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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /js/src/tests/non262/Array/from_constructor.js | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/tests/non262/Array/from_constructor.js')
-rw-r--r-- | js/src/tests/non262/Array/from_constructor.js | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/js/src/tests/non262/Array/from_constructor.js b/js/src/tests/non262/Array/from_constructor.js new file mode 100644 index 0000000000..6846ef09aa --- /dev/null +++ b/js/src/tests/non262/Array/from_constructor.js @@ -0,0 +1,56 @@ +/* Any copyright is dedicated to the Public Domain. + * http://creativecommons.org/licenses/publicdomain/ */ + +// Array.from can be applied to any constructor. +// For example, the Date builtin constructor. +var d = Array.from.call(Date, ["A", "B"]); +assertEq(Array.isArray(d), false); +assertEq(Object.prototype.toString.call(d), "[object Date]"); +assertEq(Object.getPrototypeOf(d), Date.prototype); +assertEq(d.length, 2); +assertEq(d[0], "A"); +assertEq(d[1], "B"); + +// Or Object. +var obj = Array.from.call(Object, []); +assertEq(Array.isArray(obj), false); +assertEq(Object.getPrototypeOf(obj), Object.prototype); +assertEq(Object.getOwnPropertyNames(obj).join(","), "length"); +assertEq(obj.length, 0); + +// Or any JS function. +function C(arg) { + this.args = arguments; +} +var c = Array.from.call(C, {length: 1, 0: "zero"}); +assertEq(c instanceof C, true); +assertEq(c.args.length, 1); +assertEq(c.args[0], 1); +assertEq(c.length, 1); +assertEq(c[0], "zero"); + +// If the 'this' value passed to Array.from is not a constructor, +// a plain Array is created. +var arr = [3, 4, 5]; +var nonconstructors = [ + {}, Math, Object.getPrototypeOf, undefined, 17, + () => ({}) // arrow functions are not constructors +]; +for (var v of nonconstructors) { + obj = Array.from.call(v, arr); + assertEq(Array.isArray(obj), true); + assertDeepEq(obj, arr); +} + +// Array.from does not get confused if global.Array is replaced with another +// constructor. +function NotArray() { +} +var RealArray = Array; +NotArray.from = Array.from; +Array = NotArray; +assertEq(RealArray.from([1]) instanceof RealArray, true); +assertEq(NotArray.from([1]) instanceof NotArray, true); + +if (typeof reportCompare === 'function') + reportCompare(0, 0); |