detect early implementations of %TypedArray%.prototype.toSpliced

zloirock · Jun 25, 2022 · cdbd392 · cdbd392
1 parent 1b7d33d
commit cdbd392
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Showing 3 changed files with 37 additions and 3 deletions.
diff --git a/packages/core-js/modules/esnext.typed-array.to-spliced.js b/packages/core-js/modules/esnext.typed-array.to-spliced.js
@@ -6,6 +6,7 @@ var toAbsoluteIndex = require('../internals/to-absolute-index');
 var toBigInt = require('../internals/to-big-int');
 var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
 var uncurryThis = require('../internals/function-uncurry-this');
+var fails = require('../internals/fails');
 
 var aTypedArray = ArrayBufferViewCore.aTypedArray;
 var getTypedArrayConstructor = ArrayBufferViewCore.getTypedArrayConstructor;
@@ -14,6 +15,21 @@ var push = uncurryThis([].push);
 var max = Math.max;
 var min = Math.min;
 
+// some early implementations, like WebKit, does not follow the final semantic
+var PROPER_ORDER = !fails(function () {
+  // eslint-disable-next-line es-x/no-typed-arrays -- required for testing
+  var array = new Int8Array([1]);
+
+  var spliced = array.toSpliced(1, 0, {
+    valueOf: function () {
+      array[0] = 2;
+      return 3;
+    }
+  });
+
+  return spliced[0] !== 2 || spliced[1] !== 3;
+});
+
 // `%TypedArray%.prototype.toSpliced` method
 // https://tc39.es/proposal-change-array-by-copy/#sec-%typedarray%.prototype.toSpliced
 exportTypedArrayMethod('toSpliced', function toSpliced(start, deleteCount /* , ...items */) {
@@ -48,4 +64,4 @@ exportTypedArrayMethod('toSpliced', function toSpliced(start, deleteCount /* , .
   for (; k < newLen; k++) A[k] = O[k + actualDeleteCount - insertCount];
 
   return A;
-});
+}, !PROPER_ORDER);
diff --git a/tests/compat/tests.js b/tests/compat/tests.js
@@ -1714,7 +1714,16 @@ GLOBAL.tests = {
     return Int8Array.prototype.toSorted;
   },
   'esnext.typed-array.to-spliced': function () {
-    return Int8Array.prototype.toSpliced;
+    var array = new Int8Array([1]);
+
+    var spliced = array.toSpliced(1, 0, {
+      valueOf: function () {
+        array[0] = 2;
+        return 3;
+      }
+    });
+
+    return spliced[0] === 2 && spliced[1] === 3;
   },
   'esnext.typed-array.unique-by': function () {
     return Int8Array.prototype.uniqueBy;

diff --git a/tests/tests/esnext.typed-array.to-spliced.js b/tests/tests/esnext.typed-array.to-spliced.js
@@ -11,7 +11,7 @@ if (DESCRIPTORS) QUnit.test('%TypedArrayPrototype%.toSpliced', assert => {
     assert.name(toSpliced, 'toSpliced', `${ name }::toSpliced name is 'toSpliced'`);
     assert.looksNative(toSpliced, `${ name }::toSpliced looks native`);
 
-    const array = new TypedArray([1, 2, 3, 4, 5]);
+    let array = new TypedArray([1, 2, 3, 4, 5]);
     assert.notSame(array.toSpliced(2), array, 'immutable');
 
     assert.deepEqual(new TypedArray([1, 2, 3, 4, 5]).toSpliced(2), new TypedArray([1, 2]));
@@ -20,6 +20,15 @@ if (DESCRIPTORS) QUnit.test('%TypedArrayPrototype%.toSpliced', assert => {
     assert.deepEqual(new TypedArray([1, 2, 3, 4, 5]).toSpliced(2, -2), new TypedArray([1, 2, 3, 4, 5]));
     assert.deepEqual(new TypedArray([1, 2, 3, 4, 5]).toSpliced(2, 2, 6, 7), new TypedArray([1, 2, 6, 7, 5]));
 
+    array = new TypedArray([1]);
+
+    assert.deepEqual(array.toSpliced(1, 0, {
+      valueOf() {
+        array[0] = 2;
+        return 3;
+      },
+    }), new TypedArray([2, 3]), 'operations order');
+
     assert.throws(() => toSpliced.call(null), TypeError, "isn't generic #1");
     assert.throws(() => toSpliced.call(undefined), TypeError, "isn't generic #2");
     assert.throws(() => toSpliced.call([1, 2]), TypeError, "isn't generic #3");