don't merge empty files (#3120)

* check for empty datastore indexes * reverse check * remove extra end tag * code rview
GoogleCloudPlatform · May 30, 2018 · cd19cc1 · cd19cc1
1 parent 76131b5
commit cd19cc1
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Showing 2 changed files with 67 additions and 8 deletions.
diff --git a/...google/cloud/tools/eclipse/appengine/localserver/server/DatastoreIndexUpdateDataTest.java b/...google/cloud/tools/eclipse/appengine/localserver/server/DatastoreIndexUpdateDataTest.java
@@ -28,6 +28,10 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IProject;
@@ -70,7 +74,16 @@ public void setUp() throws IOException {
   }
 
   @Test
-  public void testNoUpdate() {
+  public void testNoUpdateWithNoFile() {
+    DatastoreIndexUpdateData update =
+        DatastoreIndexUpdateData.detect(launchConfiguration, server, defaultService);
+    assertNull(update);
+  }
+
+  @Test
+  public void testNoUpdateWithEmptyFile() throws IOException {
+    createEmptyDatastoreIndexesAutoXml();
+
     DatastoreIndexUpdateData update =
         DatastoreIndexUpdateData.detect(launchConfiguration, server, defaultService);
     assertNull(update);
@@ -143,10 +156,32 @@ public void testExistingDatastoreIndexesXml_noUpdate() throws IOException {
     assertNull(update);
   }
 
-  private void createDatastoreIndexesAutoXml() throws IOException {
+  private void createDatastoreIndexesAutoXml() throws IOException {    
+    try (Writer out = openDatastoreIndexesAutoFile()) {
+      out.write("<datastore-indexes>");
+      out.write("<datastore-index kind='Employee' ancestor='false'>");
+      out.write("<property name='lastName' direction='asc' />");
+      out.write("</datastore-index>");
+      out.write("</datastore-indexes>");
+      out.flush();
+    }
+  }
+
+  private Writer openDatastoreIndexesAutoFile() throws IOException {
     File appengineGenerated = new File(webInf, "appengine-generated");
     File datastoreIndexesAutoXml = new File(appengineGenerated, "datastore-indexes-auto.xml");
     assertTrue(appengineGenerated.mkdirs());
     assertTrue(datastoreIndexesAutoXml.createNewFile());
+
+    return new OutputStreamWriter(
+        Files.newOutputStream(datastoreIndexesAutoXml.toPath()),
+        StandardCharsets.UTF_8);
+  }
+
+  private void createEmptyDatastoreIndexesAutoXml() throws IOException {
+    try (Writer out = openDatastoreIndexesAutoFile()) {
+      out.write("<datastore-indexes/>");
+      out.flush();
+    }
   }
 }
diff --git a/...com/google/cloud/tools/eclipse/appengine/localserver/server/DatastoreIndexUpdateData.java b/...com/google/cloud/tools/eclipse/appengine/localserver/server/DatastoreIndexUpdateData.java
@@ -18,15 +18,21 @@
 
 import com.google.cloud.tools.eclipse.appengine.facets.WebProjectUtil;
 import com.google.common.annotations.VisibleForTesting;
+import java.io.IOException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.debug.core.ILaunchConfiguration;
 import org.eclipse.wst.server.core.IModule;
 import org.eclipse.wst.server.core.IServer;
+import org.w3c.dom.Document;
+import org.xml.sax.SAXException;
 
-/** A simple value class to capture that updates to a module's {@code datastore-indexes.xml}. */
+/** A simple value class to capture updates to a module's {@code datastore-indexes.xml}. */
 public class DatastoreIndexUpdateData {
   private static final Logger logger = Logger.getLogger(DatastoreIndexUpdateData.class.getName());
 
@@ -49,13 +55,14 @@ static DatastoreIndexUpdateData detect(ILaunchConfiguration configuration, IServ
     LocalAppEngineServerBehaviour serverBehaviour = (LocalAppEngineServerBehaviour) server
         .loadAdapter(LocalAppEngineServerBehaviour.class, null);
     IPath deployPath = serverBehaviour.getModuleDeployDirectory(defaultService);
-    IPath datastoreIndexesAutoXml = deployPath.append("WEB-INF/appengine-generated/datastore-indexes-auto.xml");
-    if(!datastoreIndexesAutoXml.toFile().exists()) {
+    IPath datastoreIndexesAutoXml =
+        deployPath.append("WEB-INF/appengine-generated/datastore-indexes-auto.xml");
+    if (!indexGenerated(datastoreIndexesAutoXml)) {
       return null;
     }
-    // the datastore-indexes-auto.xml may be generated even if the datastore-indexes.xml does not exist
-    IFile datastoreIndexesXml =
-        WebProjectUtil.findInWebInf(defaultService.getProject(), new org.eclipse.core.runtime.Path("datastore-indexes.xml"));
+    // datastore-indexes-auto.xml may be generated even if datastore-indexes.xml does not exist
+    IFile datastoreIndexesXml = WebProjectUtil.findInWebInf(defaultService.getProject(),
+        new org.eclipse.core.runtime.Path("datastore-indexes.xml"));
 
     if (datastoreIndexesXml != null && datastoreIndexesXml.exists()) {
       long sourceTimestamp = datastoreIndexesXml.getLocalTimeStamp();
@@ -70,6 +77,23 @@ static DatastoreIndexUpdateData detect(ILaunchConfiguration configuration, IServ
         datastoreIndexesAutoXml);
   }
 
+  private static boolean indexGenerated(IPath datastoreIndexesAutoXml) {
+    if (!datastoreIndexesAutoXml.toFile().exists()) { 
+      return false;
+    }
+    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+    factory.setNamespaceAware(true);
+    try {
+      DocumentBuilder builder = factory.newDocumentBuilder();
+      Document doc = builder.parse(datastoreIndexesAutoXml.toFile());
+      return doc.getElementsByTagName("datastore-index").getLength() > 0;
+    } catch (ParserConfigurationException ex) {
+      return true;
+    } catch (SAXException | IOException ex) {
+      return false;
+    }
+  }
+
   public final IServer server;
   public final ILaunchConfiguration configuration;