Added a test for Array.prototype.flatMap where mapperFunction throws #4893
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ljharb
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Jan 28, 2026
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do we really not already have a test for this?
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I also found that hard to believe! But we really don't 😄 |
ptomato
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Works for me, but maybe an additional line in the test to check that [].flatMap(() => { throw new Test262Error(); }) does not throw?
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That's a great idea. I've added the test case for the empty array as suggested :) |
ptomato
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Jan 30, 2026
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Hello.
This PR covers the abrupt completion returning case of Array.prototype.flatMap(mapperFunction [ , thisArg]) step 5.
Specifically in this PR, I have set mapperFunction as
x => {throw new Test262Error}, so that FlattenIntoArray returns an abrupt completion in step 4.c.ii.1 where mapperFunction is called.