Fix .gitignore: stop tracking ignored files

backend/lib/openzeppelin-contracts/test/utils/introspection/ERC165Storage.test.js

@@ -0,0 +1,23 @@
+const { expectRevert } = require('@openzeppelin/test-helpers');
+
+const { shouldSupportInterfaces } = require('./SupportsInterface.behavior');
+
+const ERC165Storage = artifacts.require('$ERC165Storage');
+
+contract('ERC165Storage', function () {
+  beforeEach(async function () {
+    this.mock = await ERC165Storage.new();
+  });
+
+  it('register interface', async function () {
+    expect(await this.mock.supportsInterface('0x00000001')).to.be.equal(false);
+    await this.mock.$_registerInterface('0x00000001');
+    expect(await this.mock.supportsInterface('0x00000001')).to.be.equal(true);
+  });
+
+  it('does not allow 0xffffffff', async function () {
+    await expectRevert(this.mock.$_registerInterface('0xffffffff'), 'ERC165: invalid interface id');
+  });
+
+  shouldSupportInterfaces(['ERC165']);
+});