Reorganize the repo structure (#2503)

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

test/utils/introspection/SupportsInterface.behavior.js

@@ -0,0 +1,88 @@
+const { makeInterfaceId } = require('@openzeppelin/test-helpers');
+
+const { expect } = require('chai');
+
+const INTERFACES = {
+  ERC165: [
+    'supportsInterface(bytes4)',
+  ],
+  ERC721: [
+    'balanceOf(address)',
+    'ownerOf(uint256)',
+    'approve(address,uint256)',
+    'getApproved(uint256)',
+    'setApprovalForAll(address,bool)',
+    'isApprovedForAll(address,address)',
+    'transferFrom(address,address,uint256)',
+    'safeTransferFrom(address,address,uint256)',
+    'safeTransferFrom(address,address,uint256,bytes)',
+  ],
+  ERC721Enumerable: [
+    'totalSupply()',
+    'tokenOfOwnerByIndex(address,uint256)',
+    'tokenByIndex(uint256)',
+  ],
+  ERC721Metadata: [
+    'name()',
+    'symbol()',
+    'tokenURI(uint256)',
+  ],
+  ERC1155: [
+    'balanceOf(address,uint256)',
+    'balanceOfBatch(address[],uint256[])',
+    'setApprovalForAll(address,bool)',
+    'isApprovedForAll(address,address)',
+    'safeTransferFrom(address,address,uint256,uint256,bytes)',
+    'safeBatchTransferFrom(address,address,uint256[],uint256[],bytes)',
+  ],
+  ERC1155Receiver: [
+    'onERC1155Received(address,address,uint256,uint256,bytes)',
+    'onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)',
+  ],
+};
+
+const INTERFACE_IDS = {};
+const FN_SIGNATURES = {};
+for (const k of Object.getOwnPropertyNames(INTERFACES)) {
+  INTERFACE_IDS[k] = makeInterfaceId.ERC165(INTERFACES[k]);
+  for (const fnName of INTERFACES[k]) {
+    // the interface id of a single function is equivalent to its function signature
+    FN_SIGNATURES[fnName] = makeInterfaceId.ERC165([fnName]);
+  }
+}
+
+function shouldSupportInterfaces (interfaces = []) {
+  describe('Contract interface', function () {
+    beforeEach(function () {
+      this.contractUnderTest = this.mock || this.token || this.holder;
+    });
+
+    for (const k of interfaces) {
+      const interfaceId = INTERFACE_IDS[k];
+      describe(k, function () {
+        describe('ERC165\'s supportsInterface(bytes4)', function () {
+          it('uses less than 30k gas [skip-on-coverage]', async function () {
+            expect(await this.contractUnderTest.supportsInterface.estimateGas(interfaceId)).to.be.lte(30000);
+          });
+
+          it('claims support', async function () {
+            expect(await this.contractUnderTest.supportsInterface(interfaceId)).to.equal(true);
+          });
+        });
+
+        for (const fnName of INTERFACES[k]) {
+          const fnSig = FN_SIGNATURES[fnName];
+          describe(fnName, function () {
+            it('has to be implemented', function () {
+              expect(this.contractUnderTest.abi.filter(fn => fn.signature === fnSig).length).to.equal(1);
+            });
+          });
+        }
+      });
+    }
+  });
+}
+
+module.exports = {
+  shouldSupportInterfaces,
+};