fix(linter): add help text to eslint rule diagnostics

[shtse8]

Summary

Fixes #19121

Adds actionable .with_help() messages to 8 eslint linter rules that were missing them, as requested in #19121.

Changes

Rule	Help message added
no_eval	Suggest JSON.parse() and bracket notation as alternatives to eval()
no_await_in_loop	Suggest Promise.all() for parallel async execution
no_case_declarations	Suggest wrapping the case body in braces {} to create explicit block scope
no_constructor_return	Clarify that a bare return; is allowed for early exit
no_delete_var	Suggest assigning undefined instead of using delete on variables
no_lone_blocks	Suggest removing unnecessary / redundant block statements (both diagnostics)
require_yield	Suggest adding a yield expression or converting to a regular function
no_const_assign	Suggest using let when a variable needs to be reassigned

All help messages are actionable — they tell the user what to do to fix the issue.

[Copilot]

Pull request overview

Adds actionable help text to previously “message-only” ESLint rule diagnostics in oxc_linter, aligning with #19121’s goal of making lints easier to fix.

Changes:

• Added .with_help(...) guidance to diagnostics for 8 ESLint rules (across 7 files).
• Expanded several diagnostics from single-line chains into multi-line builder chains to include help text.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/oxc_linter/src/rules/eslint/require_yield.rs	Adds help suggesting adding yield or converting to a non-generator function.
crates/oxc_linter/src/rules/eslint/no_lone_blocks.rs	Adds help text for both “unnecessary block” and “redundant nested block” diagnostics.
crates/oxc_linter/src/rules/eslint/no_eval.rs	Adds help with safer alternatives to eval().
crates/oxc_linter/src/rules/eslint/no_delete_var.rs	Adds help explaining delete is for object properties and suggests an alternative.
crates/oxc_linter/src/rules/eslint/no_constructor_return.rs	Adds help clarifying that return; (no value) is allowed for early exit.
crates/oxc_linter/src/rules/eslint/no_const_assign.rs	Adds help recommending let when reassignment is intended.
crates/oxc_linter/src/rules/eslint/no_case_declarations.rs	Adds help recommending {} to introduce explicit block scope within case bodies.

[camc314]

Thank you!

[codspeed-hq]

Merging this PR will not alter performance

✅ 47 untouched benchmarks
⏩ 3 skipped benchmarks¹

---

_{Comparing shtse8:fix/add-help-to-linter-diagnostics (6a59ed6) with main (79fc6d7)}

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