feat(rpc): add rpc connection

.github/workflows/foundry-storage-check.yml

@@ -28,6 +28,6 @@ jobs:
           version: nightly
 
       - name: Check storage layout
-        uses: Rubilmax/foundry-storage-check@v2.1
+        uses: Rubilmax/foundry-storage-check@v3
         with:
           contract: contracts/Example.sol:Example

README.md

@@ -4,17 +4,11 @@
 
 ## Live Example
 
-Checkout [PR #21](/pulls/21) for a live example:
+Check out [PR #21](/pulls/21) for a live example:
 
 - Action is ran on [contracts/Example.sol:Example](./contracts/Example.sol)
 - Warnings & errors appear on the [Pull Request changes](https://github.com/Rubilmax/foundry-storage-check/pull/21/files)
 
-## How it works
-
-Everytime somebody opens a Pull Request, the action runs [Foundry](https://github.com/foundry-rs/foundry) `forge` to generate the storage layout of the Smart Contract you want to check.
-
-Once generated, the action will fetch the comparative storage layout stored as an artifact from previous runs; parse & compare them, pinning warnings and errors on the Pull Request.
-
 ## Getting started
 
 ### Automatically generate & compare to the previous storage layout on every PR
@@ -52,15 +46,35 @@ jobs:
           version: nightly
 
