formatter: preserve variadic call arguments#3
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The Go AST stores a call's ellipsis separately from its final argument. Carry that marker through every AST-based call reflow path. This prevents formatting from silently changing variadic-call semantics.
bhandras
marked this pull request as ready for review
July 16, 2026 14:17
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Summary
...when AST-based call reflow rebuilds a variadic callRoot cause
Go stores a call's variadic ellipsis on
ast.CallExpr.Ellipsis, separately from the final expression inast.CallExpr.Args. The affected reflow paths rendered only the argument expressions, so the final slice expression survived while its...marker was omitted.Impact
Formatting now preserves slice expansion semantics instead of silently turning the final expanded slice into an ordinary positional argument.
Testing
make self-checkmake lint