feat: add test and export encrypt4

src/sdk/encrypt.test.ts

@@ -1,8 +1,10 @@
 import {
+  FheUint4,
   FheUint8,
   FheUint16,
   FheUint32,
   FheUint64,
+  CompactFheUint4List,
   CompactFheUint8List,
   CompactFheUint16List,
   CompactFheUint32List,
@@ -11,7 +13,7 @@ import {
   TfheClientKey,
 } from 'node-tfhe';
 import { createTfheKeypair } from '../tfhe';
-import { encrypt8, encrypt16, encrypt32, encrypt64 } from './encrypt';
+import { encrypt4, encrypt8, encrypt16, encrypt32, encrypt64 } from './encrypt';
 
 describe('encrypt8', () => {
   let clientKey: TfheClientKey;
@@ -23,6 +25,26 @@ describe('encrypt8', () => {
     publicKey = keypair.publicKey;
   });
 
+  it('encrypt/decrypt 0 4bits', async () => {
+    const buffer = encrypt4(0, publicKey);
+    const compactList = CompactFheUint4List.deserialize(buffer);
+    let encryptedList = compactList.expand();
+    encryptedList.forEach((v: FheUint4) => {
+      const decrypted = v.decrypt(clientKey);
+      expect(decrypted).toBe(0);
+    });
+  });
+
+  it('encrypt/decrypt 4bits', async () => {
+    const buffer = encrypt4(7, publicKey);
+    const compactList = CompactFheUint4List.deserialize(buffer);
+    let encryptedList = compactList.expand();
+    encryptedList.forEach((v: FheUint4) => {
+      const decrypted = v.decrypt(clientKey);
+      expect(decrypted).toBe(7);
+    });
+  });
+
   it('encrypt/decrypt 0 8bits', async () => {
     const buffer = encrypt8(0, publicKey);
     const compactList = CompactFheUint8List.deserialize(buffer);

src/sdk/index.ts

@@ -1,6 +1,6 @@
 import { TfheCompactPublicKey } from 'node-tfhe';
 import sodium from 'libsodium-wrappers';
-import { encrypt8, encrypt16, encrypt32, encrypt64 } from './encrypt';
+import { encrypt4, encrypt8, encrypt16, encrypt32, encrypt64 } from './encrypt';
 import {
   EIP712,
   GeneratePublicKeyParams,
@@ -11,6 +11,7 @@ import { fromHexString, isAddress, toHexString } from '../utils';
 import { ContractKeypairs } from './types';
 
 export type FhevmInstance = {
+  encrypt4: (value: number) => Uint8Array;
   encrypt8: (value: number) => Uint8Array;
   encrypt16: (value: number) => Uint8Array;
   encrypt32: (value: number) => Uint8Array;
@@ -107,6 +108,15 @@ export const createInstance = async (
 
   return {
     // Parameters
+    encrypt4(value) {
+      if (value == null) throw new Error('Missing value');
+      if (typeof value !== 'number') throw new Error('Value must be a number');
+      if (!tfheCompactPublicKey)
+        throw new Error(
+          'Your instance has been created without the public blockchain key',
+        );
+      return encrypt4(value, tfheCompactPublicKey);
+    },
     encrypt8(value) {
       if (value == null) throw new Error('Missing value');
       if (typeof value !== 'number') throw new Error('Value must be a number');