from_string.js - mozsearch

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/* Any copyright is dedicated to the Public Domain.

 * http://creativecommons.org/licenses/publicdomain/ */

// Array.from on a string iterates over the string.

assertDeepEq(Array.from("test string"),

             ['t', 'e', 's', 't', ' ', 's', 't', 'r', 'i', 'n', 'g']);

// Array.from on a string handles surrogate pairs correctly.

var gclef = "\uD834\uDD1E"; // U+1D11E MUSICAL SYMBOL G CLEF

assertDeepEq(Array.from(gclef), [gclef]);

assertDeepEq(Array.from(gclef + " G"), [gclef, " ", "G"]);

// Array.from on a string calls the @@iterator method.

String.prototype[Symbol.iterator] = function* () { yield 1; yield 2; };

assertDeepEq(Array.from("anything"), [1, 2]);

// If the iterator method is deleted, Strings are still arraylike.

delete String.prototype[Symbol.iterator];

assertDeepEq(Array.from("works"), ['w', 'o', 'r', 'k', 's']);

assertDeepEq(Array.from(gclef), ['\uD834', '\uDD1E']);

if (typeof reportCompare === 'function')

    reportCompare(0, 0);