added example how to work with BigInt (js)

collections-js/sandbox-test/main.ava.js

@@ -32,6 +32,19 @@ test.afterEach.always(async (t) => {
   });
 });
 
+test('testing bigint methods', async (t) => {
+  const { root, contract } = t.context.accounts;
+  const newValue = '1';
+
+  let currentValue = await contract.view('get_big_int', {});
+  t.assert(currentValue === '0', "Incorrect big int");
+
+  await root.call(contract, 'set_big_int', { value: newValue });
+
+  currentValue = await contract.view('get_big_int', {});
+  t.assert(currentValue === currentValue, "Incorrect big int");
+});
+
 test('testing string methods', async (t) => {
   const { root, contract } = t.context.accounts;
   const newGreeting = 'Hi';

collections-js/src/contract.ts

@@ -13,6 +13,7 @@ class Storage {
   };
 
   greeting: string = 'Hello';
+  big_int: BigInt = BigInt(0);
   vector: Vector<number> = new Vector<number>('uid-1');
   lookup_set: LookupSet<number> = new LookupSet<number>('uid-2');
   unordered_set: UnorderedSet<number> = new UnorderedSet<number>('uid-3');
@@ -31,6 +32,17 @@ class Storage {
     this.greeting = greeting;
   }
 
+  @view({}) // This method is read-only and can be called for free
+  get_big_int(): string {
+    return this.big_int as unknown as string; // Because of serializing process it actually returns BigInt as string for view methods
+  }
+
+  @call({}) // This method changes the state, for which it cost gas
+  set_big_int({ value }: { value: string }): void {
+    near.log(`Saving big int value: ${value}`);
+    this.big_int = BigInt(value);
+  }
+
   // Vector
   @call({})
   push_vector({ value }: { value: number }) {