       - name: Check storage layout
-        uses: Rubilmax/foundry-storage-check@v2.1
+        uses: Rubilmax/foundry-storage-check@v3
         with:
           contract: src/Contract.sol:Contract
+          # settings below are optional, but allows to check whether the added storage slots are empty on the deployed contract
+          rpcUrl: wss://eth-mainnet.g.alchemy.com/v2/<YOUR_ALCHEMY_KEY> # the RPC url to use to query the deployed contract's storage slots
+          address: 0x0000000000000000000000000000000000000000 # the address at which the contract check is deployed
+          failOnRemoval: true # fail the CI when removing storage slots (default: false)
 ```
 
 > :information_source: **An error will appear at first run!**<br/>
 > 🔴 <em>**Error:** No workflow run found with an artifact named "..."</em><br/>
 > As the action is expecting a comparative file stored on the base branch and cannot find it (because the action never ran on the target branch and thus has never uploaded any storage layout)
 
+---
+
+## How it works
+
+Everytime somebody opens a Pull Request, the action runs [Foundry](https://github.com/foundry-rs/foundry) `forge` to generate the storage layout of the Smart Contract you want to check.
+
+Once generated, the action will fetch the comparative storage layout stored as an artifact from previous runs and compare them, to perform a series of checks at each storage byte, and raise a notice accordingly:
+
+- Variable changed: `error`
+- Type definition changed: `error`
+- Type definition removed: `warning`
+- Different variable naming: `warning`
+- Variable removed (optional): `error`
+
+---
+
 ## Options
 
 ### `contract` _{string}_
@@ -69,6 +83,20 @@ The path and name of the contract of which to inspect storage layout (e.g. src/C
 
 _Required_
 
+### `address` _{string}_
+
+The address at which the contract is deployed on the EVM-compatible chain queried via `rpcUrl`.
+
+### `rpcUrl` _{string}_
+
+The HTTP/WS url used to query the EVM-compatible chain for storage slots to check for clashing.
+
+### `failOnRemoval` _{string}_
+
+Whether to fail the CI when removing a storage slot (to only allow added or renamed storage slots).
+
+_Defaults to: `false`_
+
 ### `base` _{string}_
 
 The gas diff reference branch name, used to fetch the previous gas report to compare the freshly generated gas report to.

action.yml

@@ -9,6 +9,16 @@ inputs:
   contract:
     description: The path and name of the contract of which to inspect storage layout (e.g. src/Contract.sol:Contract).
     required: true
+  address:
+    description: The address at which the contract is deployed on the EVM-compatible chain queried via rpcUrl.
+    required: false
+  rpcUrl:
+    description: The HTTP/WS url used to query the EVM-compatible chain for storage slots to check for clashing.
+    required: false
+  failOnRemoval:
+    description: Whether to fail the CI when removing a storage slot (to only allow added or renamed storage slots).
+    required: false
+    default: false
   token:
     description: The repository's github token.
     default: ${{ github.token }}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "foundry-storage-check",
-  "version": "2.1.0",
+  "version": "3.0.0",
   "description": "Github Action checking the storage layout diff from Foundry storage layout reports",
   "author": {
     "name": "Romain (Rubilmax) Milon",
@@ -43,9 +43,11 @@
     "@actions/artifact": "^1.1.0",
     "@actions/core": "^1.10.0",
     "@actions/github": "^5.1.1",
+    "@ethersproject/providers": "^5.7.2",
+    "@ethersproject/solidity": "^5.7.0",
     "@octokit/core": "^4.1.0",
     "@solidity-parser/parser": "^0.14.5",
-    "keccak256": "^1.0.6",
+    "js-sha3": "^0.8.0",
     "lodash": "^4.17.21"
   },
   "devDependencies": {

src/check.ts

@@ -1,18 +1,22 @@
-import keccak256 from "keccak256";
 import _isEqual from "lodash/isEqual";
 import _range from "lodash/range";
+import _sortBy from "lodash/sortBy";
 import _uniqWith from "lodash/uniqWith";
 
+import { Provider } from "@ethersproject/providers";
+import { keccak256 } from "@ethersproject/solidity";
+
 import {
+  StorageLayoutDiffAdded,
   StorageLayoutDiff,
   StorageLayoutDiffType,
   StorageLayoutReportExact,
   StorageVariableDetails,
   StorageVariableExact,
+  StorageLayoutDiffAddedNonZeroSlot,
 } from "./types";
 
 export const STORAGE_WORD_SIZE = 32n;
-export const ZERO_BYTE = "".padStart(64, "0");
 
 interface StorageBytesMapping {
   [byte: string]: StorageVariableDetails;
@@ -29,7 +33,7 @@ const getStorageVariableBytesMapping = (
   let example = {};
   switch (varType.encoding) {
     case "dynamic_array":
-      slot = BigInt("0x" + keccak256("0x" + variable.slot.toString(16)).toString("hex")); // slot of the element at index 0
+      slot = BigInt(keccak256(["uint256"], [variable.slot])); // slot of the element at index 0
       example = getStorageVariableBytesMapping(
         layout,
         {
@@ -39,13 +43,11 @@ const getStorageVariableBytesMapping = (
           type: varType.base!,
           label: variable.label.replace("[]", "[0]"),
         },
-        startByte + slot * STORAGE_WORD_SIZE
+        slot * STORAGE_WORD_SIZE
       );
       break;
     case "mapping":
-      slot = BigInt(
-        "0x" + keccak256("0x" + ZERO_BYTE + variable.slot.toString(16)).toString("hex")
-      ); // slot of the element at key 0
+      slot = BigInt(keccak256(["uint256", "uint256"], [0, variable.slot])); // slot of the element at key 0
       example = getStorageVariableBytesMapping(
         layout,
         {
@@ -55,7 +57,7 @@ const getStorageVariableBytesMapping = (
           type: varType.value!,
           label: `${variable.label}[0]`,
         },
-        startByte + slot * STORAGE_WORD_SIZE
+        slot * STORAGE_WORD_SIZE
       );
       break;
     default:
@@ -65,7 +67,7 @@ const getStorageVariableBytesMapping = (
