Description

The WASM-sandboxed JS runtime does not support stderr or top-level error propagation. We should find a way to emulate these behaviors (or a different JS runtime).

Desired behavior/Acceptance criteria (returned value, expected error, performance expectations, etc.)

• error information can be propagated to the service layer from the WASM JS executor
• there are tests in javascript-all-wasm-test.js that exercise the case of an explicitly-thrown Error (e.g., within a user-supplied implementation)
• there are tests in javascript-all-wasm-test.js that exercise the case of an unintentional Error (syntax error in an implementation, syntax error in a custom serializer, ...)

Completion checklist

• Before closing this task, review one by one the checklist available here: https://www.mediawiki.org/wiki/Abstract_Wikipedia_team/Definition_of_Done#Back-end_Task/Bug_completion_checklist