Add IDBKeyRange to dart:html, port two indexeddb tests

tests/html/indexeddb_3_test.dart

+#library('IndexedDB3Test');
+#import('../../lib/unittest/unittest.dart');
+#import('../../lib/unittest/html_config.dart');
+#import('dart:html');
+
+// Read with cursor.
+
+final String DB_NAME = 'Test';
+final String STORE_NAME = 'TEST';
+final String VERSION = '1';
+
+class Test {
+  var db;
+
+  start() {
+    var request = window.webkitIndexedDB.open(DB_NAME);
+    Expect.isNotNull(request);
+    request.on.success.add(initDb);
+    request.on.error.add(fail('open'));
+  }
+
+  initDb(e) {
+    db = e.target.result;
+    // TODO.  Some browsers do this the w3 way - passing the VERSION to the
+    // open call and listening to onversionchange.  Can we feature-detect the
+    // difference and make it work?
+    var request = db.setVersion(VERSION);
+    request.on.success.add((e) {
+        try {
+          // Nuke object store if it already exists.
+          db.deleteObjectStore(STORE_NAME);
+        } catch (IDBDatabaseException e) { }
+        db.createObjectStore(STORE_NAME);
+        writeItems(0);
+      });
+    request.on.error.add(fail('setVersion error'));
+  }
+
+  writeItems(int index) {
+    if (index < 100) {
+      var transaction = db.transaction([STORE_NAME], IDBTransaction.READ_WRITE);
+      var request = transaction.objectStore(STORE_NAME)
+          .put('Item $index', index);
+      request.on.success.add((e) { writeItems(index + 1); });
+      request.on.error.add(fail('put'));
+    } else {
+      callbackDone();
+    }
+  }
+
+  fail(message) => (e) {
+    callbackDone();
+    Expect.fail('IndexedDB failure: $message');
+  };
+
+  readAllViaCursor() {
+    IDBTransaction txn = db.transaction(STORE_NAME, IDBTransaction.READ_ONLY);
+    IDBObjectStore objectStore = txn.objectStore(STORE_NAME);
+    IDBRequest cursorRequest = objectStore.openCursor();
+    int itemCount = 0;
+    int sumKeys = 0;
+    int lastKey = null;
+    cursorRequest.on.success.add((e) {
+        var cursor = e.target.result;
+        if (cursor != null) {
+          lastKey = cursor.key;
+          itemCount += 1;
+          sumKeys += cursor.key;
+          Expect.equals('Item ${cursor.key.toStringAsFixed(0)}', cursor.value);
+          cursor.continueFunction();
+        } else {
+          // Done
+          Expect.equals(99, lastKey);
+          Expect.equals(100, itemCount);
+          Expect.equals((100 * 99) ~/ 2, sumKeys);
+          callbackDone();
+        }
+      });
+    cursorRequest.on.error.add(fail('openCursor'));
+  }
+
+  readAllReversedViaCursor() {
+    IDBTransaction txn = db.transaction(STORE_NAME, IDBTransaction.READ_ONLY);
+    IDBObjectStore objectStore = txn.objectStore(STORE_NAME);
+    // TODO: create a IDBKeyRange(0,100)
+    IDBRequest cursorRequest = objectStore.openCursor(null, IDBCursor.PREV);
+    int itemCount = 0;
+    int sumKeys = 0;
+    int lastKey = null;
+    cursorRequest.on.success.add((e) {
+        var cursor = e.target.result;
+        if (cursor != null) {
+          lastKey = cursor.key;
+          itemCount += 1;
+          sumKeys += cursor.key;
+          Expect.equals('Item ${cursor.key}', cursor.value);
+          cursor.continueFunction();
+        } else {
+          // Done
+          Expect.equals(0, lastKey);  // i.e. first key (scanned in reverse).
+          Expect.equals(100, itemCount);
+          Expect.equals((100 * 99) ~/ 2, sumKeys);
+          callbackDone();
+        }
+      });
+    cursorRequest.on.error.add(fail('openCursor'));
+  }
+}
+
+main() {
+  useHtmlConfiguration();
+
+  var test = new Test();
+  asyncTest('prepare', 1, test.start);
+  asyncTest('readAll1', 1, test.readAllViaCursor);
+  asyncTest('readAll2', 1, test.readAllReversedViaCursor);
+}