spread-array.js - mozsearch

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load(libdir + "asserts.js");

load(libdir + "iteration.js");

load(libdir + "eqArrayHelper.js");

assertEqArray([...[1, 2, 3]], [1, 2, 3]);

assertEqArray([1, ...[2, 3, 4], 5], [1, 2, 3, 4, 5]);

assertEqArray([1, ...[], 2], [1, 2]);

assertEqArray([1, ...[2, 3], 4, ...[5, 6]], [1, 2, 3, 4, 5, 6]);

assertEqArray([1, ...[], 2], [1, 2]);

assertEqArray([1,, ...[2]], [1,, 2]);

assertEqArray([1,, ...[2],, 3,, 4,], [1,, 2,, 3,, 4,]);

assertEqArray([...[1, 2, 3],,,,], [1, 2, 3,,,,]);

assertEqArray([,,...[1, 2, 3],,,,], [,,1,2,3,,,,]);

assertEqArray([...[1, 2, 3],,,,...[]], [1,2,3,,,,]);

assertEqArray([...[undefined]], [undefined]);

// other iterable objects

assertEqArray([...new Int32Array([1, 2, 3])], [1, 2, 3]);

assertEqArray([..."abc"], ["a", "b", "c"]);

assertEqArray([...[1, 2, 3][Symbol.iterator]()], [1, 2, 3]);

assertEqArray([...new Set([1, 2, 3])], [1, 2, 3]);

assertEqArray([...new Map([["a", "A"], ["b", "B"], ["c", "C"]])].map(([k, v]) => k + v), ["aA", "bB", "cC"]);

let itr = {};

itr[Symbol.iterator] = function () {

    return {

        i: 1,

        next: function() {

            if (this.i < 4)

                return { value: this.i++, done: false };

            else

                return { value: undefined, done: true };

};

assertEqArray([...itr], [1, 2, 3]);

function* gen() {

    for (let i = 1; i < 4; i ++)

        yield i;

assertEqArray([...gen()], [1, 2, 3]);

let a, b = [1, 2, 3];

assertEqArray([...a=b], [1, 2, 3]);

// 12.2.4.1.2 Runtime Semantics: ArrayAccumulation

// If Type(spreadObj) is not Object, then throw a TypeError exception.

assertThrowsInstanceOf(() => [...null], TypeError);

assertThrowsInstanceOf(() => [...undefined], TypeError);