feat: add callback feature

package.json

@@ -15,7 +15,6 @@
     "test:browser": "vitest --workspace=vitest.workspace.ts"
   },
   "devDependencies": {
-    "@playwright/test": "^1.49.1",
     "@types/node": "^22.10.2",
     "@vitest/browser": "^2.1.8",
     "jsdom": "^25.0.1",

src/sql.spec.ts

@@ -1,15 +1,21 @@
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, vi } from "vitest";
 import { SQLite } from "./sqlite";
 
 describe("SQLite database operations", () => {
   it("should perform database operations and verify exports match", async () => {
     const db = new SQLite();
+
+    const execCallback = vi.fn();
+    db.on("exec", execCallback);
+
     await db.exec(`
       CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT);
       INSERT INTO users (name) VALUES ('Alice'), ('Bob');
     `);
 
     const result = await db.exec(`SELECT * FROM users;`);
+
+    expect(execCallback).toHaveBeenCalledTimes(2);
     expect(result).toBeDefined();
 
     const exportedBytes = await db.export_db();

src/sqlite.ts

@@ -1,10 +1,19 @@
 import sqlite3InitModule from "@sqlite.org/sqlite-wasm";
-import type { BindingSpec, Database, FlexibleString, Sqlite3Static, SqlValue } from "@sqlite.org/sqlite-wasm";
+import type {
+  BindingSpec,
+  Database,
+  FlexibleString,
+  Sqlite3Static,
+  SqlValue,
+} from "@sqlite.org/sqlite-wasm";
+
+type Args = any[];
 
 export class SQLite {
   private db: Database | undefined;
   private sqlite3: Sqlite3Static | undefined;
   private initPromise: Promise<void>;
+  private callbacks: { [key: string]: ((args: Args) => void)[] } = {};
 
   constructor() {
     this.initPromise = this.initialize();
@@ -19,11 +28,35 @@ export class SQLite {
     this.db = new this.sqlite3.oo1.DB(":memory:");
   }
 
-
-  async exec(query: FlexibleString, bind?: BindingSpec): Promise<{ [columnName: string]: SqlValue }[]> {
+  async exec(
+    query: FlexibleString,
+    bind?: BindingSpec,
+  ): Promise<{ [columnName: string]: SqlValue }[]> {
     await this.initPromise;
     if (!this.db) return [];
-    return this.db.exec(query, { bind, rowMode: 'object', returnValue: 'resultRows' });
+    const result = this.db.exec(query, {
+      bind,
+      rowMode: "object",
+      returnValue: "resultRows",
+    });
+
+    this.call("exec", [query, bind, result]);
+
+    return result;
+  }
+
+  private call(event: string, args: Args): void {
+    if (!this.callbacks[event]) return;
+    queueMicrotask(() => {
+      for (const callback of this.callbacks[event]) {
+        callback(args);
+      }
+    });
+  }
+
+  on(event: "exec", callback: (args: Args) => void): void {
+    if (!this.callbacks[event]) this.callbacks[event] = [];
+    this.callbacks[event].push(callback);
   }
 
   async export_db(): Promise<Uint8Array> {