Issue #2848808 by voleger, gaurav.kapoor, andypost, Vidushi Mehta, sidharthap:...

Issue #2848808 by voleger, gaurav.kapoor, andypost, Vidushi Mehta, sidharthap: Replace all calls to db_find_tables, which is deprecated

core/includes/database.inc

@@ -721,6 +721,10 @@ function db_field_exists($table, $field) {
  * @see \Drupal\Core\Database\Schema::findTables()
  */
 function db_find_tables($table_expression) {
+  @trigger_error(
+    'db_find_tables() is deprecated in Drupal 8.0.x and will be removed before Drupal 9.0.0. Use $injected_database->schema()->findTables($table_expression) instead. See https://www.drupal.org/node/2993033',
+    E_USER_DEPRECATED
+  );
   return Database::getConnection()->schema()->findTables($table_expression);
 }
 

core/modules/simpletest/simpletest.module

@@ -670,7 +670,7 @@ function simpletest_clean_environment() {
  */
 function simpletest_clean_database() {
   $schema = Database::getConnection()->schema();
-  $tables = db_find_tables('test%');
+  $tables = $schema->findTables('test%');
   $count = 0;
   foreach ($tables as $table) {
     // Only drop tables which begin wih 'test' followed by digits, for example,

core/modules/system/src/Tests/Module/ModuleTestBase.php

@@ -42,7 +42,8 @@ protected function setUp() {
    *   specified base table. Defaults to TRUE.
    */
   public function assertTableCount($base_table, $count = TRUE) {
-    $tables = db_find_tables(Database::getConnection()->prefixTables('{' . $base_table . '}') . '%');
+    $connection = Database::getConnection();
+    $tables = $connection->schema()->findTables($connection->prefixTables('{' . $base_table . '}') . '%');
 
     if ($count) {
       return $this->assertTrue($tables, format_string('Tables matching "@base_table" found.', ['@base_table' => $base_table]));

core/modules/system/tests/src/Functional/Module/ModuleTestBase.php

@@ -39,7 +39,8 @@ protected function setUp() {
    *   specified base table. Defaults to TRUE.
    */
   public function assertTableCount($base_table, $count = TRUE) {
-    $tables = db_find_tables(Database::getConnection()->prefixTables('{' . $base_table . '}') . '%');
+    $connection = Database::getConnection();
+    $tables = $connection->schema()->findTables($connection->prefixTables('{' . $base_table . '}') . '%');
 
     if ($count) {
       return $this->assertTrue($tables, format_string('Tables matching "@base_table" found.', ['@base_table' => $base_table]));

core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php

@@ -71,6 +71,19 @@ public function testDbTableExists() {
     $this->assertTrue(db_table_exists('test'));
   }
 
+  /**
+   * Tests the db_find_tables() function.
+   *
+   * @expectedDeprecation db_find_tables() is deprecated in Drupal 8.0.x and will be removed before Drupal 9.0.0. Use $injected_database->schema()->findTables($table_expression) instead. See https://www.drupal.org/node/2993033
+   */
+  public function testDbFindTables() {
+    $expected = [
+      'test_people' => 'test_people',
+      'test_people_copy' => 'test_people_copy',
+    ];
+    $this->assertEquals($expected, db_find_tables('test_people%'));
+  }
+
   /**
    * Tests the db_set_active() function.
    *