Data.Int.toStringAs in the upstream Lua FFI can emit n = floor(i), which writes a global and leaks mutable shared state. This change ensures the imported foreign source is normalized to local scope for that assignment in the known toStringAs shape.

• Foreign import patching (targeted)

  • Updated Language.PureScript.Backend.Lua.Linker.Foreign.parseForeignSource to post-process parsed exports.
  • For export key toStringAs, when the value matches the expected Data.Int context (math.floor, table.insert, return function(i)), rewrite the specific assignment n = floor(i) to local n = floor(i).
  • Rewrite preserves original indentation.

• Regression coverage

  • Extended Language.PureScript.Backend.Lua.Linker.Foreign.Spec fixture with a toStringAs export containing the leaking assignment.
  • Updated expected parsed output to assert the localized assignment appears in the emitted expression text.

-- before
n = floor(i)

-- after
local n = floor(i)