Fix .gitignore: stop tracking ignored files

backend/lib/openzeppelin-contracts/test/token/ERC20/extensions/ERC20Capped.behavior.js

@@ -0,0 +1,32 @@
+const { expectRevert } = require('@openzeppelin/test-helpers');
+
+const { expect } = require('chai');
+
+function shouldBehaveLikeERC20Capped(accounts, cap) {
+  describe('capped token', function () {
+    const user = accounts[0];
+
+    it('starts with the correct cap', async function () {
+      expect(await this.token.cap()).to.be.bignumber.equal(cap);
+    });
+
+    it('mints when amount is less than cap', async function () {
+      await this.token.$_mint(user, cap.subn(1));
+      expect(await this.token.totalSupply()).to.be.bignumber.equal(cap.subn(1));
+    });
+
+    it('fails to mint if the amount exceeds the cap', async function () {
+      await this.token.$_mint(user, cap.subn(1));
+      await expectRevert(this.token.$_mint(user, 2), 'ERC20Capped: cap exceeded');
+    });
+
+    it('fails to mint after cap is reached', async function () {
+      await this.token.$_mint(user, cap);
+      await expectRevert(this.token.$_mint(user, 1), 'ERC20Capped: cap exceeded');
+    });
+  });
+}
+
+module.exports = {
+  shouldBehaveLikeERC20Capped,
+};