diff --git a/test/built-ins/Array/prototype/groupByToMap/callback-arg.js b/test/built-ins/Array/prototype/groupByToMap/callback-arg.js
new file mode 100644
index 0000000000..d66d21e9e8
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/callback-arg.js
@@ -0,0 +1,35 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap populates Map with correct keys and values
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+  6. Repeat, while k < len
+
+    a. Let Pk be ! ToString(𝔽(k)).
+    b. Let kValue be ? Get(O, Pk).
+    c. Let key be ? Call(callbackfn, thisArg, « kValue, 𝔽(k), O »).
+    d. If key is -0𝔽, set key to +0𝔽.
+    e. Perform ! AddValueToKeyedGroup(groups, key, kValue).
+    f. Set k to k + 1.
+
+  ...
+
+---*/
+
+
+const arr = [-0,0,1,2,3];
+
+const sentinel = {};
+
+const map = arr.groupByToMap.call(sentinel, (n,i,testArr) => {
+    assert.sameValue(this, sentinel, "this value is correctly bound");
+    assert.sameValue(n, arr[i], "selected element aligns with index");
+    assert.sameValue(testArr, arr, "original array is passed as final argument");
+    return null; 
+});
diff --git a/test/built-ins/Array/prototype/groupByToMap/emptyList.js b/test/built-ins/Array/prototype/groupByToMap/emptyList.js
new file mode 100644
index 0000000000..01a7580d60
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/emptyList.js
@@ -0,0 +1,25 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap populates Map with correct keys and values
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+  8. For each Record { [[Key]], [[Elements]] } g of groups, do
+
+    a. Let elements be ! CreateArrayFromList(g.[[Elements]]).
+    b. Let entry be the Record { [[Key]]: g.[[Key]], [[Value]]: elements }.
+    c. Append entry as the last element of map.[[MapData]].
+
+  ...
+
+---*/
+
+const map = [].groupByToMap(i=>i);
+
+assert.sameValue(map.size, 0);
+assert.sameValue(typeof map, typeof new Map());
diff --git a/test/built-ins/Array/prototype/groupByToMap/evenOdd.js b/test/built-ins/Array/prototype/groupByToMap/evenOdd.js
new file mode 100644
index 0000000000..278b6854cb
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/evenOdd.js
@@ -0,0 +1,27 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap populates Map with correct keys and values
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+  8. For each Record { [[Key]], [[Elements]] } g of groups, do
+
+    a. Let elements be ! CreateArrayFromList(g.[[Elements]]).
+    b. Let entry be the Record { [[Key]]: g.[[Key]], [[Value]]: elements }.
+    c. Append entry as the last element of map.[[MapData]].
+
+  ...
+---*/
+
+const array = [1,2,3];
+
+const map = array.groupByToMap(i=>{return i%2===0?'even':'odd';});
+
+assert.sameValue(map.get('even')[0], 2);
+assert.sameValue(map.get('odd')[0], 1);
+assert.sameValue(map.get('odd')[1], 3);
diff --git a/test/built-ins/Array/prototype/groupByToMap/groupByLength.js b/test/built-ins/Array/prototype/groupByToMap/groupByLength.js
new file mode 100644
index 0000000000..c50751242d
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/groupByLength.js
@@ -0,0 +1,28 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap populates Map with correct keys and values
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+  8. For each Record { [[Key]], [[Elements]] } g of groups, do
+
+    a. Let elements be ! CreateArrayFromList(g.[[Elements]]).
+    b. Let entry be the Record { [[Key]]: g.[[Key]], [[Value]]: elements }.
+    c. Append entry as the last element of map.[[MapData]].
+
+  ...
+
+---*/
+
+const arr = ['test', 'hello', 'world'];
+
+const map = arr.groupByToMap(i=>i.length);
+
+assert.sameValue(map.get(4)[0], 'test');
+assert.sameValue(map.get(5)[0], 'hello');
+assert.sameValue(map.get(5)[1], 'world')
diff --git a/test/built-ins/Array/prototype/groupByToMap/length.js b/test/built-ins/Array/prototype/groupByToMap/length.js
new file mode 100644
index 0000000000..876af00d40
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/length.js
@@ -0,0 +1,29 @@
+
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap property length descriptor
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+    17 ECMAScript Standard Built-in Objects
+  
+  ...
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  Array.prototype.groupByToMap.length, 1,
+  'The value of `Array.prototype.groupByMap.length` is `1`'
+);
+  
+verifyProperty(Array.prototype.groupByToMap, "length", {
+  enumerable: false,
+  writable: false,
+  configurable: true
+});
diff --git a/test/built-ins/Array/prototype/groupByToMap/name.js b/test/built-ins/Array/prototype/groupByToMap/name.js
new file mode 100644
index 0000000000..b91ea4e130
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/name.js
@@ -0,0 +1,28 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap property name descriptor
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+    17 ECMAScript Standard Built-in Objects
+  
+  ...
+
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+    Array.prototype.groupByToMap.name, 'groupByToMap',
+    'The value of `Array.prototype.groupByMap.name` is `"groupByMap"`'
+);
+  
+verifyProperty(Array.prototype.groupByToMap, "name", {
+  enumerable: false,
+  writable: false,
+  configurable: true
+});
diff --git a/test/built-ins/Array/prototype/groupByToMap/negativeZero.js b/test/built-ins/Array/prototype/groupByToMap/negativeZero.js
new file mode 100644
index 0000000000..37a00843a4
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/negativeZero.js
@@ -0,0 +1,25 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap normalize 0 for Map key
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+  6.d. If key is -0𝔽, set key to +0𝔽.
+
+  ...
+---*/
+
+
+const arr = [-0, +0];
+
+const map = arr.groupByToMap(i=>i);
+
+
+assert.sameValue(map.size, 1);
+assert.sameValue(map.has(0), true);
+assert.sameValue(map.get(0).length, 2);
diff --git a/test/built-ins/Array/prototype/groupByToMap/null.js b/test/built-ins/Array/prototype/groupByToMap/null.js
new file mode 100644
index 0000000000..f0ae7855dd
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/null.js
@@ -0,0 +1,21 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap applied to null throws a TypeError
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+  3. If IsCallable(callbackfn) is false, throw a TypeError exception.
+
+  ...
+
+---*/
+
+
+assert.throws(TypeError, function() {
+  Array.prototype.groupByToMap.call(null,null);
+});
diff --git a/test/built-ins/Array/prototype/groupByToMap/undefined.js b/test/built-ins/Array/prototype/groupByToMap/undefined.js
new file mode 100644
index 0000000000..0ef5ab313c
--- /dev/null
+++ b/test/built-ins/Array/prototype/groupByToMap/undefined.js
@@ -0,0 +1,21 @@
+// Copyright (c) 2021 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.groupByToMap
+description: Array.prototype.groupByToMap applied to undefined throws a TypeError
+info: |
+  22.1.3.15 Array.prototype.groupByToMap ( callbackfn [ , thisArg ] )
+
+  ...
+
+  3. If IsCallable(callbackfn) is false, throw a TypeError exception.
+
+  ...
+
+---*/
+
+
+assert.throws(TypeError, function() {
+  Array.prototype.groupByToMap.call(undefined, undefined);
+});