Support EIP-712 cheatcodes in Solidity Test

.changeset/clever-foxes-jump.md

@@ -0,0 +1,6 @@
+---
+# docs: https://github.com/NomicFoundation/hardhat-website/pull/260
+"@nomicfoundation/hardhat-errors": patch
+---
+
+Add error descriptor for duplicate EIP-712 struct names surfaced by the Solidity Test cheatcodes.

.changeset/good-islands-hide.md

@@ -0,0 +1,6 @@
+---
+# docs: https://github.com/NomicFoundation/hardhat-website/pull/260
+"hardhat": patch
+---
+
+Support EIP-712 cheatcodes in Solidity Test.

packages/hardhat-errors/src/descriptors.ts

@@ -1278,6 +1278,16 @@ Double-check the paths you are providing to the \`test solidity\` task.`,
         websiteDescription:
           "Two distinct snapshot group names sanitize to the same on-disk filename. Rename one of the groups in your Solidity tests so they produce different filenames.",
       },
+      EIP712_DUPLICATE_STRUCT_NAME: {
+        number: 818,
+        messageTemplate: `Two different EIP-712 struct definitions named "{name}" were found:
+- {firstSource}
+- {secondSource}
+
+EIP-712 cheatcodes resolve types by name, so each struct name must have a single canonical definition. Rename one of the structs, or scope your \`test.solidity.eip712Types.include\` / \`exclude\` globs in \`hardhat.config.ts\` to only one of them.`,
+        websiteTitle: "Duplicate EIP-712 struct name",
+        websiteDescription: `Two struct definitions with the same name had different members. Type-name lookups via \`vm.eip712HashType\` and \`vm.eip712HashStruct\` would be ambiguous.`,
+      },
     },
     SOLIDITY: {
       PROJECT_ROOT_RESOLUTION_ERROR: {

packages/hardhat/src/internal/builtin-plugins/solidity-test/config.ts

@@ -89,6 +89,12 @@ const solidityTestUserConfigType = z.object({
       shrinkRunLimit: z.number().optional(),
     })
     .optional(),
+  eip712Types: z
+    .object({
+      include: z.array(z.string()).optional(),
+      exclude: z.array(z.string()).optional(),
+    })
+    .optional(),
 });
 
 const userConfigType = z.object({
@@ -169,6 +175,9 @@ export async function resolveSolidityTestUserConfig(
     ...userConfig.test?.solidity,
     fuzz: resolveFuzzConfig(userConfig.test?.solidity?.fuzz),
     forking: resolvedForking,
+    eip712Types: resolveEip712TypesConfig(
+      userConfig.test?.solidity?.eip712Types,
+    ),
   };
 
   return {
@@ -195,3 +204,12 @@ export function resolveFuzzConfig(
     seed: fuzzUserConfig.seed ?? DEFAULT_FUZZ_SEED,
   };
 }
+
+export function resolveEip712TypesConfig(
+  eip712TypesUserConfig: SolidityTestUserConfig["eip712Types"] = {},
+): SolidityTestConfig["eip712Types"] {
+  return {
+    include: eip712TypesUserConfig.include ?? [],
+    exclude: eip712TypesUserConfig.exclude ?? [],
+  };
+}

