This CL introduces statement positions before the right-hand side of
comma expressions, in order to align the stepping behavior (and also
generally the breakpoint behavior) around semicolon (;) and comma (,)
separated expressions.
The motivation here is that left-hand sides of comma expressions are
evaluated purely for their side-effects and as such, they aren't
really any different from statements from a developers perspective.
And more importantly, minifiers (like UglifyJS, terser, or esbuild)
by default turn statement expression lists into comma-separated
expressions, thus implicitly changing the stepping behavior in ways
that are difficult to understand for developers.
Doc: http://go/chrome-devtools:comma-stepping-proposal
Demo: https://devtools-dbg-stories.netlify.app/crbug-1370200.html
Video: https://i.imgur.com/5WC03wF.gif
Fixed: chromium:1370200
Change-Id: I38f288d964bc992d1de0dce2ed2becd4220793df
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3934288
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83599}
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