Every mode (src/index.js, src/full.js, src/lite.js, src/json.js) picked its clone strategy from Object.prototype.toString.call(x), which reads a user-settable Symbol.toStringTag. A plain object declaring a recognized tag (eg "Map") was routed into that type's clone branch and crashed on methods it doesn't have; one with an unrecognized tag fell through every branch and was returned by reference instead of cloned. Also check the object's real constructor, which Symbol.toStringTag cannot affect, so a plain object (or one with no prototype) is still deep-cloned as a plain object no matter what tag it claims. Fixes #54
43 lines
1.5 KiB
JavaScript
43 lines
1.5 KiB
JavaScript
import { suite } from 'uvu';
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import * as assert from 'assert';
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export default function (klona) {
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const Spoofed = suite('Symbol.toStringTag spoofing');
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// A `Symbol.toStringTag` klona special-cases (eg "Map") used to misroute a
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// plain object into that branch and crash.
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// @see https://github.com/lukeed/klona/issues/54
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Spoofed('recognized tag :: plain object is cloned, not misrouted', () => {
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const input = { a: 1, b: { c: 2 }, [Symbol.toStringTag]: 'Map' };
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const output = klona(input);
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assert.notEqual(output, input, 'must return a new object, not the input');
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assert.equal(output.a, 1);
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assert.deepEqual(output.b, { c: 2 });
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output.a = 999;
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output.b.c = 888;
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assert.equal(input.a, 1, 'mutating output.a must not affect input');
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assert.equal(input.b.c, 2, 'mutating output.b must not affect input');
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});
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// An unrecognized `Symbol.toStringTag` used to fall through every branch
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// and be returned by reference instead of cloned.
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// @see https://github.com/lukeed/klona/issues/54
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Spoofed('unrecognized tag :: plain object is cloned, not returned by reference', () => {
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const input = { a: 1, b: { c: 2 }, [Symbol.toStringTag]: 'Foobar' };
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const output = klona(input);
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assert.notEqual(output, input, 'must return a new object, not the input');
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assert.equal(output.a, 1);
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assert.deepEqual(output.b, { c: 2 });
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output.a = 999;
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output.b.c = 888;
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assert.equal(input.a, 1, 'mutating output.a must not affect input');
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assert.equal(input.b.c, 2, 'mutating output.b must not affect input');
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});
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Spoofed.run();
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}
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