use connection_string as database configuration instead of a hash

spec/std/db/db_spec.cr

@@ -7,16 +7,15 @@ describe DB do
     DB.driver_class("dummy").should eq(DummyDriver)
   end
 
-  it "should instantiate driver with options" do
-    db = DB.open "dummy", {"host": "localhost", "port": "1027"}
+  it "should instantiate driver with connection_string" do
+    db = DB.open "dummy", "localhost:1027"
     db.driver_class.should eq(DummyDriver)
-    db.options["host"].should eq("localhost")
-    db.options["port"].should eq("1027")
+    db.connection_string.should eq("localhost:1027")
   end
 
   it "should create a connection and close it" do
     cnn = nil
-    DB.open "dummy", {"host": "localhost"} do |db|
+    DB.open "dummy", "localhost" do |db|
       cnn = db.connection
     end
 

spec/std/db/dummy_driver.cr

@@ -2,7 +2,7 @@ require "spec"
 
 class DummyDriver < DB::Driver
   def build_connection
-    DummyConnection.new(options)
+    DummyConnection.new(connection_string)
   end
 
   class DummyConnection < DB::Connection
@@ -152,7 +152,7 @@ def with_witness(count = 1)
 end
 
 def with_dummy
-  DB.open "dummy", {} of String => String do |db|
+  DB.open "dummy", "" do |db|
     yield db
   end
 end

src/db/connection.cr

@@ -1,8 +1,8 @@
 module DB
   abstract class Connection
-    getter options
+    getter connection_string
 
-    def initialize(@options)
+    def initialize(@connection_string)
       @closed = false
     end
 

src/db/database.cr

@@ -6,10 +6,10 @@ module DB
   # It should be created from DB module. See `DB.open`.
   class Database
     getter driver_class
-    getter options
+    getter connection_string
 
-    def initialize(@driver_class, @options)
-      @driver = @driver_class.new(@options)
+    def initialize(@driver_class, @connection_string)
+      @driver = @driver_class.new(@connection_string)
       @connection = @driver.build_connection
     end
 

src/db/db.cr

@@ -12,12 +12,12 @@ module DB
     @@drivers.not_nil![name] = klass
   end
 
-  def self.open(name, options)
-    Database.new(driver_class(name), options)
+  def self.open(name, connection_string)
+    Database.new(driver_class(name), connection_string)
   end
 
-  def self.open(name, options, &block)
-    open(name, options).tap do |db|
+  def self.open(name, connection_string, &block)
+    open(name, connection_string).tap do |db|
       yield db
       db.close
     end

src/db/driver.cr

@@ -1,8 +1,8 @@
 module DB
   abstract class Driver
-    getter options
+    getter connection_string
 
-    def initialize(@options)
+    def initialize(@connection_string : String)
     end
 
     abstract def build_connection : Connection