🦷 Automatically inject call history into hardhat provider (#776)

Author: rzadp

.changeset/modern-tools-drop.md

@@ -0,0 +1,7 @@
+---
+"@ethereum-waffle/chai": patch
+"@ethereum-waffle/hardhat": patch
+"@ethereum-waffle/optimism": patch
+---
+
+🦷 (Experimental) Automatically inject call history into hardhat provider

waffle-chai/.mocharc.js

@@ -2,5 +2,6 @@ process.env.NODE_ENV = 'test'
 module.exports = {
   require: 'ts-node/register/transpile-only',
   timeout: 50000,
-  spec: 'test/**/*.{js,ts}'
+  spec: 'test/**/*.{js,ts}',
+  file: 'test/test-setup.ts'
 }

waffle-chai/src/index.ts

@@ -15,6 +15,7 @@ import {supportChangeTokenBalance} from './matchers/changeTokenBalance';
 import {supportChangeTokenBalances} from './matchers/changeTokenBalances';
 import {supportCalledOnContract} from './matchers/calledOnContract/calledOnContract';
 import {supportCalledOnContractWith} from './matchers/calledOnContract/calledOnContractWith';
+import './inject-call-history';
 
 export function waffleChai(chai: Chai.ChaiStatic, utils: Chai.ChaiUtils) {
   supportBigNumber(chai.Assertion, utils);

waffle-chai/src/inject-call-history.ts

@@ -0,0 +1,78 @@
+import type {RecordedCall} from '@ethereum-waffle/provider';
+import {utils} from 'ethers';
+
+/**
+ * Injects call history into hardhat provider,
+ * making it possible to use matchers like calledOnContract
+ */
+
+class CallHistory {
+  recordedCalls: RecordedCall[] = [];
+
+  addUniqueCall(call: RecordedCall) {
+    if (!this.recordedCalls.find(c => c.address === call.address && c.data === call.data)) {
+      this.recordedCalls.push(call);
+    }
+  }
+
+  clearAll() {
+    this.recordedCalls = [];
+  }
+}
+
+function toRecordedCall(message: any): RecordedCall {
+  return {
+    address: message.to?.buf ? utils.getAddress(utils.hexlify(message.to.buf)) : undefined,
+    data: message.data ? utils.hexlify(message.data) : '0x'
+  };
+}
+
+const inject = () => {
+  let waffle: any;
+  try {
+    waffle = require('hardhat')?.waffle;
+  } catch { return; }
+  if (!waffle || !waffle.provider) return;
+  const callHistory = new CallHistory();
+  (waffle.provider as any).clearCallHistory = () => {
+    callHistory.clearAll();
+  };
+
+  let beforeMessageListener: (message: any) => void | undefined;
+  const init = waffle.provider?._hardhatNetwork?.provider?._wrapped?._wrapped?._wrapped?._init;
+  if (!init) return;
+  waffle.provider._hardhatNetwork.provider._wrapped._wrapped._wrapped._init = async function () {
+    await init.apply(this);
+    if (typeof beforeMessageListener === 'function') {
+    // has to be here because of weird behaviour of init function, which requires us to re-register the handler.
+      waffle.provider
+        ?._hardhatNetwork
+        ?.provider
+        ?._wrapped
+        ?._wrapped
+        ?._wrapped
+        ?._node
+        ?._vmTracer
+        ?._vm
+        ?.off?.('beforeMessage', beforeMessageListener);
+    }
+    beforeMessageListener = (message: any) => {
+      callHistory.addUniqueCall(toRecordedCall(message));
+    };
+    waffle.provider.callHistory = callHistory.recordedCalls;
+    waffle.provider
+      ?._hardhatNetwork.provider
+      ?._wrapped._wrapped
+      ?._wrapped
+      ?._node
+      ?._vmTracer
+      ?._vm
+      ?.on?.('beforeMessage', beforeMessageListener);
+  };
+};
+
+let injected = false;
+if (!injected && !!process.env.WAFFLE_EXPERIMENTAL_HARDHAT_CALL_HISTORY) {
+  injected = true;
+  inject();
+}

waffle-chai/test/index.ts

@@ -1,10 +1,3 @@
-import chai from 'chai';
-import chaiAsPromised from 'chai-as-promised';
-import {waffleChai} from '../src';
-
-chai.use(chaiAsPromised);
-chai.use(waffleChai);
-
 export {calledOnContractTest} from './matchers/calledOnContract/calledOnContractTest';
 export {calledOnContractValidatorsTest} from './matchers/calledOnContract/calledOnContractValidatorsTest';
 export {calledOnContractWithTest} from './matchers/calledOnContract/calledOnContractWithTest';

waffle-chai/test/test-setup.ts

@@ -0,0 +1,6 @@
+import chai from 'chai';
+import chaiAsPromised from 'chai-as-promised';
+import {waffleChai} from '../src';
+
+chai.use(chaiAsPromised);
+chai.use(waffleChai);

waffle-hardhat/.mocharc.js

@@ -1,4 +1,5 @@
 process.env.NODE_ENV = 'test'
+process.env.WAFFLE_EXPERIMENTAL_HARDHAT_CALL_HISTORY = true
 module.exports = {
   require: 'ts-node/register/transpile-only',
   timeout: 50000,

waffle-hardhat/src/inject-call-history.ts

@@ -1 +1,6 @@
-import '../src/inject-call-history';
+import chai from 'chai';
+import chaiAsPromised from 'chai-as-promised';
+import {solidity} from 'ethereum-waffle';
+
+chai.use(chaiAsPromised);
+chai.use(solidity);

waffle-hardhat/test/test-setup.ts

@@ -2,5 +2,6 @@ process.env.NODE_ENV = 'test'
 module.exports = {
   require: 'ts-node/register/transpile-only',
   timeout: 50000,
-  spec: 'test/**/*.test.{js,ts}'
+  spec: 'test/**/*.test.{js,ts}',
+  file: 'test/test-setup.ts'
 }

waffle-optimism/.mocharc.js

@@ -0,0 +1,6 @@
+import chai from 'chai';
+import chaiAsPromised from 'chai-as-promised';
+import {solidity} from 'ethereum-waffle';
+
+chai.use(chaiAsPromised);
+chai.use(solidity);