Add wpdb fallback for wp db query, wp db import, wp db drop, and wp db reset when mysql/mariadb binary is unavailable

features/db-import.feature

@@ -69,6 +69,34 @@ Feature: Import a WordPress database
       Success: Imported from 'wp_cli_test.sql'.
       """
 
+  @require-mysql-or-mariadb
+  Scenario: Database import falls back to wpdb when mysql binary is unavailable
+    Given a WP install
+    And a fake-bin/mysql file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+    And a fake-bin/mariadb file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+
+    When I run `wp db export wp_cli_test.sql`
+    Then the wp_cli_test.sql file should exist
+
+    When I run `chmod +x fake-bin/mysql fake-bin/mariadb`
+    And I try `env PATH={RUN_DIR}/fake-bin:$PATH wp db import wp_cli_test.sql --debug`
+    Then STDOUT should be:
+      """
+      Success: Imported from 'wp_cli_test.sql'.
+      """
+    And STDERR should contain:
+      """
+      MySQL/MariaDB binary not available, falling back to wpdb for import.
+      """
+
   # SQLite doesn't support the --dbuser flag.
   @require-mysql-or-mariadb
   Scenario: Import from database name path by default with passed-in dbuser/dbpass

features/db-query.feature

@@ -119,3 +119,29 @@ Feature: Query the database with WordPress' MySQL config
       """
       ANSI
       """
+
+  @require-mysql-or-mariadb
+  Scenario: Database querying falls back to wpdb when mysql binary is unavailable
+    Given a WP install
+    And a fake-bin/mysql file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+    And a fake-bin/mariadb file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+
+    When I run `chmod +x fake-bin/mysql fake-bin/mariadb`
+    And I try `env PATH={RUN_DIR}/fake-bin:$PATH wp db query "SELECT COUNT(ID) FROM wp_users;" --debug`
+    Then STDOUT should be:
+      """
+      COUNT(ID)
+      1
+      """
+    And STDERR should contain:
+      """
+      MySQL/MariaDB binary not available, falling back to wpdb.
+      """

features/db.feature

@@ -383,8 +383,58 @@ Feature: Perform database operations
       Query succeeded. Rows affected: 1
       """
 
-  @require-sqlite @skip-windows
+  @require-mysql-or-mariadb
+  Scenario: Database drop falls back to wpdb when mysql binary is unavailable
+    Given a WP install
+    And a fake-bin/mysql file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+    And a fake-bin/mariadb file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+
+    When I run `chmod +x fake-bin/mysql fake-bin/mariadb`
+    And I try `env PATH={RUN_DIR}/fake-bin:$PATH wp db drop --yes --debug`
+    Then STDOUT should contain:
+      """
+      Success: Database dropped.
+      """
+    And STDERR should contain:
+      """
+      Query via mysqli:
+      """
+
+  @require-mysql-or-mariadb
+  Scenario: Database reset falls back to wpdb when mysql binary is unavailable
+    Given a WP install
+    And a fake-bin/mysql file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+    And a fake-bin/mariadb file:
+      """
+      #!/bin/sh
+      exit 127
+      """
+
+    When I run `chmod +x fake-bin/mysql fake-bin/mariadb`
+    And I try `env PATH={RUN_DIR}/fake-bin:$PATH wp db reset --yes --debug`
+    Then STDOUT should contain:
+      """
+      Success: Database reset.
+      """
+    And STDERR should contain:
+      """
+      Query via mysqli:
+      """
+
   # Skipped on Windows due to persistent file locking issues when run via Behat.
+  @require-sqlite @skip-windows
   Scenario: SQLite DB CRUD operations
     Given a WP install
     And a session_yes file: