[react-compiler] Fix GeneratedSource Symbol leaking into output Babel AST loc#36477
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MD-Mushfiqur123 wants to merge 1 commit into
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[react-compiler] Fix GeneratedSource Symbol leaking into output Babel AST loc#36477MD-Mushfiqur123 wants to merge 1 commit into
MD-Mushfiqur123 wants to merge 1 commit into
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babel-plugin-react-compiler uses a Symbol() sentinel (GeneratedSource) for synthesized nodes without source locations. In codegenPlace(), the sentinel was being directly assigned to the output Babel AST node's loc field via an unchecked cast. This violates Babel's Node.loc contract (SourceLocation | null) and causes v8.serialize() to throw when downstream tools try to serialize the compiled AST across worker/process boundaries. The fix adds a guard to only set loc when it is not GeneratedSource, matching the existing pattern used by withLoc() and createCallExpression() in the same file.
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Summary
Fixes #36327
\�abel-plugin-react-compiler\ uses a \Symbol()\ sentinel (\GeneratedSource) for synthesized AST nodes that lack source locations. In \codegenPlace(), this sentinel was being directly assigned to the output Babel AST node's \loc\ field via an unchecked cast (\identifier.loc = place.loc as any).
This violates Babel's \Node.loc\ type contract (\SourceLocation | null) and causes \�8.serialize()\ to throw \Symbol() could not be cloned\ when downstream tools (Metro, Expo, jest-worker, etc.) try to serialize the compiled AST across process/worker boundaries.
Root Cause
In \codegenPlace(), \convertIdentifier()\ correctly skips setting \loc\ when the value is \GeneratedSource\ (via the \withLoc\ wrapper). However, the next line unconditionally overwrites \identifier.loc\ with \place.loc:
\\ ypescript
// Before (broken):
const identifier = convertIdentifier(place.identifier);
identifier.loc = place.loc as any; // leaks Symbol() into output AST
return identifier;
\\
Fix
Added the same guard pattern used by \withLoc()\ and \createCallExpression()\ in the same file:
\\ ypescript
// After (fixed):
const identifier = convertIdentifier(place.identifier);
if (place.loc != null && place.loc !== GeneratedSource) {
identifier.loc = place.loc as any;
}
return identifier;
\\
Test Plan