Add spec about connection pool

spec/sql/connection_pool_spec.cr

@@ -0,0 +1,51 @@
+require "../spec_helper"
+
+module ConnectionPoolSpec
+  extend self
+
+  @@count = 0_i64
+
+  def self.reinit
+    reinit_migration_manager
+  end
+
+  describe "Clear::SQL" do
+    describe "ConnectionPool" do
+      it "can handle multiple fibers" do
+
+        begin
+          Clear::SQL.execute("CREATE TABLE tests (id serial PRIMARY KEY)")
+
+          init = true
+          spawn do
+            Clear::SQL.transaction do
+              Clear::SQL.insert("tests", {id: 1}).execute
+              sleep 0.2 #< The transaction is not yet commited
+            end
+          end
+
+          @@count = 0
+
+          spawn do
+            # Not inside the transaction so count must be zero since the transaction is not finished:
+            sleep 0.1
+            @@count = Clear::SQL.select.from("tests").count
+          end
+
+          sleep 0.3 # Let the 2 spawn finish...
+
+          @@count.should eq 0 #< If one, the connection pool got wrong with the fiber.
+
+          # Now the transaction is over, count should be 1
+          count = Clear::SQL.select.from("tests").count
+          count.should eq 1
+      ensure
+          Clear::SQL.execute("DROP TABLE tests;") unless init
+        end
+
+      end
+    end
+  end
+
+
+end

src/clear/sql/logger.cr

@@ -55,7 +55,7 @@ module Clear::SQL::Logger
     o = yield
     elapsed_time = Time.monotonic - start_time
 
-    Clear.logger.debug(("[" + Clear::SQL::Logger.display_time(elapsed_time).colorize.bold.white.to_s + "] #{SQL::Logger.colorize_query(sql)}"))
+    Clear.logger.debug(("[" + Clear::SQL::Logger.display_time(elapsed_time.to_f).colorize.bold.white.to_s + "] #{SQL::Logger.colorize_query(sql)}"))
 
     return o
   rescue e