From 9b4d092efa6b22a4cb15e25f2006f14b1a3e2816 Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Wed, 1 Sep 2021 19:17:00 -0500
Subject: [PATCH 01/13] add tests for ArrayBuffers

---
 packages/expect/src/__tests__/matchers.test.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/packages/expect/src/__tests__/matchers.test.js b/packages/expect/src/__tests__/matchers.test.js
index 81ceabf09c81..ed9fdaff4b33 100644
--- a/packages/expect/src/__tests__/matchers.test.js
+++ b/packages/expect/src/__tests__/matchers.test.js
@@ -426,6 +426,10 @@ describe('.toStrictEqual()', () => {
   it('does not pass when equally sparse arrays have different values', () => {
     expect([, 1]).not.toStrictEqual([, 2]);
   });
+
+  it('does not pass when ArrayBuffers are not equal', () => {
+    expect(Uint8Array.from([1, 2]).buffer).not.toStrictEqual(Uint8Array.from([0, 0]).buffer);
+  })
   /* eslint-enable */
 });
 

From c5fd617cdcd20e31ae3ed7f8f9b23ff68e6e2f2c Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Wed, 1 Sep 2021 19:48:50 -0500
Subject: [PATCH 02/13] add arrayBufferEquality util function

---
 packages/expect/src/matchers.ts |  2 ++
 packages/expect/src/utils.ts    | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/packages/expect/src/matchers.ts b/packages/expect/src/matchers.ts
index d0ec1480dab4..344374330cb6 100644
--- a/packages/expect/src/matchers.ts
+++ b/packages/expect/src/matchers.ts
@@ -40,6 +40,7 @@ import {
 } from './print';
 import type {MatcherState, MatchersObject} from './types';
 import {
+  arrayBufferEquality,
   getObjectSubset,
   getPath,
   iterableEquality,
@@ -61,6 +62,7 @@ const toStrictEqualTesters = [
   iterableEquality,
   typeEquality,
   sparseArrayEquality,
+  arrayBufferEquality,
 ];
 
 type ContainIterable =
diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 858f7a7d03cb..25414b23f4ee 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -319,6 +319,30 @@ export const typeEquality = (a: any, b: any): boolean | undefined => {
   return false;
 };
 
+// eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
+export const arrayBufferEquality = (a: any, b: any): boolean | undefined => {
+  if (!(a instanceof ArrayBuffer) || !(b instanceof ArrayBuffer)) {
+    return undefined;
+  }
+
+  const d1 = new DataView(a);
+  const d2 = new DataView(b);
+
+  // Buffers are not equal when they do not have the same byte length
+  if (d1.byteLength != d2.byteLength) {
+    return false;
+  }
+
+  // Compare each arraryBuffer byte's buffers
+  for (let i = 0;i < d1.byteLength; i++) {
+    if (d1.getUint8(i) != d2.getUint8(i)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 export const sparseArrayEquality = (
   a: unknown,
   b: unknown,

From 5d6bcf1caafe86cad9c88206486f5d19a759770e Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Wed, 1 Sep 2021 20:11:51 -0500
Subject: [PATCH 03/13] enhance variable names

---
 packages/expect/src/utils.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 25414b23f4ee..86bb04dcae2c 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -325,17 +325,17 @@ export const arrayBufferEquality = (a: any, b: any): boolean | undefined => {
     return undefined;
   }
 
-  const d1 = new DataView(a);
-  const d2 = new DataView(b);
+  const dataViewA = new DataView(a);
+  const dataViewB = new DataView(b);
 
   // Buffers are not equal when they do not have the same byte length
-  if (d1.byteLength != d2.byteLength) {
+  if (dataViewA.byteLength != dataViewB.byteLength) {
     return false;
   }
 
   // Compare each arraryBuffer byte's buffers
-  for (let i = 0;i < d1.byteLength; i++) {
-    if (d1.getUint8(i) != d2.getUint8(i)) {
+  for (let i = 0;i < dataViewA.byteLength; i++) {
+    if (dataViewA.getUint8(i) != dataViewB.getUint8(i)) {
       return false;
     }
   }