packages/hardhat/src/internal/builtin-plugins/solidity-test/eip712/ast-walker.ts

@@ -0,0 +1,324 @@
+import { isObject } from "@nomicfoundation/hardhat-utils/lang";
+
+/**
+ * A single field of a Solidity struct
+ */
+export interface StructMember {
+  name: string;
+  /**
+   * EIP-712 type string, or `undefined` if the type can't be encoded (e.g. mappings).
+   */
+  type: string | undefined;
+}
+
+/**
+ * A Solidity struct extracted from a source AST (Abstract Syntax Tree).
+ */
+export interface CollectedStruct {
+  name: string;
+  members: StructMember[];
+  /**
+   * Project-relative source path. Used for diagnostics only.
+   */
+  sourcePath: string;
+}
+
+/**
+ * A user-defined value type (`type Foo is bytes32;`) resolves to its
+ * underlying elementary type for EIP-712 encoding.
+ * The map is keyed by the user-defined value type definition's solc node id,
+ * which is what `referencedDeclaration` on a `UserDefinedTypeName` reference
+ * points to.
+ */
+export type UserDefinedValueTypeIndex = Map<number, Record<string, unknown>>;
+
+/**
+ * Walks every AST in the build and indexes every `UserDefinedValueTypeDefinition`
+ * by its node `id`, mapping to its `underlyingType` (an `ElementaryTypeName`).
+ *
+ * User-defined value types can sit at file scope or inside a contract, and a
+ * struct in one source may reference a user-defined value type defined in
+ * another, so this must run across every AST in the build — not just the ones
+ * matched by the user's include globs.
+ */
+export function buildUserDefinedValueTypeIndex(
+  asts: unknown[],
+): UserDefinedValueTypeIndex {
+  const index: UserDefinedValueTypeIndex = new Map();
+
+  for (const ast of asts) {
+    if (!isObject(ast) || ast.nodeType !== "SourceUnit") {
+      continue;
+    }
+
+    const topLevelNodes: unknown[] = Array.isArray(ast.nodes) ? ast.nodes : [];
+    for (const node of topLevelNodes) {
+      if (!isObject(node)) {
+        continue;
+      }
+
+      if (node.nodeType === "UserDefinedValueTypeDefinition") {
+        recordUserDefinedValueType(node, index);
+      } else if (node.nodeType === "ContractDefinition") {
+        const members: unknown[] = Array.isArray(node.nodes) ? node.nodes : [];
+        for (const member of members) {
+          if (
+            isObject(member) &&
+            member.nodeType === "UserDefinedValueTypeDefinition"
+          ) {
+            recordUserDefinedValueType(member, index);
+          }
+        }
+      }
+    }
+  }
+
+  return index;
+}
+
+function recordUserDefinedValueType(
+  node: Record<string, unknown>,
+  index: UserDefinedValueTypeIndex,
+): void {
+  if (
+    typeof node.id === "number" &&
+    isObject(node.underlyingType) &&
+    node.underlyingType.nodeType === "ElementaryTypeName"
+  ) {
+    index.set(node.id, node.underlyingType);
+  }
+}
+
+/**
+ * Returns every struct definition reachable from a solc source AST (Abstract Syntax Tree),
+ * including structs nested inside contracts.
+ */
+export function extractStructsFromAst(
+  ast: unknown,
+  sourcePath: string,
+  userDefinedValueTypeI: UserDefinedValueTypeIndex = new Map(),
+): CollectedStruct[] {
+  if (!isObject(ast) || ast.nodeType !== "SourceUnit") {
+    return [];
+  }
+
+  const results: CollectedStruct[] = [];
+  const topLevelNodes: unknown[] = Array.isArray(ast.nodes) ? ast.nodes : [];
+
+  for (const node of topLevelNodes) {
+    if (!isObject(node)) {
+      continue;
+    }
+
+    if (node.nodeType === "StructDefinition") {
+      const collected = collectStruct(node, sourcePath, userDefinedValueTypeI);
+      if (collected !== undefined) {
+        results.push(collected);
+      }
+    } else if (node.nodeType === "ContractDefinition") {
+      const members: unknown[] = Array.isArray(node.nodes) ? node.nodes : [];
+      for (const member of members) {
+        if (isObject(member) && member.nodeType === "StructDefinition") {
+          const collected = collectStruct(
+            member,
+            sourcePath,
+            userDefinedValueTypeI,
+          );
+          if (collected !== undefined) {
+            results.push(collected);
+          }
+        }
+      }
+    }
+  }
+
+  return results;
+}
+
+function collectStruct(
+  node: Record<string, unknown>,
+  sourcePath: string,
+  userDefinedValueTypeI: UserDefinedValueTypeIndex,
+): CollectedStruct | undefined {
+  if (typeof node.name !== "string") {
+    return undefined;
+  }
+
+  const memberNodes: unknown[] = Array.isArray(node.members)
+    ? node.members
+    : [];
+  const members: StructMember[] = [];
+
+  for (const memberNode of memberNodes) {
+    if (
+      !isObject(memberNode) ||
+      memberNode.nodeType !== "VariableDeclaration"
+    ) {
+      continue;
+    }
+
+    if (typeof memberNode.name !== "string") {
+      continue;
+    }
+
+    members.push({
+      name: memberNode.name,
+      type: encodeMemberType(memberNode.typeName, userDefinedValueTypeI),
+    });
+  }
+
+  return {
+    name: node.name,
+    members,
+    sourcePath,
+  };
+}
+
+/**
+ * Converts a solc `typeName` AST node into its EIP-712 type string, following
+ * the same conventions as `forge bind-json`:
+ *
+ *   - elementary types pass through (`address`, `uint256`, `string`, ...)
+ *   - enums                  → `uint8`
