ef2df57aa5
This is a reland of 1fba044154
Chromium expectation tests have been disabled, and will be enabled
Original change's description:
> [destructuring] Elide coercible check for simple keys
>
> Simple object destructuring, such as `let {a,b} = o`, is less efficient
> than the equivalent assignments `let a = o.a; let b = o.b`. This is
> because it does a nil check of `o` before the assignments. However, this
> nil check is not strictly necessary for simple (i.e. non-computed) names,
> as there will be an equivalent nil check on the first access to o in
> `o.a`. For computed names the computation is unfortunately obervable.
>
> So, we can elide the nil check when the first property (if any) of the
> destructuring target is a non-computed name. This messes a bit with our
> error messages, so we re-use the CallPrinter to also find destructuring
> assignment based errors, and fiddle with the error message there. As
> a side-effect, we also get out the object name in the AST, so we can
> output a slightly nicer error message.
>
> Change-Id: Iafa858e27ed771a146cd3ba57903cc73bb46951d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1773254
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63453}
TBR=verwaest@chromium.org
Bug: chromium:999473
Change-Id: Ib0b2e4be433c50521ba1722e1c06b672bfefa405
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1777702
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63477}
6 lines
215 B
Plaintext
6 lines
215 B
Plaintext
*%(basename)s:5: TypeError: Cannot destructure 'undefined' as it is undefined.
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var { [x] : y } = undefined;
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^
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TypeError: Cannot destructure 'undefined' as it is undefined.
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at *%(basename)s:5:5
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