From feae86f4cfa1342f08f08e83a8e0e18918c50f5b Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Wed, 1 Sep 2021 20:12:00 -0500
Subject: [PATCH 04/13] add tests

---
 .../expect/src/__tests__/matchers.test.js     |  8 +++++++
 packages/expect/src/__tests__/utils.test.ts   | 21 +++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/packages/expect/src/__tests__/matchers.test.js b/packages/expect/src/__tests__/matchers.test.js
index ed9fdaff4b33..6ee3810c6c61 100644
--- a/packages/expect/src/__tests__/matchers.test.js
+++ b/packages/expect/src/__tests__/matchers.test.js
@@ -429,6 +429,14 @@ describe('.toStrictEqual()', () => {
 
   it('does not pass when ArrayBuffers are not equal', () => {
     expect(Uint8Array.from([1, 2]).buffer).not.toStrictEqual(Uint8Array.from([0, 0]).buffer);
+    expect(Uint8Array.from([2,1]).buffer).not.toStrictEqual(Uint8Array.from([2,2]).buffer);
+    expect(Uint8Array.from([]).buffer).not.toStrictEqual(Uint8Array.from([1]).buffer);
+  });
+
+  it('passes for matching buffers', () => {
+    expect(Uint8Array.from([1]).buffer).toStrictEqual(Uint8Array.from([1]).buffer);
+    expect(Uint8Array.from([]).buffer).toStrictEqual(Uint8Array.from([]).buffer);
+    expect(Uint8Array.from([9,3]).buffer).toStrictEqual(Uint8Array.from([9,3]).buffer);
   })
   /* eslint-enable */
 });
diff --git a/packages/expect/src/__tests__/utils.test.ts b/packages/expect/src/__tests__/utils.test.ts
index c210abf9fb34..0d25692dbd02 100644
--- a/packages/expect/src/__tests__/utils.test.ts
+++ b/packages/expect/src/__tests__/utils.test.ts
@@ -8,6 +8,7 @@
 
 import {stringify} from 'jest-matcher-utils';
 import {
+  arrayBufferEquality,
   emptyObject,
   getObjectSubset,
   getPath,
@@ -466,3 +467,23 @@ describe('iterableEquality', () => {
     expect(iterableEquality(a, b)).toBe(true);
   });
 });
+
+describe('arrayBufferEquality', () => {
+  test('returns undefined if given a non instance of ArrayBuffer', () => {
+    expect(arrayBufferEquality(2, "s")).toBeUndefined();
+    expect(arrayBufferEquality(undefined, 2)).toBeUndefined();
+    expect(arrayBufferEquality(new Date(), new ArrayBuffer(2))).toBeUndefined();
+  });
+
+  test('returns false when given non-matching buffers', () => {
+    const a = Uint8Array.from([2,4]).buffer;
+    const b = Uint8Array.from([1,7]).buffer;
+    expect(arrayBufferEquality(a, b)).not.toBeTruthy();
+  });
+
+  test('returns true when given matching buffers', () => {
+    const a = Uint8Array.from([1,2]).buffer;
+    const b = Uint8Array.from([1,2]).buffer;
+    expect(arrayBufferEquality(a, b)).toBeTruthy();
+  })
+});

From 88ebc4a2a62f10d5b72993a7f7ac9928635d00db Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Wed, 1 Sep 2021 20:23:18 -0500
Subject: [PATCH 05/13] fix typo in comment

---
 packages/expect/src/utils.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 86bb04dcae2c..e5db26679e87 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -333,7 +333,7 @@ export const arrayBufferEquality = (a: any, b: any): boolean | undefined => {
     return false;
   }
 
-  // Compare each arraryBuffer byte's buffers
+  // Check if every byte value is equal to each other
   for (let i = 0;i < dataViewA.byteLength; i++) {
     if (dataViewA.getUint8(i) != dataViewB.getUint8(i)) {
       return false;

