#3604 perf(mappers): Pre-build static names dict at init time Pull request opened by edgarrmondragon on <!date^1776373257^{date_short}|2026-04-16T21:00:57Z> The names dict passed to simpleeval contains several entries that never change across records: config, stream_name, original_stream_name, and (optionally) fake. Previously these were assembled from scratch inside _eval on every single property of every record. This commit builds those entries once in init into _static_eval_names and introduces _build_eval_names(record), which copies that base dict and merges only the record-level fields. _eval now calls _build_eval_names instead of performing the inline assembly. The evaluator and faker are also moved before _init_functions_and_schema so _static_eval_names can be fully populated before any transform closure is created. Co-Authored-By: Claude Sonnet 4.6 noreply@anthropic.com Summary by Sourcery Optimize mapper expression evaluation by reusing a pre-built static names dictionary for each record instead of rebuilding it per property. Enhancements: • Pre-compute a static simpleeval names dictionary at mapper initialization and reuse it when evaluating expressions for each record. • Introduce a helper to construct per-record evaluation contexts, separating static and record-specific entries. • Adjust mapper initialization order and type aliases to better support the shared evaluator and names dictionary. meltano/sdk