🗿 Add error to balance changing matchers (#814)

pawelpolak2 · web-flow · commit b54c6b93dee7 · 2023-01-03T16:43:57.000+01:00
* 🗿 Add error to balance changing matchers
diff --git a/.changeset/quiet-pumas-double.md b/.changeset/quiet-pumas-double.md
@@ -0,0 +1,5 @@
+---
+"@ethereum-waffle/chai": patch
+---
+
+Add delta to balance changing matchers
diff --git a/waffle-chai/src/matchers/changeEtherBalance.ts b/waffle-chai/src/matchers/changeEtherBalance.ts
@@ -31,14 +31,29 @@ export function supportChangeEtherBalance(Assertion: Chai.AssertionStatic) {
     }).then(([actualChange, address]: [BigNumber, string]) => {
       const isCurrentlyNegated = this.__flags.negate === true;
       this.__flags.negate = isNegated;
-      this.assert(
-        actualChange.eq(BigNumber.from(balanceChange)),
-        `Expected "${address}" to change balance by ${balanceChange} wei, ` +
-          `but it has changed by ${actualChange} wei`,
-        `Expected "${address}" to not change balance by ${balanceChange} wei,`,
-        balanceChange,
-        actualChange
-      );
+      const margin = options?.errorMargin ? options.errorMargin : '0';
+      if (BigNumber.from(margin).eq(0)) {
+        this.assert(
+          actualChange.eq(BigNumber.from(balanceChange)),
+          `Expected "${address}" to change balance by ${balanceChange} wei, ` +
+            `but it has changed by ${actualChange} wei`,
+          `Expected "${address}" to not change balance by ${balanceChange} wei,`,
+          balanceChange,
+          actualChange
+        );
+      } else {
+        const low = BigNumber.from(balanceChange).sub(margin);
+        const high = BigNumber.from(balanceChange).add(margin);
+        this.assert(
+          actualChange.lte(high) &&
+          actualChange.gte(low),
+          `Expected "${address}" balance to change within [${[low, high]}] wei, ` +
+            `but it has changed by ${actualChange} wei`,
+          `Expected "${address}" balance to not change within [${[low, high]}] wei`,
+          balanceChange,
+          actualChange
+        );
+      }
       this.__flags.negate = isCurrentlyNegated;
     }
     );
diff --git a/waffle-chai/src/matchers/changeEtherBalances.ts b/waffle-chai/src/matchers/changeEtherBalances.ts
@@ -30,16 +30,34 @@ export function supportChangeEtherBalances(Assertion: Chai.AssertionStatic) {
     }).then(([actualChanges, accountAddresses]: [BigNumber[], string[]]) => {
       const isCurrentlyNegated = this.__flags.negate === true;
       this.__flags.negate = isNegated;
-      this.assert(
-        actualChanges.every((change, ind) =>
-          change.eq(BigNumber.from(balanceChanges[ind]))
-        ),
-        `Expected ${accountAddresses} to change balance by ${balanceChanges} wei, ` +
-          `but it has changed by ${actualChanges} wei`,
-        `Expected ${accountAddresses} to not change balance by ${balanceChanges} wei,`,
-        balanceChanges.map((balanceChange) => balanceChange.toString()),
-        actualChanges.map((actualChange) => actualChange.toString())
-      );
+      const margin = options?.errorMargin ? options.errorMargin : '0';
+      if (BigNumber.from(margin).eq(0)) {
+        this.assert(
+          actualChanges.every((change, ind) =>
+            change.lte(BigNumber.from(balanceChanges[ind]).add(margin)) &&
+            change.gte(BigNumber.from(balanceChanges[ind]).sub(margin))
+          ),
+          `Expected ${accountAddresses} to change balance by ${balanceChanges} wei, ` +
+            `but it has changed by ${actualChanges} wei`,
+          `Expected ${accountAddresses} to not change balance by ${balanceChanges} wei,`,
+          balanceChanges.map((balanceChange) => balanceChange.toString()),
+          actualChanges.map((actualChange) => actualChange.toString())
+        );
+      } else {
+        actualChanges.forEach((change, ind) => {
+          const low = BigNumber.from(balanceChanges[ind]).sub(margin);
+          const high = BigNumber.from(balanceChanges[ind]).add(margin);
+          this.assert(
+            change.lte(high) &&
+            change.gte(low),
+            `Expected "${accountAddresses[ind]}" balance to change within [${[low, high]}] wei, ` +
