feat(deno/idb): implement IDBObjectStore.get

Author: hasundue

deno/idb/mod.ts

@@ -24,13 +24,14 @@ export interface IDBFactory {
   deleteDatabase(name: string): IDBOpenDBRequest<undefined, null>;
 }
 
+const kv = await Deno.openKv();
+
 export const indexedDB: IDBFactory = {
   open(
     name: string,
     version: number = 1,
   ): IDBOpenDBRequest<IDBDatabase, null> {
     return new _IDBOpenDBRequest(async function () {
-      using kv = await Deno.openKv();
       // Check if the database already exists and is up to date.
       const existed = await kv.get<IDBDatabaseInfo>($.database(name));
       if (existed.value?.version && existed.value.version >= version) {
@@ -68,14 +69,12 @@ export const indexedDB: IDBFactory = {
   },
 
   async databases(): Promise<IDBDatabaseInfo[]> {
-    using kv = await Deno.openKv();
     const iter = kv.list<IDBDatabaseInfo>({ prefix: $.database.prefix });
     return (await Array.fromAsync(iter)).map((it) => it.value);
   },
 
   deleteDatabase(name: string): IDBOpenDBRequest<undefined, null> {
     return new _IDBOpenDBRequest(async () => {
-      using kv = await Deno.openKv();
       await kv.delete($.database(name));
       return undefined;
     }) as IDBOpenDBRequest<undefined, null>;

deno/idb/requests.ts

@@ -8,7 +8,7 @@ import { IDBObjectStore } from "./stores.ts";
 import { AnyIDBTransaction, IDBTransaction } from "./transactions.ts";
 
 export interface IDBRequest<
-  Result,
+  Result = unknown,
   Transaction extends AnyIDBTransaction | null = AnyIDBTransaction | null,
 > extends EventTarget {
   readonly error: DOMException | null;
@@ -21,7 +21,7 @@ export interface IDBRequest<
   onsuccess: EventHandler | null;
 }
 
-export class _IDBRequest<Result> extends EventTarget
+export class _IDBRequest<Result = unknown> extends EventTarget
   implements IDBRequest<Result> {
   constructor(
     readonly source: IDBRequestSource | null,
@@ -65,7 +65,7 @@ export class _IDBRequest<Result> extends EventTarget
   onsuccess: EventHandler | null = null;
 }
 
-type IDBRequestSource = IDBObjectStore | IDBIndex | IDBCursor;
+export type IDBRequestSource = IDBObjectStore | IDBIndex | IDBCursor;
 
 export interface IDBOpenDBRequest<
   Result extends IDBDatabase | undefined = IDBDatabase,

deno/idb/stores.ts

@@ -1,14 +1,11 @@
 import { match, placeholder as _, RegularPlaceholder } from "@core/match";
 import { associateWith } from "@std/collections/associate-with";
 
+import { _IDBDatabase } from "./databases.ts";
 import { _IDBIndex, IDBIndex } from "./indexes.ts";
 import { IDBValidKey, isIDBKey, KvKeyFactoryRecord as $ } from "./keys.ts";
 import { _IDBRequest, IDBRequest } from "./requests.ts";
-import {
-  _IDBTransaction,
-  AnyIDBTransaction,
-  IDBTransaction,
-} from "./transactions.ts";
+import { _IDBTransaction, IDBTransaction } from "./transactions.ts";
 
 export interface IDBObjectStore<
   M extends IDBTransactionMode = IDBTransactionMode,
@@ -28,6 +25,8 @@ export interface IDBObjectStore<
     keyPath: string | string[],
     options?: IDBIndexParameters,
   ) => IDBIndex;
+
+  get(key: IDBValidKey): IDBRequest<unknown>;
 }
 
 /**
@@ -47,6 +46,7 @@ export function _IDBObjectStore<M extends IDBTransactionMode>(
     transaction,
     autoIncrement,
 
+    // @ts-ignore: TS doesn't understand the conditional type
     add: transaction.mode === "readonly" ? undefined : (
       value: unknown,
       key?: IDBValidKey,
@@ -59,9 +59,8 @@ export function _IDBObjectStore<M extends IDBTransactionMode>(
       }
       const result = ensureKey(options, value, key);
       const parts = Array.isArray(result) ? result : [result];
-      return new _IDBRequest<IDBValidKey>(
+      return transaction._createRequest(
         store,
-        transaction as AnyIDBTransaction,
         () => {
           (transaction as _IDBTransaction<M>)._atomic.set(
             $.value(transaction.db.name, name, ...parts),
@@ -72,6 +71,7 @@ export function _IDBObjectStore<M extends IDBTransactionMode>(
       );
     },
 