From 528017484864a0f8a5f892d1e3db5606d95d395b Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Wed, 1 Sep 2021 20:32:47 -0500
Subject: [PATCH 06/13] Update CHANGELOG.md

---
 CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0af283259c24..71ce881d032e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ### Features
 
+- `[expect]` Add equality checks for Array Buffers in `expect.ToStrictEqual()`
+
 ### Fixes
 
 ### Chore & Maintenance

From 6106e3ad252388bc716ed54ef3c900be9bd0756d Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Thu, 2 Sep 2021 06:24:58 -0500
Subject: [PATCH 07/13] Update CHANGELOG.md

Co-authored-by: Simen Bekkhus <sbekkhus91@gmail.com>
---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 71ce881d032e..0235fc8a2519 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ### Features
 
-- `[expect]` Add equality checks for Array Buffers in `expect.ToStrictEqual()`
+- `[expect]` Add equality checks for Array Buffers in `expect.ToStrictEqual()` ([#11805](https://github.com/facebook/jest/pull/11805))
 
 ### Fixes
 

From 2cdd879de55938887acaf401ccc90216cce3e48b Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Thu, 2 Sep 2021 06:25:19 -0500
Subject: [PATCH 08/13] Update packages/expect/src/utils.ts

Co-authored-by: Simen Bekkhus <sbekkhus91@gmail.com>
---
 packages/expect/src/utils.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index e5db26679e87..944c2b40e178 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -329,7 +329,7 @@ export const arrayBufferEquality = (a: any, b: any): boolean | undefined => {
   const dataViewB = new DataView(b);
 
   // Buffers are not equal when they do not have the same byte length
-  if (dataViewA.byteLength != dataViewB.byteLength) {
+  if (dataViewA.byteLength !== dataViewB.byteLength) {
     return false;
   }
 

From 7b7d45492996ef60f78d4ef458a36cb69fc6a562 Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Thu, 2 Sep 2021 06:28:12 -0500
Subject: [PATCH 09/13] Update packages/expect/src/utils.ts

Co-authored-by: Simen Bekkhus <sbekkhus91@gmail.com>
---
 packages/expect/src/utils.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 944c2b40e178..75bad1b02fce 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -320,7 +320,7 @@ export const typeEquality = (a: any, b: any): boolean | undefined => {
 };
 
 // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
-export const arrayBufferEquality = (a: any, b: any): boolean | undefined => {
+export const arrayBufferEquality = (a: unknown, b: unknown): boolean | undefined => {
   if (!(a instanceof ArrayBuffer) || !(b instanceof ArrayBuffer)) {
     return undefined;
   }

From 5e34616227a1d16934966d6f4ca29842205e0d18 Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Thu, 2 Sep 2021 06:28:55 -0500
Subject: [PATCH 10/13] Update utils.ts

---
 packages/expect/src/utils.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 75bad1b02fce..3c3e73b27b0e 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -319,7 +319,6 @@ export const typeEquality = (a: any, b: any): boolean | undefined => {
   return false;
 };
 
-// eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
 export const arrayBufferEquality = (a: unknown, b: unknown): boolean | undefined => {
   if (!(a instanceof ArrayBuffer) || !(b instanceof ArrayBuffer)) {
     return undefined;

From f4c9037f912b3de12bfbb04cb7665ff5313e2839 Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Thu, 2 Sep 2021 06:30:44 -0500
Subject: [PATCH 11/13] Update packages/expect/src/utils.ts

Co-authored-by: Simen Bekkhus <sbekkhus91@gmail.com>
---
 packages/expect/src/utils.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 3c3e73b27b0e..6a1c622f2a63 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -334,7 +334,7 @@ export const arrayBufferEquality = (a: unknown, b: unknown): boolean | undefined
 