+              `but it has changed by ${change} wei`,
+            `Expected "${accountAddresses[ind]}" balance to not change within [${[low, high]}] wei`,
+            balanceChanges[ind],
+            change
+          );
+        });
+      }
       this.__flags.negate = isCurrentlyNegated;
     });
     this.then = derivedPromise.then.bind(derivedPromise);
diff --git a/waffle-chai/src/matchers/changeTokenBalance.ts b/waffle-chai/src/matchers/changeTokenBalance.ts
@@ -7,7 +7,8 @@ export function supportChangeTokenBalance(Assertion: Chai.AssertionStatic) {
     this: any,
     token: Contract,
     account: Account | string,
-    balanceChange: BigNumberish
+    balanceChange: BigNumberish,
+    errorMargin : BigNumberish
   ) {
     callPromise(this);
     const isNegated = this.__flags.negate === true;
@@ -21,14 +22,30 @@ export function supportChangeTokenBalance(Assertion: Chai.AssertionStatic) {
     }).then(([actualChange, address]: [BigNumber, string]) => {
       const isCurrentlyNegated = this.__flags.negate === true;
       this.__flags.negate = isNegated;
-      this.assert(
-        actualChange.eq(BigNumber.from(balanceChange)),
-        `Expected "${address}" to change balance by ${balanceChange} wei, ` +
-          `but it has changed by ${actualChange} wei`,
-        `Expected "${address}" to not change balance by ${balanceChange} wei,`,
-        balanceChange,
-        actualChange
-      );
+      if (errorMargin === undefined) errorMargin = '0';
+      if (BigNumber.from(errorMargin).eq(0)) {
+        this.assert(
+          actualChange.lte(BigNumber.from(balanceChange).add(errorMargin)) &&
+          actualChange.gte(BigNumber.from(balanceChange).sub(errorMargin)),
+          `Expected "${address}" to change balance by ${balanceChange} wei, ` +
+            `but it has changed by ${actualChange} wei`,
+          `Expected "${address}" to not change balance by ${balanceChange} wei,`,
+          balanceChange,
+          actualChange
+        );
+      } else {
+        const low = BigNumber.from(balanceChange).sub(errorMargin);
+        const high = BigNumber.from(balanceChange).add(errorMargin);
+        this.assert(
+          actualChange.lte(high) &&
+          actualChange.gte(low),
+          `Expected "${address}" balance to change within [${[low, high]}] wei, ` +
+            `but it has changed by ${actualChange} wei`,
+          `Expected "${address}" balance to not change within [${[low, high]}] wei`,
+          balanceChange,
+          actualChange
+        );
+      }
       this.__flags.negate = isCurrentlyNegated;
     });
     this.then = derivedPromise.then.bind(derivedPromise);
diff --git a/waffle-chai/src/matchers/changeTokenBalances.ts b/waffle-chai/src/matchers/changeTokenBalances.ts
@@ -7,7 +7,8 @@ export function supportChangeTokenBalances(Assertion: Chai.AssertionStatic) {
     this: any,
     token: Contract,
     accounts: (Account | string)[],
-    balanceChanges: BigNumberish[]
+    balanceChanges: BigNumberish[],
+    errorMargin: BigNumberish
   ) {
     callPromise(this);
     const isNegated = this.__flags.negate === true;
@@ -21,16 +22,34 @@ export function supportChangeTokenBalances(Assertion: Chai.AssertionStatic) {
     }).then(([actualChanges, accountAddresses]: [BigNumber[], string[]]) => {
       const isCurrentlyNegated = this.__flags.negate === true;
       this.__flags.negate = isNegated;
-      this.assert(
-        actualChanges.every((change, ind) =>
-          change.eq(BigNumber.from(balanceChanges[ind]))
-        ),
-        `Expected ${accountAddresses} to change balance by ${balanceChanges} wei, ` +
-          `but it has changed by ${actualChanges} wei`,
-        `Expected ${accountAddresses} to not change balance by ${balanceChanges} wei,`,
-        balanceChanges.map((balanceChange) => balanceChange.toString()),
-        actualChanges.map((actualChange) => actualChange.toString())
-      );
+      if (errorMargin === undefined) errorMargin = '0';
+      if (BigNumber.from(errorMargin).eq(0)) {
+        this.assert(
+          actualChanges.every((change, ind) =>
+            change.lte(BigNumber.from(balanceChanges[ind]).add(errorMargin)) &&
