Merge pull request #6574 from NomicFoundation/viem-matchers-first-iteration

Viem matchers first iteration

Author: ChristopherDedominici

.changeset/config.json

@@ -32,14 +32,11 @@
       "@nomicfoundation/hardhat-utils",
       "@nomicfoundation/hardhat-toolbox-mocha-ethers",
       "@nomicfoundation/hardhat-viem",
+      "@nomicfoundation/hardhat-viem-matchers",
       "@nomicfoundation/hardhat-zod-utils"
     ],
-    [
-      "@nomicfoundation/hardhat-toolbox-viem"
-    ],
-    [
-      "@nomicfoundation/hardhat-ethers"
-    ]
+    ["@nomicfoundation/hardhat-toolbox-viem"],
+    ["@nomicfoundation/hardhat-ethers"]
   ],
   "___experimentalUnsafeOptions_WILL_CHANGE_IN_PATCH": {
     "onlyUpdatePeerDependentsWhenOutOfRange": true

.changeset/pre.json

@@ -22,6 +22,7 @@
     "@nomicfoundation/hardhat-utils": "2.0.0",
     "@nomicfoundation/hardhat-toolbox-mocha-ethers": "2.0.0",
     "@nomicfoundation/hardhat-viem": "2.0.6",
+    "@nomicfoundation/hardhat-viem-matchers": "2.0.0",
     "@nomicfoundation/hardhat-zod-utils": "2.0.0",
     "@nomicfoundation/template-package": "3.0.0",
     "template-empty-javascript": "0.0.1",

pnpm-lock.yaml

@@ -0,0 +1,14 @@
+# Node modules
+/node_modules
+
+# Compilation output
+/dist
+
+# pnpm deploy output
+/bundle
+
+# test coverage output
+coverage
+
+# all the tmp folders in the fixture projects
+/test/fixture-projects/tmp/

v-next/hardhat-viem-matchers/.gitignore

@@ -0,0 +1,6 @@
+/node_modules
+/dist
+/coverage
+CHANGELOG.md
+/test/fixture-projects/*/artifacts
+/test/fixture-projects/*/cache

v-next/hardhat-viem-matchers/.prettierignore

@@ -0,0 +1,9 @@
+MIT License
+
+Copyright (c) 2025 Nomic Foundation
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

v-next/hardhat-viem-matchers/LICENSE

@@ -0,0 +1 @@
+# TODO

v-next/hardhat-viem-matchers/README.md

@@ -0,0 +1,3 @@
+import { createConfig } from "../config/eslint.config.js";
+
+export default createConfig(import.meta.filename);

