move spec and src files to a shardy way

spec/db_spec.cr

@@ -0,0 +1,84 @@
+require "./spec_helper"
+
+private def connections
+  DummyDriver::DummyConnection.connections
+end
+
+describe DB do
+  it "should get driver class by name" do
+    DB.driver_class("dummy").should eq(DummyDriver)
+  end
+
+  it "should instantiate driver with connection uri" do
+    db = DB.open "dummy://localhost:1027"
+    db.driver.should be_a(DummyDriver)
+    db.uri.scheme.should eq("dummy")
+    db.uri.host.should eq("localhost")
+    db.uri.port.should eq(1027)
+  end
+
+  it "should create a connection and close it" do
+    DummyDriver::DummyConnection.clear_connections
+    DB.open "dummy://localhost" do |db|
+    end
+    connections.size.should eq(1)
+    connections.first.closed?.should be_true
+  end
+
+  it "query should close result_set" do
+    with_witness do |w|
+      with_dummy do |db|
+        db.query "1,2" do
+          break
+        end
+
+        w.check
+        DummyDriver::DummyResultSet.last_result_set.closed?.should be_true
+      end
+    end
+  end
+
+  it "scalar should close statement" do
+    with_dummy do |db|
+      db.scalar "1"
+      DummyDriver::DummyResultSet.last_result_set.closed?.should be_true
+    end
+  end
+
+  it "initially a single connection should be created" do
+    with_dummy do |db|
+      connections.size.should eq(1)
+    end
+  end
+
+  it "the connection should be closed after db usage" do
+    with_dummy do |db|
+      connections.first.closed?.should be_false
+    end
+    connections.first.closed?.should be_true
+  end
+
+  it "should raise if the sole connection is been used" do
+    with_dummy do |db|
+      db.query "1" do |rs|
+        expect_raises Exception, /DB Pool Exhausted/ do
+          db.scalar "2"
+        end
+      end
+    end
+  end
+
+  it "exec should return to pool" do
+    with_dummy do |db|
+      db.exec "foo"
+      db.exec "bar"
+    end
+  end
+
+  it "scalar should return to pool" do
+    with_dummy do |db|
+      db.scalar "foo"
+      db.scalar "bar"
+    end
+  end
+end