New Data handler with lowdb

package.json

@@ -9,6 +9,7 @@
     "lint": "next lint"
   },
   "dependencies": {
+    "lowdb": "^7.0.1",
     "match-sorter": "^8.0.0",
     "next": "15.2.4",
     "react": "^19.0.0",

pnpm-lock.yaml

@@ -8,6 +8,9 @@ importers:
 
   .:
     dependencies:
+      lowdb:
+        specifier: ^7.0.1
+        version: 7.0.1
       match-sorter:
         specifier: ^8.0.0
         version: 8.0.0
@@ -1121,6 +1124,10 @@ packages:
     resolution: {integrity: sha512-lyuxPGr/Wfhrlem2CL/UcnUc1zcqKAImBDzukY7Y5F/yQiNdko6+fRLevlw1HgMySw7f611UIY408EtxRSoK3Q==}
     hasBin: true
 
+  lowdb@7.0.1:
+    resolution: {integrity: sha512-neJAj8GwF0e8EpycYIDFqEPcx9Qz4GUho20jWFR7YiFeXzF1YMLdxB36PypcTSPMA+4+LvgyMacYhlr18Zlymw==}
+    engines: {node: '>=18'}
+
   match-sorter@8.0.0:
     resolution: {integrity: sha512-bGJ6Zb+OhzXe+ptP5d80OLVx7AkqfRbtGEh30vNSfjNwllu+hHI+tcbMIT/fbkx/FKN1PmKuDb65+Oofg+XUxw==}
 
@@ -1407,6 +1414,10 @@ packages:
   stable-hash@0.0.5:
     resolution: {integrity: sha512-+L3ccpzibovGXFK+Ap/f8LOS0ahMrHTf3xu7mMLSpEGU0EO9ucaysSylKo9eRDFNhWve/y275iPmIZ4z39a9iA==}
 
+  steno@4.0.2:
+    resolution: {integrity: sha512-yhPIQXjrlt1xv7dyPQg2P17URmXbuM5pdGkpiMB3RenprfiBlvK415Lctfe0eshk90oA7/tNq7WEiMK8RSP39A==}
+    engines: {node: '>=18'}
+
   streamsearch@1.1.0:
     resolution: {integrity: sha512-Mcc5wHehp9aXz1ax6bZUyY5afg9u2rv5cqQI3mRrYkGC8rW2hM02jWuwjtL++LS5qinSyhj2QfLyNsuc+VsExg==}
     engines: {node: '>=10.0.0'}
@@ -2764,6 +2775,10 @@ snapshots:
     dependencies:
       js-tokens: 4.0.0
 
+  lowdb@7.0.1:
+    dependencies:
+      steno: 4.0.2
+
   match-sorter@8.0.0:
     dependencies:
       '@babel/runtime': 7.27.0
@@ -3100,6 +3115,8 @@ snapshots:
 
   stable-hash@0.0.5: {}
 
+  steno@4.0.2: {}
+
   streamsearch@1.1.0: {}
 
   string.prototype.includes@2.0.1:

src/app/data.ts

@@ -2,12 +2,16 @@
 // 🛑 Nothing in here has anything to do with React Router, it's just a fake database
 ////////////////////////////////////////////////////////////////////////////////
 // noinspection UnnecessaryLocalVariableJS,JSUnusedGlobalSymbols
-import "server-only"
+import "server-only";
 
 import { matchSorter } from "match-sorter";
 // @ts-expect-error - no types, but it's a tiny function
 import sortBy from "sort-by";
 import invariant from "tiny-invariant";
+import { Low } from "lowdb";
+import { JSONFile } from "lowdb/node";
+import { join } from "path";
+import { mkdir } from "fs/promises";
 
 type ContactMutation = {
   id?: string;
@@ -24,42 +28,97 @@ export type ContactRecord = ContactMutation & {
   createdAt: string;
 };
 
-////////////////////////////////////////////////////////////////////////////////
+// Define the database schema
-// This is just a fake DB table. In a real app you'd be talking to a real db or
+type Schema = {
-// fetching from an existing API.
+  records: Record<string, ContactRecord>;
-const fakeContacts = {
+};
-  records: {} as Record<string, ContactRecord>,
 