+            change.gte(BigNumber.from(balanceChanges[ind]).sub(errorMargin))
+          ),
+          `Expected ${accountAddresses} to change balance by ${balanceChanges} wei, ` +
+            `but it has changed by ${actualChanges} wei`,
+          `Expected ${accountAddresses} to not change balance by ${balanceChanges} wei,`,
+          balanceChanges.map((balanceChange) => balanceChange.toString()),
+          actualChanges.map((actualChange) => actualChange.toString())
+        );
+      } else {
+        actualChanges.forEach((change, ind) => {
+          const low = BigNumber.from(balanceChanges[ind]).sub(errorMargin);
+          const high = BigNumber.from(balanceChanges[ind]).add(errorMargin);
+          this.assert(
+            change.lte(high) &&
+            change.gte(low),
+            `Expected "${accountAddresses[ind]}" balance to change within [${[low, high]}] wei, ` +
+              `but it has changed by ${change} wei`,
+            `Expected "${accountAddresses[ind]}" balance to not change within [${[low, high]}] wei`,
+            balanceChanges[ind],
+            change
+          );
+        });
+      }
       this.__flags.negate = isCurrentlyNegated;
     });
     this.then = derivedPromise.then.bind(derivedPromise);
diff --git a/waffle-chai/src/matchers/misc/balance.ts b/waffle-chai/src/matchers/misc/balance.ts
@@ -1,8 +1,10 @@
+import {BigNumberish} from 'ethers';
 import {ensure} from '../calledOnContract/utils';
 import {Account, getAddressOf} from './account';
 
 export interface BalanceChangeOptions {
   includeFee?: boolean;
+  errorMargin?: BigNumberish;
 }
 
 export function getAddresses(accounts: Account[]) {
diff --git a/waffle-chai/src/types.ts b/waffle-chai/src/types.ts
@@ -23,8 +23,8 @@ declare namespace Chai {
     changeBalances(accounts: any[], balances: any[]): AsyncAssertion;
     changeEtherBalance(account: any, balance: any, options?: any): AsyncAssertion;
     changeEtherBalances(accounts: any[], balances: any[], options?: any): AsyncAssertion;
-    changeTokenBalance(token: any, account: any, balance: any): AsyncAssertion;
-    changeTokenBalances(token: any, accounts: any[], balances: any[]): AsyncAssertion;
+    changeTokenBalance(token: any, account: any, balance: any, errorMargin?: any): AsyncAssertion;
+    changeTokenBalances(token: any, accounts: any[], balances: any[], errorMargin?: any): AsyncAssertion;
     calledOnContract(contract: any): void;
     calledOnContractWith(contract: any, parameters: any[]): void;
   }
diff --git a/waffle-chai/test/matchers/changeEtherBalanceTest.ts b/waffle-chai/test/matchers/changeEtherBalanceTest.ts
@@ -234,5 +234,71 @@ export const changeEtherBalanceTest = (
         ).to.changeEtherBalance(contract, 200);
       });
     });
+
+    describe('Change balance, error margin', () => {
+      it('positive', async () => {
+        await expect(sender.sendTransaction({
+          to: receiver.address,
+          value: 200
+        })).to.changeEtherBalance(receiver, 300, {errorMargin: 100});
+
+        await expect(sender.sendTransaction({
+          to: receiver.address,
+          value: 200
+        })).to.changeEtherBalance(receiver, 100, {errorMargin: 100});
+      });
+
+      it('negative', async () => {
+        await expect(sender.sendTransaction({
+          to: receiver.address,
+          value: 200
+        })).to.not.changeEtherBalance(receiver, 300, {errorMargin: 99});
+
+        await expect(sender.sendTransaction({
+          to: receiver.address,
+          value: 200
+        })).to.not.changeEtherBalance(receiver, 100, {errorMargin: 99});
+      });
+
+      describe('Throws', () => {
+        it('too low', async () => {
+          await expect(
+            expect(await sender.sendTransaction({
+              to: receiver.address,
+              value: 200
+            })).to.changeEtherBalance(receiver, 250, {errorMargin: 40})
+          ).to.be.eventually.rejectedWith(
+            AssertionError,
+            `Expected "${receiver.address}" balance to change within [210,290] wei, ` +
+            'but it has changed by 200 wei'
+          );
+        });
+
+        it('too high', async () => {
+          await expect(
+            expect(await sender.sendTransaction({