+    // @ts-ignore: TS doesn't understand the conditional type
     createIndex: transaction.mode !== "versionchange" ? undefined : (
       indexName: string,
       keyPath: string | string[],
@@ -85,6 +85,21 @@ export function _IDBObjectStore<M extends IDBTransactionMode>(
       }
       return new _IDBIndex(indexName, keyPath, options);
     },
+
+    get(key: IDBValidKey): IDBRequest<unknown> {
+      const keyArray = Array.isArray(key) ? key : [key];
+      const request = transaction._createRequest(
+        store,
+        async () => {
+          const kv = (this.transaction.db as _IDBDatabase)._kv;
+          const result = await kv.get(
+            $.value(transaction.db.name, name, ...keyArray),
+          );
+          return result.versionstamp ? result.value : undefined;
+        },
+      );
+      return request;
+    },
   };
   return store;
 }

deno/idb/transactions.ts

@@ -2,6 +2,7 @@ import { DOMStringList } from "@lophus/lib/legacy";
 import { EventHandler } from "./events.ts";
 import { _IDBDatabase, IDBDatabase } from "./databases.ts";
 import { _IDBObjectStore, IDBObjectStore } from "./stores.ts";
+import { _IDBRequest, IDBRequestSource } from "./requests.ts";
 
 export interface IDBTransaction<
   Mode extends IDBTransactionMode = IDBTransactionMode,
@@ -62,4 +63,37 @@ export class _IDBTransaction<Mode extends IDBTransactionMode>
     }
     return _IDBObjectStore(this, name, options);
   }
+
+  /**
+   * An internal method to add a request to the transaction.
+   * @internal
+   */
+  _createRequest<R>(
+    source: IDBRequestSource | null,
+    operation: () => Promise<R>,
+  ): _IDBRequest<R> {
+    if (this._completed) {
+      throw new DOMException(
+        "The transaction has already completed.",
+        "TransactionInactiveError",
+      );
+    }
+    const request = new _IDBRequest<R>(
+      source,
+      this as AnyIDBTransaction,
+      operation,
+    );
+    this._requests.add(request);
+    request.addEventListener("success", async () => {
+      this._requests.delete(request);
+      if (this._requests.size === 0) {
+        await this._atomic.commit();
+        this._completed = true;
+        this.dispatchEvent(new Event("complete"));
+      }
+    });
+    return request;
+  }
+  readonly _requests: Set<_IDBRequest> = new Set();
+  _completed: boolean = false;
 }

deno/idb_test.ts

@@ -13,8 +13,8 @@ import {
   it,
 } from "@std/testing/bdd";
 import type {
-  IDBFactory,
   IDBDatabase,
+  IDBFactory,
   IDBIndex,
   IDBObjectStore,
   IDBOpenDBRequest,
@@ -173,11 +173,13 @@ describe('IDBObjectStore<"readonly">', () => {
 
   beforeAll(async () => {
     const request = self.indexedDB.open(name);
-    await new Promise((resolve) => {
-      request.onupgradeneeded = (event) =>
-        resolve(
-          event.target.result.createObjectStore("events", { keyPath: "id" }),
-        );
+    await new Promise<void>((resolve) => {
+      request.onupgradeneeded = (event) => {
+        const db = event.target.result;
+        const store = db.createObjectStore("events", { keyPath: "id" });
+        store.add({ id: 1, pubkey: "pubkey" });
+        resolve();
+      };
     });
     await ensure(request, "success");
     store = request.result.transaction("events", "readonly").objectStore(
@@ -213,6 +215,14 @@ describe('IDBObjectStore<"readonly">', () => {
       );
     });
   });
+
+  describe("get", () => {
+    it("should get an object", async () => {
+      const request = store.get(1);
+      await ensure(store.transaction, "complete");
+      assertEquals(request.result, { id: 1, pubkey: "pubkey" });
+    });
+  });
 });
 
 describe('IDBObjectStore<"readwrite">', () => {
@@ -228,9 +238,9 @@ describe('IDBObjectStore<"readwrite">', () => {
         );
     });
     await ensure(request, "success");
-    store = request.result.transaction("events", "readwrite").objectStore(
-      "events",
-    );
+    store = request.result
+      .transaction("events", "readwrite")
+      .objectStore("events");
   });
 
   afterAll(async () => {
@@ -265,6 +275,13 @@ describe('IDBObjectStore<"readwrite">', () => {
       );
     });
   });
+
+  describe("get", () => {
+    it("should throw a TransactionInactiveError once the transaction is completed", async () => {
+      await ensure(store.transaction, "complete");
+      assertThrows(() => store.get(1));
+    });
+  });
 });
 
 describe('IDBObjectStore<"versionchange">', () => {