Merge pull request #3177 from NomicFoundation/relax-eth-storage-at-va…

…lidation Make eth_getStorageAt more permissive
NomicFoundation · Sep 14, 2022 · f7d3843 · f7d3843
2 parents bbccf5c + 10f03fb
commit f7d3843
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Showing 3 changed files with 108 additions and 16 deletions.
diff --git a/.changeset/big-cooks-decide.md b/.changeset/big-cooks-decide.md
@@ -0,0 +1,5 @@
+---
+"hardhat": patch
+---
+
+Make `eth_getStorageAt` more permissive
diff --git a/packages/hardhat-core/src/internal/core/jsonrpc/types/base-types.ts b/packages/hardhat-core/src/internal/core/jsonrpc/types/base-types.ts
@@ -49,23 +49,37 @@ function validateStorageSlot(u: unknown, c: t.Context): t.Validation<bigint> {
     );
   }
 
-  if (u.match(/^0x(?:[0-9a-fA-F]*)*$/) === null) {
-    return t.failure(
-      u,
-      c,
-      `Storage slot argument must be a valid hexadecimal prefixed with "0x", got '${u}'`
-    );
+  if (u === "") {
+    return t.failure(u, c, "Storage slot argument cannot be an empty string");
+  }
+
+  if (u.startsWith("0x")) {
+    if (u.length > 66) {
+      return t.failure(
+        u,
+        c,
+        `Storage slot argument must have a length of at most 66 ("0x" + 32 bytes), but '${u}' has a length of ${u.length}`
+      );
+    }
+  } else {
+    if (u.length > 64) {
+      return t.failure(
+        u,
+        c,
+        `Storage slot argument must have a length of at most 64 (32 bytes), but '${u}' has a length of ${u.length}`
+      );
+    }
   }
 
-  if (u.length !== 66) {
+  if (u.match(/^(0x)?([0-9a-fA-F]){0,64}$/) === null) {
     return t.failure(
       u,
       c,
-      `Storage slot argument must have a length of 66 ("0x" + 32 bytes), but '${u}' has a length of ${u.length}`
+      `Storage slot argument must be a valid hexadecimal, got '${u}'`
     );
   }
 
-  return t.success(BigInt(u));
+  return t.success(u === "0x" ? 0n : BigInt(u.startsWith("0x") ? u : `0x${u}`));
 }
 
 export const rpcAddress = new t.Type<Buffer>(

diff --git a/...s/hardhat-core/test/internal/hardhat-network/provider/modules/eth/methods/getStorageAt.ts b/...s/hardhat-core/test/internal/hardhat-network/provider/modules/eth/methods/getStorageAt.ts
@@ -263,6 +263,69 @@ describe("Eth module", function () {
             );
           });
 
+          it("should accept short hex strings", async function () {
+            const validHexStrings = [
+              "0x",
+              "0x0",
+              "0x00",
+              "0x000",
+              "0x1",
+              "0x01",
+              "0x001",
+              "0xA",
+              "0x0A",
+              "0x00A",
+              "0xb",
+              "0x0b",
+              "0x00b",
+            ];
+
+            for (const storageSlot of validHexStrings) {
+              assert.strictEqual(
+                await this.provider.send("eth_getStorageAt", [
+                  "0x0101010101010101010101010101010101010101",
+                  storageSlot,
+                ]),
+                "0x0000000000000000000000000000000000000000000000000000000000000000"
+              );
+            }
+          });
+
+          it("should accept storage slots without the 0x prefix", async function () {
+            const validHexStrings = [
+              "0",
+              "00",
+              "000",
+              "1",
+              "01",
+              "001",
+              "A",
+              "0A",
+              "00A",
+              "b",
+              "0b",
+              "00b",
+            ];
+
+            for (const storageSlot of validHexStrings) {
+              assert.strictEqual(
+                await this.provider.send("eth_getStorageAt", [
+                  "0x0101010101010101010101010101010101010101",
+                  storageSlot,
+                ]),
+                "0x0000000000000000000000000000000000000000000000000000000000000000"
+              );
+            }
+
+            assert.strictEqual(
+              await this.provider.send("eth_getStorageAt", [
+                "0x0101010101010101010101010101010101010101",
+                "0000000000000000000000000000000000000000000000000000000000000000",
+              ]),
+              "0x0000000000000000000000000000000000000000000000000000000000000000"
+            );
+          });
+
           it("should not accept plain numbers", async function () {
             await assertInvalidArgumentsError(
               this.provider,
@@ -272,21 +335,21 @@ describe("Eth module", function () {
             );
           });
 
-          it("should not accept invalid hex strings", async function () {
+          it("should not accept empty strings", async function () {
             await assertInvalidArgumentsError(
               this.provider,
               "eth_getStorageAt",
-              ["0x0101010101010101010101010101010101010101", "0xABCDEFG"],
-              "Storage slot argument must be a valid hexadecimal prefixed with \"0x\", got '0xABCDEFG'"
+              ["0x0101010101010101010101010101010101010101", ""],
+              "Storage slot argument cannot be an empty string"
             );
           });
 
-          it("should not accept hex strings that are too short", async function () {
+          it("should not accept invalid hex strings", async function () {
             await assertInvalidArgumentsError(
               this.provider,
               "eth_getStorageAt",
-              ["0x0101010101010101010101010101010101010101", "0x0"],
-              `Storage slot argument must have a length of 66 ("0x" + 32 bytes), but '0x0' has a length of 3`
+              ["0x0101010101010101010101010101010101010101", "0xABCDEFG"],
+              "Storage slot argument must be a valid hexadecimal, got '0xABCDEFG'"
             );
           });
 
@@ -298,7 +361,17 @@ describe("Eth module", function () {
                 "0x0101010101010101010101010101010101010101",
                 "0x00000000000000000000000000000000000000000000000000000000000000000",
               ],
-              `Storage slot argument must have a length of 66 ("0x" + 32 bytes), but '0x00000000000000000000000000000000000000000000000000000000000000000' has a length of 67`
+              `Storage slot argument must have a length of at most 66 ("0x" + 32 bytes), but '0x00000000000000000000000000000000000000000000000000000000000000000' has a length of 67`
+            );
+
+            await assertInvalidArgumentsError(
+              this.provider,
+              "eth_getStorageAt",
+              [
+                "0x0101010101010101010101010101010101010101",
+                "00000000000000000000000000000000000000000000000000000000000000000",
+              ],
+              `Storage slot argument must have a length of at most 64 (32 bytes), but '00000000000000000000000000000000000000000000000000000000000000000' has a length of 65`
             );
           });
         });