Adds more documentation for contract proxying

test/contracts/src/ProxyForContractsDemo.sol

@@ -30,6 +30,11 @@ interface IProxy{
     ) external payable;
 }
 
+// This contract adds Alith (0xf24....) as proxy to itself when it gets deployed.
+// The purpose is to trigger a proxy creation BEFORE the contract code is stored.
+// It bypasses the restriction of "no proxy for smart contract" but cannot be exploited
+// because runtimes block the execution of a proxy if the proxied account contains code
+// see https://github.com/moonbeam-foundation/moonbeam/pull/2533/files#diff-95857a497fb7c3739b385c704d94c0f41293c05703b539cb139093f78e0a4cfbR1122
 contract ProxyForContractsDemo {
 
     address immutable PROXY_ADDRESS = 0x000000000000000000000000000000000000080b;

test/suites/dev/moonbase/test-proxy/test-proxy-for-contracts.ts

@@ -19,6 +19,7 @@ describeSuite({
       contractAddress = deployedAddr;
     });
 
+    // See ProxyForContractsDemo.sol for more explanation
     it({
       id: `T01`,
       title: `Proxy Call to Smart Contract account should fail`,
@@ -37,5 +38,16 @@ describeSuite({
         ).rejects.toThrow("Invalid Transaction: Transaction call is not expected");
       },
     });
+
+    it({
+      id: `T02`,
+      title: `Adding a proxy to an existing contract should succeed`,
+      test: async function () {
+        const { result } = await context.createBlock(
+          context.polkadotJs().tx.proxy.addProxy(contractAddress, "Any", 0)
+        )
+        expect(result?.successful).to.be.true;
+      },
+    });
   },
 });