   const details: StorageVariableDetails = {
     ...variable,
     fullLabel: variable.parent
-      ? `(${variable.parent.typeLabel})${variable.parent.label}.${variable.label}`
+      ? `(${variable.parent.typeLabel} ${variable.parent.label}).${variable.label}`
       : variable.label,
     typeLabel: varType.label.replace(/struct /, ""),
     startByte,
@@ -112,11 +114,17 @@ const getStorageBytesMapping = (layout: StorageLayoutReportExact): StorageBytesM
     {}
   );
 
-export const checkLayouts = (
+export const checkLayouts = async (
   srcLayout: StorageLayoutReportExact,
-  cmpLayout: StorageLayoutReportExact
-): StorageLayoutDiff[] => {
+  cmpLayout: StorageLayoutReportExact,
+  {
+    address,
+    provider,
+    checkRemovals,
+  }: { address?: string; provider?: Provider; checkRemovals?: boolean } = {}
+): Promise<StorageLayoutDiff[]> => {
   const diffs: StorageLayoutDiff[] = [];
+  const added: StorageLayoutDiffAdded[] = [];
 
   const srcMapping = getStorageBytesMapping(srcLayout);
   const cmpMapping = getStorageBytesMapping(cmpLayout);
@@ -125,7 +133,21 @@ export const checkLayouts = (
     const srcSlotVar = srcMapping[byte];
     const cmpSlotVar = cmpMapping[byte];
 
-    if (!srcSlotVar) continue; // source byte was unused
+    const byteIndex = BigInt(byte);
+    const location = {
+      slot: byteIndex / STORAGE_WORD_SIZE,
+      offset: byteIndex % STORAGE_WORD_SIZE,
+    };
+
+    if (!srcSlotVar) {
+      added.push({
+        location,
+        cmp: cmpSlotVar,
+      });
+
+      continue; // source byte was unused
+    }
+
     if (
       cmpSlotVar.type === srcSlotVar.type &&
       cmpSlotVar.fullLabel === srcSlotVar.fullLabel &&
@@ -134,18 +156,30 @@ export const checkLayouts = (
       cmpSlotVar.startByte === srcSlotVar.startByte
     )
       continue; // variable did not change
-    if (srcSlotVar.label === "__gap" || cmpSlotVar.label === "__gap") continue; // source byte was part of a gap slot or is replaced with a gap slot
+
+    if (srcSlotVar.label === "__gap" || cmpSlotVar.label === "__gap") {
+      added.push({
+        location,
+        cmp: cmpSlotVar,
+      });
+
+      continue; // source byte was part of a gap slot or is replaced with a gap slot
+    }
 
     if (cmpSlotVar.fullLabel !== srcSlotVar.fullLabel) {
-      if (cmpSlotVar.fullLabel.startsWith(`(${srcSlotVar.typeLabel})${srcSlotVar.label}`)) continue; // variable is a member of source struct, in empty bytes
+      if (cmpSlotVar.fullLabel.startsWith(`(${srcSlotVar.typeLabel} ${srcSlotVar.label})`)) {
+        added.push({
+          location,
+          cmp: cmpSlotVar,
+        });
+
+        continue; // variable is a member of source struct, in empty bytes
+      }
 
       if (cmpSlotVar.type === srcSlotVar.type) {
         if (cmpSlotVar.label !== srcSlotVar.label)
           diffs.push({
-            location: {
-              slot: srcSlotVar.slot,
-              offset: srcSlotVar.offset,
-            },
+            location,
             type: StorageLayoutDiffType.LABEL,
             src: srcSlotVar,
             cmp: cmpSlotVar,
@@ -155,10 +189,7 @@ export const checkLayouts = (
       }
 
       diffs.push({
-        location: {
-          slot: srcSlotVar.slot,
-          offset: srcSlotVar.offset,
-        },
+        location,
         type: StorageLayoutDiffType.VARIABLE,
         src: srcSlotVar,
         cmp: cmpSlotVar,
@@ -202,10 +233,7 @@ export const checkLayouts = (
       }
 
       diffs.push({
-        location: {
-          slot: srcSlotVar.slot,
-          offset: srcSlotVar.offset,
-        },
+        location,
         type: StorageLayoutDiffType.VARIABLE_TYPE,
         src: srcSlotVar,
         cmp: cmpSlotVar,
@@ -215,5 +243,64 @@ export const checkLayouts = (
     }
   }
 
-  return _uniqWith(diffs, _isEqual);
+  if (checkRemovals) {
+    for (const byte of Object.keys(srcMapping)) {
+      const srcSlotVar = srcMapping[byte];
+      const cmpSlotVar = cmpMapping[byte];
+
+      const byteIndex = BigInt(byte);
+      const location = {
+        slot: byteIndex / STORAGE_WORD_SIZE,
+        offset: byteIndex % STORAGE_WORD_SIZE,
+      };
+
+      if (!cmpSlotVar)
+        diffs.push({
+          location,
+          type: StorageLayoutDiffType.VARIABLE_REMOVED,
+          src: srcSlotVar,
+        });
+    }
+  }
+
+  return _uniqWith(
+    _sortBy(diffs, ["location.slot", "location.offset"]), // make sure it's ordered by storage byte order
+    ({ location: location1, ...diff1 }, { location: location2, ...diff2 }) => _isEqual(diff1, diff2) // only keep first byte diff of a variable, which corresponds to the start byte
+  ).concat(address && provider ? await checkAddedStorageSlots(added, address, provider) : []);
+};
+
+const checkAddedStorageSlots = async (
+  added: StorageLayoutDiffAdded[],
+  address: string,
+  provider: Provider
+): Promise<StorageLayoutDiffAddedNonZeroSlot[]> => {
+  const storage: { [slot: string]: string } = {};
+  const diffs: StorageLayoutDiffAddedNonZeroSlot[] = [];
+
+  for (const diff of _sortBy(added, ["location.slot", "location.offset"])) {
+    const slot = diff.location.slot.toString();
+
+    const memoized = storage[slot];
+    let value = memoized ?? (await provider.getStorageAt(address, slot));
+    if (!memoized) storage[slot] = value;
+
+    const byteIndex = value.length - Number((diff.location.offset + 1n) * 2n);
+    value = value.substring(byteIndex, byteIndex + 2);
+
+    if (value === "00") continue;
+
+    diffs.push({
+      ...diff,
+      type: StorageLayoutDiffType.NON_ZERO_ADDED_SLOT,
+      value,
+    });
+  }
+
+  return _uniqWith(
+    diffs,
+    (
+      { location: location1, value: value1, ...diff1 },
+      { location: location2, value: value2, ...diff2 }
+    ) => _isEqual(diff1, diff2) // only keep first byte diff of a variable, which corresponds to the start byte
+  );
 };