updateStep.getRepositoriesWithoutMigrationStrategies()).thenReturn(
+      Collections.singletonList(new V1Repository("id", "git", "name"))
+    );
+
+    doReturn("we need an").when(request).getParameter("namespace-id");
+    doReturn("error for this test").when(request).getParameter("name-id");
+    doReturn("").when(request).getParameter("strategy-id");
+
+    servlet.doPost(request, response);
+
+    assertThat(renderedModel.get("repositories"))
+      .asList()
+      .extracting("selectedStrategy")
+      .contains(MigrationStrategy.COPY);
+  }
+
   @Test
   void shouldStoreValidMigration() {
     when(updateStep.getRepositoriesWithoutMigrationStrategies()).thenReturn(