Solr 7.x compatibility with Moodle search plugin

1. Install a new site
2. Enable global search.
3. Set the following constants in your config.php:

   define('TEST_SEARCH_SOLR_HOSTNAME', 'localhost');

   define('TEST_SEARCH_SOLR_PORT', '8983');

   define('TEST_SEARCH_SOLR_INDEXNAME', 'unittest');

4. Generate phpunit files for moodle components:

   php admin/tool/phpunit/cli/util.php --buildcomponentconfigs

Test 1

1. Using docker, install solr 7 and create an index for your site using the same index name:

   docker run --name solr7 -d -p 8983:8983 -t solr:7

   docker exec -it --user=solr solr7 bin/solr create_core -c YOURINDEXNAME

   docker exec -it --user=solr solr7 bin/solr create_core -c unittest

2. Go to "admin/settings.php?section=searchsolr", set YOURINDEXNAME as 'Index name' and save changes
3. Go to "admin/category.php?category=searchplugins".
4. On 'Setup search engine', you should see "Error validating Solr schema: field itemid does not exist. Please follow this link to set up the required fields.".
5. Click on "follow this link"
6. The process should finish without issues and you should see "Yes" for "Setup search engine"
7. Now click on 'Index data' link and press 'Reindex all site contents'
8. Confirm that search is working in search/index.php (search for 'admin' and admin user will appear as a result)
9. Search component unit tests should pass without any skipped test

   vendor/bin/phpunit -c search

Test 2

1. Stop your solr 7 server.

   docker stop solr7

2. Using docker, install solr 6 and create an index for your site:

   docker run --name solr6 -d -p 8983:8983 -t solr:6

   docker exec -it --user=solr solr6 bin/solr create_core -c ANOTHERINDEXNAME

   docker exec -it --user=solr solr6 bin/solr create_core -c unittest

3. Go to "admin/settings.php?section=searchsolr", set ANOTHERINDEXNAME as 'Index name'.
4. Save the changes
   Note: At this point it is possible that you see a solr client error debugging message; this message appears because the index we configured in test 2 is not available anymore, do not worry about it
5. Go to "admin/category.php?category=searchplugins"
6. On 'Setup search engine', you should see "Error validating Solr schema: field itemid does not exist. Please follow this link to set up the required fields.".
7. Click on "follow this link"
8. The process should finish without issues and you should see "Yes" for "Setup search engine"
9. Now click on 'Index data' link and press 'Reindex all site contents'
10. Confirm that search is working in search/index.php (search for 'admin' and admin user will appear as a result)
11. Search component unit tests should pass without any skipped test

    vendor/bin/phpunit -c search