Allow use of alternative database interfaces

The CLI tool used as a database interface is now specified and
customisable via ActiveRecord.database_cli.

This specifies the current defaults but allows them to be overridden by
users. It continues to accept array values to allow fallback options.

Author: tsvallender

activerecord/CHANGELOG.md

@@ -1,3 +1,13 @@
+*   Support use of alternative database interfaces via the `database_cli` ActiveRecord configuration option.
+
+    ```ruby
+    Rails.application.configure do
+      config.active_record.database_cli = { postgresql: "pgcli" }
+    end
+    ```
+
+    *T S Vallender*
+
 *   Add support for dumping table inheritance and native partitioning table definitions for PostgeSQL adapter
 
     *Justin Talbott*

activerecord/lib/active_record.rb

@@ -207,6 +207,9 @@ def self.schema_cache_ignored_table?(table_name)
     end
   end
 
+  singleton_class.attr_accessor :database_cli
+  self.database_cli = { postgresql: "psql", mysql: %w[mysql mysql5], sqlite: "sqlite3" }
+
   singleton_class.attr_reader :default_timezone
 
   # Determines whether to use Time.utc (using :utc) or Time.local (using :local) when pulling

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -79,7 +79,7 @@ def dbconsole(config, options = {})
 
           args << config.database
 
-          find_cmd_and_exec(["mysql", "mysql5"], *args)
+          find_cmd_and_exec(ActiveRecord.database_cli[:mysql], *args)
         end
       end
 

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -86,7 +86,7 @@ def dbconsole(config, options = {})
               "-c #{name}=#{value.to_s.gsub(/[ \\]/, '\\\\\0')}" unless value == ":default" || value == :default
             end.join(" ")
           end
-          find_cmd_and_exec("psql", config.database)
+          find_cmd_and_exec(ActiveRecord.database_cli[:postgresql], config.database)
         end
       end
 

activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb

@@ -45,7 +45,7 @@ def dbconsole(config, options = {})
           args << "-header" if options[:header]
           args << File.expand_path(config.database, Rails.respond_to?(:root) ? Rails.root : nil)
 
-          find_cmd_and_exec("sqlite3", *args)
+          find_cmd_and_exec(ActiveRecord.database_cli[:sqlite], *args)
         end
       end
 

activerecord/test/cases/adapters/mysql2/dbconsole_test.rb

@@ -63,6 +63,17 @@ def test_mysql_include_password
         end
       end
 
+      def test_mysql_can_use_alternative_cli
+        ActiveRecord.database_cli[:mysql] = "mycli"
+        config = make_db_config(adapter: "mysql2", database: "db", database_cli: "mycli")
+
+        assert_find_cmd_and_exec_called_with(["mycli", "db"]) do
+          Mysql2Adapter.dbconsole(config)
+        end
+      ensure
+        ActiveRecord.database_cli[:mysql] = %w[mysql mysql5]
+      end
+
       private
         def make_db_config(config)
           ActiveRecord::DatabaseConfigurations::HashConfig.new("test", "primary", config)

activerecord/test/cases/adapters/postgresql/dbconsole_test.rb

@@ -78,6 +78,17 @@ def test_postgresql_include_variables
         assert_equal "-c search_path=my_schema,\\ default,\\ \\\\my_schema -c statement_timeout=5000", ENV["PGOPTIONS"]
       end
 
+      def test_postgresql_can_use_alternative_cli
+        ActiveRecord.database_cli[:postgresql] = "pgcli"
+        config = make_db_config(adapter: "postgresql", database: "db")
+
+        assert_find_cmd_and_exec_called_with(["pgcli", "db"]) do
+          PostgreSQLAdapter.dbconsole(config)
+        end
+      ensure
+        ActiveRecord.database_cli[:postgresql] = "psql"
+      end
+
       private
         def preserve_pg_env
           old_values = ENV_VARS.map { |var| ENV[var] }

activerecord/test/cases/adapters/sqlite3/dbconsole_test.rb

@@ -52,6 +52,17 @@ def test_sqlite3_db_with_defined_rails_root
         Rails.singleton_class.remove_method(:root)
       end
 
+      def test_sqlite3_can_use_alternative_cli
+        ActiveRecord.database_cli[:sqlite] = "sqlitecli"
+        config = make_db_config(adapter: "sqlite3", database: "config/db.sqlite3", database_cli: "sqlitecli")
+
+        assert_find_cmd_and_exec_called_with(["sqlitecli", root.join("config/db.sqlite3").to_s]) do
+          SQLite3Adapter.dbconsole(config)
+        end
+      ensure
+        ActiveRecord.database_cli[:sqlite] = "sqlite3"
+      end
+
       private
         def root
           Pathname(__dir__).join("../../../..")

guides/source/configuring.md

@@ -1633,6 +1633,19 @@ warning, or neither.
 | --------------------- | -------------------- |
 | (original)            | `true`               |
 
+#### config.active_record.database_cli
+
+Controls which CLI tool will be used for accessing the database when running `rails dbconsole`. By default
+the standard tool for the database will be used (e.g. `psql` for PostgreSQL and `mysql` for MySQL). The option
+takes a hash which specifies the tool per-database system, and an array can be used where fallback options are
+required:
+
+```ruby
+# config/application.rb
+
+config.active_record.database_cli = { postgresql: "pgcli", mysql: %w[ mycli mysql ] }
+```
+
 #### `ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans` and `ActiveRecord::ConnectionAdapters::TrilogyAdapter.emulate_booleans`
 
 Controls whether the Active Record MySQL adapter will consider all `tinyint(1)` columns as booleans. Defaults to `true`.