v-next/hardhat-viem-matchers/eslint.config.js

@@ -0,0 +1,71 @@
+{
+  "name": "@nomicfoundation/hardhat-viem-matchers",
+  "version": "3.0.0-next.11",
+  "description": "A Hardhat plugin that adds matchers for Viem",
+  "homepage": "https://github.com/nomicfoundation/hardhat/tree/v-next/v-next/hardhat-viem-matchers",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/NomicFoundation/hardhat",
+    "directory": "v-next/hardhat-viem-matchers"
+  },
+  "author": "Nomic Foundation",
+  "license": "MIT",
+  "type": "module",
+  "types": "dist/src/index.d.ts",
+  "exports": {
+    ".": "./dist/src/index.js",
+    "./types": "./dist/src/types.js"
+  },
+  "keywords": [
+    "ethereum",
+    "smart-contracts",
+    "hardhat",
+    "hardhat-plugin",
+    "viem",
+    "matchers"
+  ],
+  "scripts": {
+    "lint": "pnpm prettier --check && pnpm eslint",
+    "lint:fix": "pnpm prettier --write && pnpm eslint --fix",
+    "eslint": "eslint \"src/**/*.ts\" \"test/**/*.ts\"",
+    "prettier": "prettier \"**/*.{ts,js,md,json}\"",
+    "test": "node --import tsx/esm --test --test-reporter=@nomicfoundation/hardhat-node-test-reporter \"test/*.ts\" \"test/!(fixture-projects|helpers)/**/*.ts\"",
+    "test:only": "node --import tsx/esm --test --test-only --test-reporter=@nomicfoundation/hardhat-node-test-reporter \"test/*.ts\" \"test/!(fixture-projects|helpers)/**/*.ts\"",
+    "test:coverage": "c8 --reporter html --reporter text --all --exclude test --exclude \"src/**/{types,type-extensions}.ts\" --src src node --import tsx/esm --test --test-reporter=@nomicfoundation/hardhat-node-test-reporter \"test/*.ts\" \"test/!(fixture-projects|helpers)/**/*.ts\"",
+    "pretest": "pnpm build",
+    "pretest:only": "pnpm build",
+    "build": "tsc --build .",
+    "prepublishOnly": "pnpm build",
+    "clean": "rimraf dist"
+  },
+  "files": [
+    "dist/src/",
+    "src/",
+    "CHANGELOG.md",
+    "LICENSE",
+    "README.md"
+  ],
+  "devDependencies": {
+    "@nomicfoundation/hardhat-node-test-reporter": "workspace:^3.0.0-next.11",
+    "@nomicfoundation/hardhat-test-utils": "workspace:^",
+    "@nomicfoundation/hardhat-viem": "workspace:^3.0.0-next.11",
+    "@types/node": "^20.14.9",
+    "c8": "^9.1.0",
+    "eslint": "9.25.1",
+    "expect-type": "^0.19.0",
+    "prettier": "3.2.5",
+    "rimraf": "^5.0.5",
+    "tsx": "^4.19.3",
+    "typescript": "~5.5.0",
+    "viem": "^2.30.0"
+  },
+  "dependencies": {
+    "@nomicfoundation/hardhat-errors": "workspace:^3.0.0-next.11",
+    "@nomicfoundation/hardhat-utils": "workspace:^3.0.0-next.11"
+  },
+  "peerDependencies": {
+    "@nomicfoundation/hardhat-viem": "workspace:^3.0.0-next.11",
+    "hardhat": "workspace:^3.0.0-next.11",
+    "viem": "^2.30.0"
+  }
+}

v-next/hardhat-viem-matchers/package.json

@@ -0,0 +1,22 @@
+import type { HardhatPlugin } from "hardhat/types/plugins";
+
+import "./type-extensions.js";
+
+const hardhatPlugin: HardhatPlugin = {
+  id: "hardhat-viem-matchers",
+  dependencies: [
+    async () => {
+      const { default: viemPlugin } = await import(
+        "@nomicfoundation/hardhat-viem"
+      );
+
+      return viemPlugin;
+    },
+  ],
+  hookHandlers: {
+    network: import.meta.resolve("./internal/hook-handlers/network.js"),
+  },
+  npmPackage: "@nomicfoundation/hardhat-viem-matchers",
+};
+
+export default hardhatPlugin;

v-next/hardhat-viem-matchers/src/index.ts

@@ -0,0 +1,25 @@
+import type { HookContext, NetworkHooks } from "hardhat/types/hooks";
+import type { ChainType, NetworkConnection } from "hardhat/types/network";
+
+import { initializeViemMatchers } from "../viem-matchers-initialization.js";
+
+export default async (): Promise<Partial<NetworkHooks>> => {
+  const handlers: Partial<NetworkHooks> = {
+    async newConnection<ChainTypeT extends ChainType | string>(
+      context: HookContext,
+      next: (
+        nextContext: HookContext,
+      ) => Promise<NetworkConnection<ChainTypeT>>,
+    ) {
+      const connection = await next(context);
+
+      connection.viem.assertions = await initializeViemMatchers(
+        connection.viem,
+      );
+
+      return connection;
+    },
+  };
+
+  return handlers;
+};

