Tests: add unit test coverage for ElasticPressIo and ElasticPressIoTemplateManager

[noruzzamans]

Summary

This PR introduces comprehensive automated unit test coverage for ElasticPressIo and the ElasticPressIoTemplateManager trait in 10up/ElasticPress.

These components manage the lifecycle of ElasticPress.io search template registration, remote template synchronization, service availability checks, and caching. Prior to this PR, neither component had dedicated unit tests in tests/php/.

This PR is 100% test-only and introduces zero production code changes, ensuring zero risk of regressions while significantly strengthening the test harness.

Changes

1. tests/php/TestElasticPressIo.php (New File)

Dedicated unit test suite for ElasticPress\ElasticPressIo:

• test_non_epio_environment_returns_empty():
  • Sets IS_EPIO_ENVIRONMENT=0 to simulate a non-ElasticPress.io environment.
  • Verifies that get_endpoint_status(), get_endpoint_messages(), and get_endpoint_available_services() safely return empty arrays ([]).
  • Verifies that is_service_available('synonyms') returns false without making any unexpected HTTP requests.
• test_get_endpoint_status_from_transient():
  • Sets IS_EPIO_ENVIRONMENT=1 and seeds set_transient( ElasticPressIo::STATUS_TRANSIENT_NAME, ... ) with structured endpoint responses (operational messages, available services with boolean and string flags).
  • Verifies that status, messages, and available services are accurately deserialized from transient cache.
  • Verifies is_service_available() logic across multiple scenarios: active services return true, explicitly disabled services return false, empty string flags return false, and non-existent services return false.

2. tests/php/TestElasticPressIoTemplateManager.php (New File)

Dedicated unit test suite for the ElasticPress\ElasticPressIoTemplateManager trait using an anonymous class test double:

• test_get_hook_prefix():
  • Verifies that get_hook_prefix() correctly converts hyphenated feature slugs into underscore-delimited WordPress hook prefixes (e.g. test-feature-slug -> ep_test_feature_slug, woocommerce-orders-autosuggest -> ep_woocommerce_orders_autosuggest).
• test_epio_save_search_template():
  • Verifies that epio_save_search_template() triggers the {hook_prefix}_template_saved action hook and passes the exact search template JSON body.
• test_epio_delete_search_template():
  • Verifies that epio_delete_search_template() triggers the {hook_prefix}_template_deleted action hook upon template deletion.
• test_epio_get_search_template():
  • Case 1 (Remote Error): Intercepts the request using ep_intercept_remote_request / ep_do_intercept_request to simulate a WP_Error and verifies that epio_get_search_template() safely bubbles up the WP_Error.
  • Case 2 (Success): Simulates an HTTP 200 response with a JSON payload and verifies that the retrieved template body is returned intact.
• test_after_update_feature():
  • Verifies feature slug isolation: feature update events for mismatched slugs do not trigger any save or delete actions.
  • Verifies that activating the feature (['active' => true]) calls epio_save_search_template() and fires the save hook.
  • Verifies that deactivating the feature (['active' => false]) calls epio_delete_search_template() and fires the delete hook.

Testing

1. PHPUnit Execution

./vendor/bin/phpunit tests/php/TestElasticPressIo.php
./vendor/bin/phpunit tests/php/TestElasticPressIoTemplateManager.php

Result: All 7 tests and 25 assertions pass (OK (7 tests, 25 assertions) in < 0.15s).

2. Coding Standards (10up PHPCS Standard)

./vendor/bin/phpcs tests/php/TestElasticPressIo.php tests/php/TestElasticPressIoTemplateManager.php

Result: 0 errors, 0 warnings (100% compliant with 10up PHPCS standards).