move db_filename to be private, expose filename with default params

Author: tenderlove

ext/sqlite3/database.c

@@ -840,7 +840,7 @@ void init_sqlite3_database()
   rb_define_method(cSqlite3Database, "busy_handler", busy_handler, -1);
   rb_define_method(cSqlite3Database, "busy_timeout=", set_busy_timeout, 1);
   rb_define_method(cSqlite3Database, "transaction_active?", transaction_active_p, 0);
-  rb_define_method(cSqlite3Database, "db_filename", db_filename, 1);
+  rb_define_private_method(cSqlite3Database, "db_filename", db_filename, 1);
 
 #ifdef HAVE_SQLITE3_LOAD_EXTENSION
   rb_define_method(cSqlite3Database, "load_extension", load_extension, 1);

lib/sqlite3/database.rb

@@ -98,6 +98,13 @@ def prepare sql
       end
     end
 
+    # Returns the filename for the database named +db_name+.  +db_name+ defaults
+    # to "main".  Main return `nil` or an empty string if the database is
+    # temporary or in-memory.
+    def filename db_name = 'main'
+      db_filename db_name
+    end
+
     # Executes the given SQL statement. If additional parameters are given,
     # they are treated as bind variables, and are bound to the placeholders in
     # the query.

test/test_database.rb

@@ -15,10 +15,19 @@ def test_segv
     end
 
     def test_db_filename
-      assert_equal '', @db.db_filename('main')
+      assert_equal '', @db.filename('main')
       tf = Tempfile.new
       @db = SQLite3::Database.new tf.path
-      assert_equal tf.path, @db.db_filename('main')
+      assert_equal tf.path, @db.filename('main')
+    ensure
+      tf.unlink
+    end
+
+    def test_filename
+      assert_equal '', @db.filename
+      tf = Tempfile.new
+      @db = SQLite3::Database.new tf.path
+      assert_equal tf.path, @db.filename
     ensure
       tf.unlink
     end