+// Set up lowdb
+const initDb = async (): Promise<Low<Schema>> => {
+  // Ensure the db directory exists
+  const dbDir = join(process.cwd(), '.db');
+  await mkdir(dbDir, { recursive: true });
+
+  const file = join(dbDir, 'contacts.json');
+  const adapter = new JSONFile<Schema>(file);
+  const defaultData: Schema = { records: {} };
+  const db = new Low<Schema>(adapter, defaultData);
+
+  // Load existing data
+  await db.read();
+
+  // Initialize if needed
+  if (!db.data) {
+    db.data = defaultData;
+  }
+
+  return db;
+};
+
+// Create a singleton instance of the database
+let dbPromise: Promise<Low<Schema>> | null = null;
+
+const getDb = () => {
+  if (!dbPromise) {
+    dbPromise = initDb();
+  }
+  return dbPromise;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+// This is a DB wrapper using lowdb for persistence
+const fakeContacts = {
   async getAll(): Promise<ContactRecord[]> {
-    return Object.keys(fakeContacts.records)
+    const db = await getDb();
-      .map((key) => fakeContacts.records[key])
+    return Object.keys(db.data.records)
+      .map((key) => db.data.records[key])
       .sort(sortBy("-createdAt", "last"));
   },
 
   async get(id: string): Promise<ContactRecord | null> {
-    return fakeContacts.records[id] || null;
+    const db = await getDb();
+    return db.data.records[id] || null;
   },
 
   async create(values: ContactMutation): Promise<ContactRecord> {
+    const db = await getDb();
     const id = values.id || Math.random().toString(36).substring(2, 9);
     const createdAt = new Date().toISOString();
     const newContact = { id, createdAt, ...values };
-    fakeContacts.records[id] = newContact;
+    db.data.records[id] = newContact;
+    await db.write();
     return newContact;
   },
 
   async set(id: string, values: ContactMutation): Promise<ContactRecord> {
-    const contact = await fakeContacts.get(id);
+    const db = await getDb();
+    const contact = await this.get(id);
     invariant(contact, `No contact found for ${id}`);
     const updatedContact = { ...contact, ...values };
-    fakeContacts.records[id] = updatedContact;
+    db.data.records[id] = updatedContact;
+    await db.write();
     return updatedContact;
   },
 
-  destroy(id: string): null {
+  async destroy(id: string): Promise<null> {
-    delete fakeContacts.records[id];
+    const db = await getDb();
+    delete db.data.records[id];
+    await db.write();
     return null;
   },
+
+  // New reset function to restore the initial data
+  async reset(): Promise<void> {
+    const db = await getDb();
+    db.data.records = {};
+    await db.write();
+
+    // Restore initial data
+    const initialContacts = getInitialContacts();
+    for (const contact of initialContacts) {
+      await this.create(contact);
+    }
+  }
 };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -94,10 +153,18 @@ export async function updateContact(id: string, updates: ContactMutation) {
 }
 
 export async function deleteContact(id: string) {
-  fakeContacts.destroy(id);
+  await fakeContacts.destroy(id);
 }
 
-[
+// New function to reset the database to initial state
+export async function resetDatabase() {
+  console.log("RESET DATABASE");
+  await fakeContacts.reset();
+}
+
+// Helper function to get initial contacts data
+function getInitialContacts() {
+  return [
     {
       avatar:
         "https://sessionize.com/image/124e-400o400o2-wHVdAuNaxi8KJrgtN3ZKci.jpg",
@@ -310,12 +377,19 @@ export async function deleteContact(id: string) {
       last: "Jensen",
       twitter: "@jenseng",
     },
-].forEach((contact) => {
+  ].map(contact => ({
-  fakeContacts.create({
     ...contact,
     id: `${contact.first
       .toLowerCase()
       .split(" ")
-      .join("_")}-${contact.last.toLocaleLowerCase()}`,
+      .join("_")}-${contact.last.toLowerCase()}`,
-  });
+  }));
-});
+}
+
+// Initialize with seed data on first load
+(async () => {
+  const db = await getDb();
+  if (Object.keys(db.data.records).length === 0) {
+    await resetDatabase();
+  }
+})();