Add test helper functions for controlling HTML ID generation

[vjik]

Q	A
Is bugfix?	❌
New feature?	✔️
Breaks BC?	❌

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (3507be6) to head (6c6813a).
⚠️ Report is 3 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##              master      #274   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
- Complexity       828       831    +3     
===========================================
  Files             89        91    +2     
  Lines           2225      2233    +8     
===========================================
+ Hits            2225      2233    +8     

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[Copilot]

Pull request overview

This PR introduces a deterministic testing mechanism for Html::generateId() by extracting the ID-generation logic into an internal IdGenerator and adding opt-in test helper functions to control timestamp seeding and counters. It also updates the PHPUnit bootstrap, documentation, and test suite to use the new approach instead of mocking hrtime().

Changes:

• Add Yiisoft\Html\IdGenerator and refactor Html::generateId() to delegate to it.
• Add src/test-functions.php with enableSeed(), disableSeed(), and reset() helpers for deterministic ID generation in tests.
• Update PHPUnit bootstrap/config, documentation, changelog, and replace the old hrtime() mock-based test with a new dedicated test class.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/mocks/hrtime.php	Removes the old hrtime() mocking approach.
tests/HtmlTest.php	Drops the previous generateId test and associated mock plumbing.
tests/HtmlGenerateIdTest.php	Adds new focused tests covering seeded vs deterministic ID generation and reset behavior.
tests/bootstrap.php	Adds a PHPUnit bootstrap that loads Composer autoload + the new test helper functions.
src/test-functions.php	Introduces test-only helper functions to manipulate IdGenerator state.
src/IdGenerator.php	Adds extracted internal ID generation logic and state.
src/Html.php	Refactors generateId() to use IdGenerator::generate() and updates PHPDoc.
README.md	Links to the new “Testing ID generation” documentation.
phpunit.xml.dist	Switches PHPUnit bootstrap to tests/bootstrap.php.
docs/testing-id-generation.md	Adds documentation describing how to make ID generation deterministic in tests.
CHANGELOG.md	Records the new feature entry for the upcoming release.

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