+              to: receiver.address,
+              value: 300
+            })).to.changeEtherBalance(receiver, 250, {errorMargin: 40})
+          ).to.be.eventually.rejectedWith(
+            AssertionError,
+            `Expected "${receiver.address}" balance to change within [210,290] wei, ` +
+            'but it has changed by 300 wei'
+          );
+        });
+
+        it('negated', async () => {
+          await expect(
+            expect(await sender.sendTransaction({
+              to: receiver.address,
+              value: 250
+            })).to.not.changeEtherBalance(receiver, 250, {errorMargin: 40})
+          ).to.be.eventually.rejectedWith(
+            AssertionError,
+            `Expected "${receiver.address}" balance to not change within [210,290] wei`
+          );
+        });
+      });
+    });
   });
 };
diff --git a/waffle-chai/test/matchers/changeEtherBalancesTest.ts b/waffle-chai/test/matchers/changeEtherBalancesTest.ts
@@ -238,4 +238,73 @@ export const changeEtherBalancesTest = (
       });
     });
   });
+
+  describe('changeEtherBalances - error margin', () => {
+    it('positive', async () => {
+      await expect(sender.sendTransaction({
+        to: receiver.address,
+        value: 200
+      })).to.changeEtherBalances([receiver, sender], [300, -300], {errorMargin: 100});
+    });
+
+    it('negative', async () => {
+      await expect(sender.sendTransaction({
+        to: receiver.address,
+        value: 200
+      })).to.not.changeEtherBalances([receiver, sender], [300, -300], {errorMargin: 99});
+    });
+
+    describe('Throws', () => {
+      it('too high', async () => {
+        await expect(
+          expect(await sender.sendTransaction({
+            to: receiver.address,
+            value: 300
+          })).to.changeEtherBalances([receiver, sender], [250, -250], {errorMargin: 40})
+        ).to.be.eventually.rejectedWith(
+          AssertionError,
+          `Expected "${receiver.address}" balance to change within [210,290] wei, ` +
+          'but it has changed by 300 wei'
+        );
+      });
+
+      it('too low', async () => {
+        await expect(
+          expect(await sender.sendTransaction({
+            to: receiver.address,
+            value: 200
+          })).to.changeEtherBalances([receiver, sender], [250, -250], {errorMargin: 40})
+        ).to.be.eventually.rejectedWith(
+          AssertionError,
+          `Expected "${receiver.address}" balance to change within [210,290] wei, ` +
+          'but it has changed by 200 wei'
+        );
+      });
+
+      it('negated', async () => {
+        await expect(
+          expect(await sender.sendTransaction({
+            to: receiver.address,
+            value: 300
+          })).to.not.changeEtherBalances([receiver, sender], [290, -290], {errorMargin: 40})
+        ).to.be.eventually.rejectedWith(
+          AssertionError,
+          `Expected "${receiver.address}" balance to not change within [250,330] wei`
+        );
+      });
+
+      it('second address', async () => {
+        await expect(
+          expect(await sender.sendTransaction({
+            to: receiver.address,
+            value: 200
+          })).to.changeEtherBalances([receiver, sender], [210, -250], {errorMargin: 40})
+        ).to.be.eventually.rejectedWith(
+          AssertionError,
+          `Expected "${sender.address}" balance to change within [-290,-210] wei, ` +
+          'but it has changed by -200 wei'
+        );
+      });
+    });
+  });
 };
diff --git a/waffle-chai/test/matchers/changeTokenBalanceTest.ts b/waffle-chai/test/matchers/changeTokenBalanceTest.ts
diff --git a/waffle-chai/test/matchers/changeTokenBalancesTest.ts b/waffle-chai/test/matchers/changeTokenBalancesTest.ts

Original file line number	Diff line number	Diff line change
`@@ -1,8 +1,10 @@`
	`1`	`+import {BigNumberish} from 'ethers';`
`1`	`2`	`import {ensure} from '../calledOnContract/utils';`
`2`	`3`	`import {Account, getAddressOf} from './account';`
`3`	`4`
`4`	`5`	`export interface BalanceChangeOptions {`
`5`	`6`	`includeFee?: boolean;`
	`7`	`+ errorMargin?: BigNumberish;`
`6`	`8`	`}`
`7`	`9`
`8`	`10`	`export function getAddresses(accounts: Account[]) {`