v-next/hardhat-viem-matchers/src/internal/hook-handlers/network.ts

@@ -0,0 +1,72 @@
+import type { HardhatViemHelpers } from "@nomicfoundation/hardhat-viem/types";
+import type { ChainType } from "hardhat/types/network";
+import type { Address, Hash } from "viem";
+
+import assert from "node:assert/strict";
+
+import { isHash } from "@nomicfoundation/hardhat-utils/eth";
+
+export async function balancesHaveChanged<
+  ChainTypeT extends ChainType | string = "generic",
+>(
+  viem: HardhatViemHelpers<ChainTypeT>,
+  txHash: Promise<Hash>,
+  changes: Array<{
+    address: Address;
+    amount: bigint;
+  }>,
+): Promise<void> {
+  const resolvedTxHash = await txHash;
+
+  assert.ok(
+    isHash(resolvedTxHash),
+    `The promise should return a transaction hash, but it returned: ${String(resolvedTxHash)}`,
+  );
+
+  const publicClient = await viem.getPublicClient();
+
+  const receipt = await publicClient.waitForTransactionReceipt({
+    hash: resolvedTxHash,
+  });
+
+  const senderAddress = receipt.from;
+  const blockNrAfterTx = receipt.blockNumber;
+
+  const beforeBalances = await Promise.all(
+    changes.map(({ address }) =>
+      publicClient.getBalance({
+        address,
+        blockNumber: blockNrAfterTx - 1n,
+      }),
+    ),
+  );
+
+  const afterBalances = await Promise.all(
+    changes.map(async ({ address }) => {
+      let balance = await publicClient.getBalance({
+        address,
+        blockNumber: blockNrAfterTx,
+      });
+
+      if (address === senderAddress) {
+        const senderGasFee = receipt.effectiveGasPrice * receipt.gasUsed;
+        balance = balance + senderGasFee;
+      }
+
+      return balance;
+    }),
+  );
+
+  changes.forEach(({ address, amount }, index) => {
+    const balanceBefore = beforeBalances[index];
+    const balanceAfter = afterBalances[index];
+
+    const actualChange = balanceAfter - balanceBefore;
+
+    assert.equal(
+      actualChange,
+      amount,
+      `For address "${address}", expected balance to change by ${amount} (from ${balanceBefore} to ${balanceBefore + amount}), but got a change of ${actualChange} instead.`,
+    );
+  });
+}

v-next/hardhat-viem-matchers/src/internal/matchers/balances-have-changed.ts

@@ -0,0 +1,59 @@
+import type {
+  ContractAbis,
+  ContractReturnType,
+  HardhatViemHelpers,
+} from "@nomicfoundation/hardhat-viem/types";
+import type { ChainType } from "hardhat/types/network";
+import type {
+  AbiEvent,
+  ContractEventName,
+  ReadContractReturnType,
+  WriteContractReturnType,
+} from "viem";
+
+import assert from "node:assert/strict";
+
+import { parseEventLogs } from "viem";
+
+export async function handleEmit<
+  ContractName extends keyof ContractAbis,
+  EventName extends ContractEventName<ContractAbis[ContractName]>,
+  ChainTypeT extends ChainType | string = "generic",
+>(
+  viem: HardhatViemHelpers<ChainTypeT>,
+  contractFn: Promise<ReadContractReturnType | WriteContractReturnType>,
+  contract: ContractReturnType<ContractName>,
+  eventName: EventName,
+): Promise<Array<{ args?: Record<string, any> }>> {
+  const abiEvents: AbiEvent[] = contract.abi.filter(
+    (item): item is AbiEvent =>
+      item.type === "event" && item.name === eventName,
+  );
+
+  assert.ok(
+    abiEvents.length !== 0,
+    `Event "${eventName}" not found in the contract ABI`,
+  );
+
+  await contractFn;
+
+  const publicClient = await viem.getPublicClient();
+
+  const logs = await publicClient.getLogs({
+    address: contract.address,
+  });
+
+  const parsedLogs = parseEventLogs({
+    abi: contract.abi,
+    eventName,
+    logs,
+  });
+
+  assert.ok(
+    parsedLogs.length > 0,
+    `No events were emitted for contract with address "${contract.address}" and event name "${eventName}"`,
+  );
+
+  // eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- logs generated from emitted events have the `args` field
+  return parsedLogs as unknown as Array<{ args?: Record<string, any> }>;
+}