Introduce ERC1155 totalSupply() and exists() functions (#2593)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

test/token/ERC1155/extensions/ERC1155Supply.test.js

@@ -0,0 +1,111 @@
+const { BN } = require('@openzeppelin/test-helpers');
+
+const { expect } = require('chai');
+
+const ERC1155SupplyMock = artifacts.require('ERC1155SupplyMock');
+
+contract('ERC1155Supply', function (accounts) {
+  const [ holder ] = accounts;
+
+  const uri = 'https://token.com';
+
+  const firstTokenId = new BN('37');
+  const firstTokenAmount = new BN('42');
+
+  const secondTokenId = new BN('19842');
+  const secondTokenAmount = new BN('23');
+
+  beforeEach(async function () {
+    this.token = await ERC1155SupplyMock.new(uri);
+  });
+
+  context('before mint', function () {
+    it('exist', async function () {
+      expect(await this.token.exists(firstTokenId)).to.be.equal(false);
+    });
+
+    it('totalSupply', async function () {
+      expect(await this.token.totalSupply(firstTokenId)).to.be.bignumber.equal('0');
+    });
+  });
+
+  context('after mint', function () {
+    context('single', function () {
+      beforeEach(async function () {
+        await this.token.mint(holder, firstTokenId, firstTokenAmount, '0x');
+      });
+
+      it('exist', async function () {
+        expect(await this.token.exists(firstTokenId)).to.be.equal(true);
+      });
+
+      it('totalSupply', async function () {
+        expect(await this.token.totalSupply(firstTokenId)).to.be.bignumber.equal(firstTokenAmount);
+      });
+    });
+
+    context('batch', function () {
+      beforeEach(async function () {
+        await this.token.mintBatch(
+          holder,
+          [ firstTokenId, secondTokenId ],
+          [ firstTokenAmount, secondTokenAmount ],
+          '0x',
+        );
+      });
+
+      it('exist', async function () {
+        expect(await this.token.exists(firstTokenId)).to.be.equal(true);
+        expect(await this.token.exists(secondTokenId)).to.be.equal(true);
+      });
+
+      it('totalSupply', async function () {
+        expect(await this.token.totalSupply(firstTokenId)).to.be.bignumber.equal(firstTokenAmount);
+        expect(await this.token.totalSupply(secondTokenId)).to.be.bignumber.equal(secondTokenAmount);
+      });
+    });
+  });
+
+  context('after burn', function () {
+    context('single', function () {
+      beforeEach(async function () {
+        await this.token.mint(holder, firstTokenId, firstTokenAmount, '0x');
+        await this.token.burn(holder, firstTokenId, firstTokenAmount);
+      });
+
+      it('exist', async function () {
+        expect(await this.token.exists(firstTokenId)).to.be.equal(false);
+      });
+
+      it('totalSupply', async function () {
+        expect(await this.token.totalSupply(firstTokenId)).to.be.bignumber.equal('0');
+      });
+    });
+
+    context('batch', function () {
+      beforeEach(async function () {
+        await this.token.mintBatch(
+          holder,
+          [ firstTokenId, secondTokenId ],
+          [ firstTokenAmount, secondTokenAmount ],
+          '0x',
+        );
+        await this.token.burnBatch(
+          holder,
+          [ firstTokenId, secondTokenId ],
+          [ firstTokenAmount, secondTokenAmount ],
+        );
+      });
+
+      it('exist', async function () {
+        expect(await this.token.exists(firstTokenId)).to.be.equal(false);
+        expect(await this.token.exists(secondTokenId)).to.be.equal(false);
+      });
+
+      it('totalSupply', async function () {
+        expect(await this.token.totalSupply(firstTokenId)).to.be.bignumber.equal('0');
+        expect(await this.token.totalSupply(secondTokenId)).to.be.bignumber.equal('0');
+      });
+    });
+  });
+});