+ *   - contracts / interfaces → `address`
+ *   - structs                → bare name (`Wallet.Person` → `Person`)
+ *   - user-defined value types → underlying elementary type (`type Foo is bytes32` → `bytes32`)
+ *   - arrays                 → `T[]` (dynamic) or `T[N]` (fixed)
+ *   - mappings / functions   → `undefined` (not EIP-712 encodable)
+ */
+export function encodeMemberType(
+  typeName: unknown,
+  userDefinedValueTypeI: UserDefinedValueTypeIndex = new Map(),
+): string | undefined {
+  if (!isObject(typeName)) {
+    return undefined;
+  }
+
+  switch (typeName.nodeType) {
+    case "ElementaryTypeName": {
+      // Prefer `typeDescriptions.typeString` over `name`: solc emits the
+      // unresolved alias in `name` (`uint`, `int`, `byte`), but the canonical
+      // EIP-712 type is in `typeString` (`uint256`, `int256`, `bytes1`).
+      // `address payable` is the exception — `typeString` is `"address payable"`
+      // while the canonical EIP-712 type is just `address`.
+      const desc = isObject(typeName.typeDescriptions)
+        ? typeName.typeDescriptions
+        : undefined;
+      const typeString =
+        typeof desc?.typeString === "string" ? desc.typeString : undefined;
+      if (typeString !== undefined) {
+        return typeString.endsWith(" payable")
+          ? typeString.slice(0, -" payable".length)
+          : typeString;
+      }
+
+      return typeof typeName.name === "string" ? typeName.name : undefined;
+    }
+
+    case "UserDefinedTypeName": {
+      // `typeDescriptions.typeString` is the only reliable way to tell what
+      // kind of user-defined type this is — e.g. "struct Foo", "enum Bar",
+      // "contract Token". The AST node itself doesn't say. Note that solc
+      // emits the "contract " prefix for interface references as well.
+      const desc = isObject(typeName.typeDescriptions)
+        ? typeName.typeDescriptions
+        : undefined;
+      const typeString =
+        typeof desc?.typeString === "string" ? desc.typeString : "";
+
+      if (typeString.startsWith("enum ")) {
+        return "uint8";
+      }
+
+      if (typeString.startsWith("contract ")) {
+        return "address";
+      }
+
+      if (typeString.startsWith("struct ")) {
+        // EIP-712 references structs by their bare name, so strip both the
+        // "struct " prefix, any storage-location suffix solc may append
+        // ("memory", "storage", ...), and any qualifier ("Wallet.Person").
+        const remainder = typeString.slice("struct ".length).trim();
+        const namePart = remainder.split(/\s+/)[0];
+        const segments = namePart.split(".");
+        return segments[segments.length - 1];
+      }
+
+      // User-defined value types (`type Foo is bytes32;`, solc 0.8.8+).
+      // Resolve via `referencedDeclaration` against the build-wide
+      // user-defined value type index
+      // and recurse on the underlying elementary type — matching forge's
+      // `Resolver::resolve_type` so `Foo h` encodes as `bytes32 h`, not `Foo h`.
+      const refId =
+        typeof typeName.referencedDeclaration === "number"
+          ? typeName.referencedDeclaration
+          : isObject(typeName.pathNode) &&
+              typeof typeName.pathNode.referencedDeclaration === "number"
+            ? typeName.pathNode.referencedDeclaration
+            : undefined;
+
+      if (refId !== undefined) {
+        const underlying = userDefinedValueTypeI.get(refId);
+        if (underlying !== undefined) {
+          return encodeMemberType(underlying, userDefinedValueTypeI);
+        }
+      }
+
+      // Fallback when the reference can't be resolved (missing
+      // `referencedDeclaration`, or its definition wasn't in the build).
+      // Emitting the name lets the downstream encoder produce a clear error
+      // rather than failing silently here.
+      if (typeof typeName.name === "string") {
+        return typeName.name;
+      }
+
+      if (
+        isObject(typeName.pathNode) &&
+        typeof typeName.pathNode.name === "string"
+      ) {
+        const segments = typeName.pathNode.name.split(".");
+        return segments[segments.length - 1];
+      }
+
+      return undefined;
+    }
+
+    case "ArrayTypeName": {
+      const base = encodeMemberType(typeName.baseType, userDefinedValueTypeI);
+      if (base === undefined) {
+        return undefined;
+      }
+
+      // solc omits `length` entirely for dynamic arrays; it isn't emitted as `null`.
+      const length = typeName.length;
+      if (length === null || length === undefined) {
+        return `${base}[]`;
+      }
+
+      // Always read from typeString: `Literal.value` preserves source text
+      // (`0x100`, `1_000`) but typeString canonicalizes to decimal.
+      const desc = isObject(typeName.typeDescriptions)
+        ? typeName.typeDescriptions
+        : undefined;
+      const typeString =
+        typeof desc?.typeString === "string" ? desc.typeString : "";
+      const match = /\[(\d+)\]$/.exec(typeString);
+
+      if (match !== null) {
+        return `${base}[${match[1]}]`;
+      }
+
+      return undefined;
+    }
+
+    case "Mapping":
+      return undefined;
+
+    case "FunctionTypeName":
+      // EIP-712 can't encode function types.
+      return undefined;
+
+    default:
+      return undefined;
+  }
+}