lookbehind.js - mozsearch

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// Copyright 2018 the V8 project authors. All rights reserved.

// This code is governed by the BSD license found in the LICENSE file.

/*---

description: Named groups can be used in conjunction with lookbehind

esid: prod-GroupSpecifier

features: [regexp-named-groups, regexp-lookbehind]

includes: [compareArray.js]

---*/

// Unicode mode

assert.compareArray(["f", "c"], "abcdef".match(/(?<=(?<a>\w){3})f/u));

assert.sameValue("c", "abcdef".match(/(?<=(?<a>\w){3})f/u).groups.a);

assert.sameValue("b", "abcdef".match(/(?<=(?<a>\w){4})f/u).groups.a);

assert.sameValue("a", "abcdef".match(/(?<=(?<a>\w)+)f/u).groups.a);

assert.sameValue(null, "abcdef".match(/(?<=(?<a>\w){6})f/u));

assert.compareArray(["f", ""], "abcdef".match(/((?<=\w{3}))f/u));

assert.compareArray(["f", ""], "abcdef".match(/(?<a>(?<=\w{3}))f/u));

assert.compareArray(["f", undefined], "abcdef".match(/(?<!(?<a>\d){3})f/u));

assert.sameValue(null, "abcdef".match(/(?<!(?<a>\D){3})f/u));

assert.compareArray(["f", undefined], "abcdef".match(/(?<!(?<a>\D){3})f|f/u));

assert.compareArray(["f", undefined], "abcdef".match(/(?<a>(?<!\D{3}))f|f/u));

// Non-Unicode mode

assert.compareArray(["f", "c"], "abcdef".match(/(?<=(?<a>\w){3})f/));

assert.sameValue("c", "abcdef".match(/(?<=(?<a>\w){3})f/).groups.a);

assert.sameValue("b", "abcdef".match(/(?<=(?<a>\w){4})f/).groups.a);

assert.sameValue("a", "abcdef".match(/(?<=(?<a>\w)+)f/).groups.a);

assert.sameValue(null, "abcdef".match(/(?<=(?<a>\w){6})f/));

assert.compareArray(["f", ""], "abcdef".match(/((?<=\w{3}))f/));

assert.compareArray(["f", ""], "abcdef".match(/(?<a>(?<=\w{3}))f/));

assert.compareArray(["f", undefined], "abcdef".match(/(?<!(?<a>\d){3})f/));

assert.sameValue(null, "abcdef".match(/(?<!(?<a>\D){3})f/));

assert.compareArray(["f", undefined], "abcdef".match(/(?<!(?<a>\D){3})f|f/));

assert.compareArray(["f", undefined], "abcdef".match(/(?<a>(?<!\D{3}))f|f/));

// Even within a lookbehind, properties are created in left to right order

assert.compareArray(["fst", "snd"], Object.getOwnPropertyNames(

    /(?<=(?<fst>.)|(?<snd>.))/u.exec("abcd").groups));

reportCompare(0, 0);