Skip RectorCheaperGuardsFirstRule when anchor is not hoist-safe - #281
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Only flag a cheap guard for hoisting when the expensive-call anchor merely captures the value (assignment) or bails on it (pure bail guard). An anchor with its own side effects - an attribute-writing block, or a bare call statement that mutates a variable by-reference inside a closure - is unsafe to hoist past, since the nodes the guard bails out on would lose that side effect. Fixes false positives on DowngradeSubstrFalsyRector and TypeWillReturnCallableArrowFunctionRector. Claude-Session: https://claude.ai/code/session_01Na4eYvNqa2pdhZrBXbegrv
This was referenced Aug 29, 2026
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RectorCheaperGuardsFirstRule(added in 14.13.0) produced false positives on rules where the cheap guard cannot be hoisted above the expensive call:DowngradeSubstrFalsyRectormarkingIS_FALSY_UNCASTABLEon non-substr call args);TypeWillReturnCallableArrowFunctionRectorwith$hasChanged).Fix: only flag when the anchor is genuinely hoist-safe - either an assignment that just captures the expensive value, or a pure bail guard whose condition holds the expensive call. Anything else is skipped.
Adds two skip fixtures reproducing both patterns; the true-positive fixture still reports. Verified against the real rector-downgrade-php and rector-phpunit files: both pass with no ignore needed.