Support DB_PATH for SQLite database commands

features/db-sqlite-path.feature

@@ -0,0 +1,62 @@
+@require-sqlite
+Feature: Select the configured SQLite database for file operations
+
+  Scenario Outline: Use the effective database path without changing another database
+    Given a WP install
+    When I run `wp eval 'copy( defined( "DB_PATH" ) ? DB_PATH : FQDB, "selected.sqlite" ); copy( "selected.sqlite", "other.sqlite" );'`
+    And I run `sqlite3 selected.sqlite "CREATE TABLE path_marker (value TEXT); INSERT INTO path_marker VALUES ('selected');"`
+    And I run `sqlite3 other.sqlite "CREATE TABLE path_marker (value TEXT); INSERT INTO path_marker VALUES ('other');"`
+
+    Given a paths.php file:
+      """
+      <?php
+      if ( '' !== '<db_path>' ) {
+          define( 'DB_PATH', __DIR__ . '/<db_path>' );
+      }
+      if ( '' !== '<fqdb>' ) {
+          define( 'FQDB', __DIR__ . '/<fqdb>' );
+      }
+      if ( '' !== '<db_dir>' ) {
+          define( 'DB_DIR', __DIR__ . '/<db_dir>' );
+      }
+      if ( '' !== '<db_file>' ) {
+          define( 'DB_FILE', '<db_file>' );
+      }
+      if ( '' !== '<fqdbdir>' ) {
+          define( 'FQDBDIR', __DIR__ . '/<fqdbdir>' );
+      }
+      """
+    When I run `wp config set path_constants "require __DIR__ . '/paths.php'" --type=variable --raw`
+    And I try `wp eval 'echo "ready";'`
+    Then the return code should be 0
+
+    When I run `php -r 'echo md5_file( "other.sqlite" );'`
+    Then save STDOUT as {OTHER_HASH}
+
+    When I try `wp db export selected.sql`
+    Then the return code should be 0
+    And the selected.sql file should contain:
+      """
+      INSERT INTO path_marker VALUES('selected');
+      """
+    And the selected.sql file should not contain:
+      """
+      INSERT INTO path_marker VALUES('other');
+      """
+
+    When I try `wp db drop --yes`
+    Then the return code should be 0
+    And the selected.sqlite file should not exist
+
+    When I run `php -r 'echo md5_file( "other.sqlite" );'`
+    Then STDOUT should be:
+      """
+      {OTHER_HASH}
+      """
+
+    Examples:
+      | db_path         | fqdb            | db_dir | db_file         | fqdbdir |
+      | selected.sqlite | other.sqlite    | other  | other.sqlite    | other/  |
+      | selected.sqlite | selected.sqlite | /      | selected.sqlite | /       |
+      |                 | selected.sqlite |        |                 |         |
+      |                 |                 |        | selected.sqlite | /       |

src/DB_Command_SQLite.php

@@ -63,6 +63,10 @@ protected function is_sqlite() {
 	 * @return string|false Path to SQLite database file, or false if not found.
 	 */
 	protected function get_sqlite_db_path() {
+		if ( defined( 'DB_PATH' ) ) {
+			return DB_PATH;
+		}
+
 		// Check for FQDB constant (fully qualified database path).
 		if ( defined( 'FQDB' ) ) {
 			return FQDB;