   // Check if every byte value is equal to each other
   for (let i = 0;i < dataViewA.byteLength; i++) {
-    if (dataViewA.getUint8(i) != dataViewB.getUint8(i)) {
+    if (dataViewA.getUint8(i) !== dataViewB.getUint8(i)) {
       return false;
     }
   }

From 41cc53d6bfca909ec7579c48d3fcd157172fb7ef Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Thu, 2 Sep 2021 06:56:16 -0500
Subject: [PATCH 12/13] follow style standards

---
 packages/expect/src/__tests__/matchers.test.js | 2 +-
 packages/expect/src/__tests__/utils.test.ts    | 4 ++--
 packages/expect/src/utils.ts                   | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/expect/src/__tests__/matchers.test.js b/packages/expect/src/__tests__/matchers.test.js
index 6ee3810c6c61..610f3b8e7d74 100644
--- a/packages/expect/src/__tests__/matchers.test.js
+++ b/packages/expect/src/__tests__/matchers.test.js
@@ -437,7 +437,7 @@ describe('.toStrictEqual()', () => {
     expect(Uint8Array.from([1]).buffer).toStrictEqual(Uint8Array.from([1]).buffer);
     expect(Uint8Array.from([]).buffer).toStrictEqual(Uint8Array.from([]).buffer);
     expect(Uint8Array.from([9,3]).buffer).toStrictEqual(Uint8Array.from([9,3]).buffer);
-  })
+  });
   /* eslint-enable */
 });
 
diff --git a/packages/expect/src/__tests__/utils.test.ts b/packages/expect/src/__tests__/utils.test.ts
index 0d25692dbd02..403eb89fe548 100644
--- a/packages/expect/src/__tests__/utils.test.ts
+++ b/packages/expect/src/__tests__/utils.test.ts
@@ -470,14 +470,14 @@ describe('iterableEquality', () => {
 
 describe('arrayBufferEquality', () => {
   test('returns undefined if given a non instance of ArrayBuffer', () => {
-    expect(arrayBufferEquality(2, "s")).toBeUndefined();
+    expect(arrayBufferEquality(2, 's')).toBeUndefined();
     expect(arrayBufferEquality(undefined, 2)).toBeUndefined();
     expect(arrayBufferEquality(new Date(), new ArrayBuffer(2))).toBeUndefined();
   });
 
   test('returns false when given non-matching buffers', () => {
     const a = Uint8Array.from([2,4]).buffer;
-    const b = Uint8Array.from([1,7]).buffer;
+    const b = Uint16Array.from([1,7]).buffer;
     expect(arrayBufferEquality(a, b)).not.toBeTruthy();
   });
 
diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 6a1c622f2a63..05b515c249a1 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -340,7 +340,7 @@ export const arrayBufferEquality = (a: unknown, b: unknown): boolean | undefined
   }
 
   return true;
-}
+};
 
 export const sparseArrayEquality = (
   a: unknown,

From 20bdbc15c29fbf21bdbf2fdcc793e0d6bcc7c7da Mon Sep 17 00:00:00 2001
From: khai93 <33293519+khai93@users.noreply.github.com>
Date: Wed, 8 Sep 2021 10:06:00 -0500
Subject: [PATCH 13/13] fix eslint errors

---
 .../expect/src/__tests__/matchers.test.js     | 24 ++++++++++++++-----
 packages/expect/src/__tests__/utils.test.ts   | 10 ++++----
 packages/expect/src/utils.ts                  |  7 ++++--
 3 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/packages/expect/src/__tests__/matchers.test.js b/packages/expect/src/__tests__/matchers.test.js
index 610f3b8e7d74..1e244e6d7d57 100644
--- a/packages/expect/src/__tests__/matchers.test.js
+++ b/packages/expect/src/__tests__/matchers.test.js
@@ -428,15 +428,27 @@ describe('.toStrictEqual()', () => {
   });
 
   it('does not pass when ArrayBuffers are not equal', () => {
-    expect(Uint8Array.from([1, 2]).buffer).not.toStrictEqual(Uint8Array.from([0, 0]).buffer);
-    expect(Uint8Array.from([2,1]).buffer).not.toStrictEqual(Uint8Array.from([2,2]).buffer);
-    expect(Uint8Array.from([]).buffer).not.toStrictEqual(Uint8Array.from([1]).buffer);
+    expect(Uint8Array.from([1, 2]).buffer).not.toStrictEqual(
+      Uint8Array.from([0, 0]).buffer,
+    );
+    expect(Uint8Array.from([2, 1]).buffer).not.toStrictEqual(
+      Uint8Array.from([2, 2]).buffer,
+    );
+    expect(Uint8Array.from([]).buffer).not.toStrictEqual(
+      Uint8Array.from([1]).buffer,
+    );
   });
 
   it('passes for matching buffers', () => {
-    expect(Uint8Array.from([1]).buffer).toStrictEqual(Uint8Array.from([1]).buffer);
-    expect(Uint8Array.from([]).buffer).toStrictEqual(Uint8Array.from([]).buffer);
-    expect(Uint8Array.from([9,3]).buffer).toStrictEqual(Uint8Array.from([9,3]).buffer);
+    expect(Uint8Array.from([1]).buffer).toStrictEqual(
+      Uint8Array.from([1]).buffer,
+    );
+    expect(Uint8Array.from([]).buffer).toStrictEqual(
+      Uint8Array.from([]).buffer,
+    );
+    expect(Uint8Array.from([9, 3]).buffer).toStrictEqual(
+      Uint8Array.from([9, 3]).buffer,
+    );
   });
   /* eslint-enable */
 });
diff --git a/packages/expect/src/__tests__/utils.test.ts b/packages/expect/src/__tests__/utils.test.ts
index 403eb89fe548..0654d99a43c2 100644
--- a/packages/expect/src/__tests__/utils.test.ts
+++ b/packages/expect/src/__tests__/utils.test.ts
@@ -476,14 +476,14 @@ describe('arrayBufferEquality', () => {
   });
 
   test('returns false when given non-matching buffers', () => {
-    const a = Uint8Array.from([2,4]).buffer;
-    const b = Uint16Array.from([1,7]).buffer;
+    const a = Uint8Array.from([2, 4]).buffer;
+    const b = Uint16Array.from([1, 7]).buffer;
     expect(arrayBufferEquality(a, b)).not.toBeTruthy();
   });
 
   test('returns true when given matching buffers', () => {
-    const a = Uint8Array.from([1,2]).buffer;
-    const b = Uint8Array.from([1,2]).buffer;
+    const a = Uint8Array.from([1, 2]).buffer;
+    const b = Uint8Array.from([1, 2]).buffer;
     expect(arrayBufferEquality(a, b)).toBeTruthy();
-  })
+  });
 });
diff --git a/packages/expect/src/utils.ts b/packages/expect/src/utils.ts
index 05b515c249a1..eab02cd36204 100644
--- a/packages/expect/src/utils.ts
+++ b/packages/expect/src/utils.ts
@@ -319,7 +319,10 @@ export const typeEquality = (a: any, b: any): boolean | undefined => {
   return false;
 };
 
-export const arrayBufferEquality = (a: unknown, b: unknown): boolean | undefined => {
+export const arrayBufferEquality = (
+  a: unknown,
+  b: unknown,
+): boolean | undefined => {
   if (!(a instanceof ArrayBuffer) || !(b instanceof ArrayBuffer)) {
     return undefined;
   }
@@ -333,7 +336,7 @@ export const arrayBufferEquality = (a: unknown, b: unknown): boolean | undefined
   }
 
   // Check if every byte value is equal to each other
-  for (let i = 0;i < dataViewA.byteLength; i++) {
+  for (let i = 0; i < dataViewA.byteLength; i++) {
     if (dataViewA.getUint8(i) !== dataViewB.getUint8(i)) {
       return false;
     }