replace escape-string-regexp with tiny-escape

[ofershap]

PR Checklist

• Addresses an existing open issue: fixes 🛠️ Repo: replace escape-string-regexp with tiny-escape #5773
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Note: #5746 is a Renovate bot PR to bump escape-string-regexp to v5, which can't land because v5 is ESM-only. This PR offers an alternative path that doesn't need the label.

Overview

escape-string-regexp v5 is ESM-only, so the Renovate PR to upgrade from v4 (#5746) can't land while mocha is still CommonJS (#5400).

tiny-escape has the same API and ships both ESM and CJS. 192 bytes gzipped, zero deps, TypeScript types included.

This unblocks the upgrade without waiting for the CJS-to-ESM migration.

All tests pass (lint, test-node, test-browser).

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: ofershap / name: Ofer Shapira (b880931)

[github-actions]

👋 Hi @ofershap, thanks for the pull request! A scan flagged a concern with it. Could you please take a look?

[pr-task-completion] This PR's body is missing [x] checks on the following tasks from the PR template.

• That issue was marked as status: accepting prs

Repositories often provide a set of tasks that pull request authors are expected to complete. Those tasks should be marked as completed with a [x] in the pull request description. Please complete those tasks and mark the checks as [x] completed.

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[mark-wiemer]

@ofershap ESM-only is not a blocker for us. Mocha's main branch is for v12 and supports Node 20.19.0+, which allows us to require ESM modules. That said, always open to switching to smaller dependencies :) I'll create a backing issue for deeper conversation and link this PR to it :)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.74%. Comparing base (5905ed9) to head (b880931).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5772   +/-   ##
=======================================
  Coverage   88.74%   88.74%           
=======================================
  Files          66       66           
  Lines        4744     4744           
  Branches      976      976           
=======================================
  Hits         4210     4210           
  Misses        534      534           

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[roman-psc]

Once mocha becomes Node >= 24, RegExp.escape can be used

[JoshuaKGoldberg]

Closing out as #5773 is wontfix. Thanks for thinking of us!