1 files changed, 61 insertions, 0 deletions
diff --git a/testing/web-platform/tests/speculation-rules/prerender/resources/indexedb-utils.js b/testing/web-platform/tests/speculation-rules/prerender/resources/indexedb-utils.js
new file mode 100644
index 0000000000..7c57000d5c
--- /dev/null
+++ b/testing/web-platform/tests/speculation-rules/prerender/resources/indexedb-utils.js
@@ -0,0 +1,61 @@
+const STORAGE_NAME = 'prerender_test';
+const INITIATOR_KEY = 'initiator';
+const INITIATOR_VALUE = INITIATOR_KEY + '_set';
+const PRERENDER_KEY = 'prerender';
+const PRERENDER_VALUE = PRERENDER_KEY + '_set';
+
+async function openIndexedDatabase(t) {
+  return new Promise(resolve => {
+    const request = window.indexedDB.open(STORAGE_NAME);
+    if (t)
+      t.add_cleanup(() => new Promise(resolve => {
+        window.indexedDB.deleteDatabase(STORAGE_NAME);
+        resolve();
+      }));
+    request.onupgradeneeded = e => {
+      const db = e.target.result;
+      const objectStore =
+          db.createObjectStore(STORAGE_NAME, {autoIncrement: true});
+      objectStore.createIndex('key', 'key', {unique: true});
+    };
+    request.onerror = e => {
+      resolve(null);
+    };
+    request.onsuccess = e => {
+      resolve(e.target.result);
+    };
+  });
+}
+
+async function addData(db, key, value) {
+  return new Promise((resolve, reject) => {
+    const transaction = db.transaction(STORAGE_NAME, 'readwrite');
+    const request =
+        transaction.objectStore(STORAGE_NAME).add({'key': key, 'value': value});
+    // Use `transaction.oncomplete` rather than `request.onsuccess` to ensure
+    // that IndexedDB has flushed to disk.
+    transaction.oncomplete = e => {
+      resolve(true);
+    };
+    transaction.onerror = e => {
+      reject(e.target.error);
+    };
+  });
+}
+
+async function readData(db, key) {
+  return new Promise((resolve, reject) => {
+    const transaction = db.transaction(STORAGE_NAME);
+    const request = transaction.objectStore(STORAGE_NAME).index('key').get(key);
+    request.onsuccess = e => {
+      if (e.target.result) {
+        resolve(e.target.result.value);
+      } else {
+        reject(new Error('Empty result.'));
+      }
+    };
+    request.onerror = e => {
+      reject(e.target.error);
+    };
+  });
+}