Fix issue #217: Wrap FuncCall arguments in parentheses when using :: cast syntax

[pyramation]

Fix #217: Wrap FuncCall arguments in parentheses when using :: cast syntax

Summary

Fixes a bug where double type casts with the :: operator were being deparsed incorrectly due to operator precedence issues. When a FuncCall (like AT TIME ZONE) was cast using the :: shorthand syntax, the cast would bind to the wrong operand.

Example of the bug:

• Input: SELECT CAST(t.date AT TIME ZONE 'America/New_York' AS text)::date FROM tbl t
• Incorrect output: SELECT CAST(t.date AT TIME ZONE 'America/New_York'::text AS date) FROM tbl AS t
  • The ::text was binding to 'America/New_York' instead of the entire CAST(...) expression

The fix:
When using the :: cast shorthand syntax with a FuncCall argument, wrap the FuncCall in parentheses: (t.date AT TIME ZONE 'America/New_York')::text

Changes:

• Modified TypeCast function in packages/deparser/src/deparser.ts (13 lines changed)
• Added test fixture for issue Double CAST Error #217
• Updated pg-catalog snapshot (function calls now wrapped in parens when cast)

Review & Testing Checklist for Human

• Test the original issue: Verify that SELECT CAST(t.date AT TIME ZONE 'America/New_York' AS text)::date FROM tbl t now deparses correctly and can be re-parsed without AST changes (parse → deparse → reparse should produce identical AST)
• Verify simple casts still work: Test that simple casts like '123'::int and '1 day'::interval still work correctly without unnecessary parentheses
• Review the snapshot change: The pg-catalog snapshot shows public.gen_random_uuid()::text now becomes (public.gen_random_uuid())::text. Verify this is correct and doesn't break any downstream consumers

Test Plan

1. Run the deparser test suite: cd packages/deparser && yarn test (all 654 tests should pass ✓)
2. Test the specific issue manually:

   const sql = `SELECT CAST(t.date AT TIME ZONE 'America/New_York' AS text)::date FROM tbl t`;
   const ast = await parse(sql);
   const deparsed = await deparse(ast);
   const reparsed = await parse(deparsed);
   // Verify ast and reparsed are identical

3. Spot check other type casts to ensure no regressions

Notes

• All 654 deparser tests pass locally
• This PR supersedes Fix issue #217: Wrap FuncCall arguments in parentheses when using :: cast syntax #226 which had the same fix but included accidental formatting changes
• The fix is minimal: only 2 files changed, 8 insertions, 3 deletions
• Used TDD approach: test added first (red), then fix applied (green)

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Devin Session: https://app.devin.ai/sessions/111a29019c274f83a61a873f35081622
Requested by: Dan Lynch (@pyramation)

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