Address `Panics` in `boa_engine`

[nekevss]

Related to #3235.

With Rust v1.72, clippy began linting any panics that have missing panics documentation.

Some potential approaches to addressing the panics are: remove the panics and update them to return a RuntimeError/ImplementationError or add the documentation to the function that identified as panicking, or a combination of the two of those.

#3235 disables the lint, but the panics should be addressed and the lint reenables.

[jedel1043]

Seeing that some language engines such as Rhai have a Don't Panic guarantee as a feature, maybe we should consider migrating to an ImplementationError as you've said, instead of panicking everywhere.

[KaustubhOG]

Hey @jedel1043! I've started working on this issue with PR #4793 as a first step.

My approach for this issue:

• For panics that enforce internal invariants (where the panic condition is already
  validated upstream), add # Panics documentation explaining when and why they occur
• For panics that could reasonably be replaced with proper error returns, migrate them
  to return JsResult / JsNativeError instead

Starting small with src/error/mod.rs to get feedback on the pattern before scaling
to the rest of the codebase. Happy to adjust the approach based on your guidance!

----//this was old approach (incorrect), new approach is in process

[KaustubhOG]

Hey @jedel1043! as you suggested i added a varient , before proceeding .

[KaustubhOG]

Tracking progress for converting panics in boa_engine to EngineError::Panic using js_expect (#4828).

Note: The PRs listed below may look messy or unstructured for now don't worry, that's intentional . The comments above (where I noted "this approach is wrong") are also being updated and revised as the approach evolved through discussion with maintainers. Everything will be cleaned up and reorganized into a clear architecture with sections and subsections before this month ends .

Progress so far:

• feat(error): add Panic variant to EngineError #4826 — added Panic variant to EngineError
• fix(jsarray): convert panics to EngineError::Panic using js_expect #4837 — converted jsarray.rs (14 panics)
• fix(jstypedarray): convert panics to EngineError::Panic using js_expect #4844 — converted jstypedarray.rs (26 panics)
• fix(jsdataview): convert panics to EngineError::Panic using js_expect #4842 — converted jsdataview.rs (12 panics)
• fix(jsregexp): convert panics to EngineError::Panic using js_expect #4846 — converted jsregexp.rs (17 panics)
• fix(jsproxy): convert panics to EngineError::Panic using js_expect #4854 — converted jsrproxy.rs (13 panics)
• fix(jspromise): convert panics to EngineError::Panic using js_expect #4875 — converted jsrpromise.rs (23 panics)
• fix(builtins/proxy,json,uri): convert panics to EngineError::Panic using js_expect #4925 — converted builtins/proxy,json,uri (24 panics)
• fix(builtins/regexp,async-generator): convert panics to EngineError::Panic using js_expect #4947 — converted builtins/regexp,async-generator (32 panics)
• fix(builtins/function/mod,function/arguments,function/bound,object/mod): convert panics to EngineError::Panic using js_expect #5001 — converted builtins/function/mod, function/arguments, function/bound, object/mod (29 panics)
• fix(builtins/array,string/mod.rs): convert panics to EngineError::Panic using js_expect #5007 — converted builtins/array/mod, array/from_async, string/mod (29 panics)
• fix(builtins/intl, builtins/promise): convert panics to EngineError::Panic using js_expect #5014 — converted builtins/intl, builtins/promise(26panics)
• fix(builtins/typed_array,iterable,generator,error,bigint,eval): convert panics to EngineError::Panic using js_expect #5045 —converted builtins/typed_array,iterable,generator,error,bigint,eval(47panics)--------->/builtins completed
• fix(object/remaining): convert panics to EngineError::Panic using js_expect #5063 —converted object/remaining (5 panic) ----------------> /object completed
• fix(module/source.rs,namespace.rs,synthetic.rs): convert panics to EngineError::Panic using js_expect #5064 —converted module/source.rs,namespace.rs,synthetic.rs(39panic) -----------> /modules completed
• fix(vm/opcode/define,set,call): convert panics to EngineError::Panic using js_expect #5228 —converted vm/opcode/define,set,call(51panic)
• fix(vm/opcode/push,environment,templates,generator,await,new): convert panics to EngineError::Panic using js_expect #5232 — converted vm/opcode/push,environment,templates,generator,await,new(61panic)
• fix( /remaining): convert panics to EngineError::Panic using js_expect #5267 — converted vm/remaining-------------->vm/ completed

note :also /object /modules is not completed some of onvarients can still be converted (mentioned in 5063 5064)