allow specs to use multiple drivers

spec/custom_drivers_types_spec.cr

@@ -0,0 +1,134 @@
+require "./spec_helper"
+
+class GenericResultSet(T) < DB::ResultSet
+  def initialize(statement, @row : Array(T))
+    super(statement)
+    @index = 0
+  end
+
+  def move_next
+    @index = 0
+    true
+  end
+
+  def column_count : Int32
+    @row.size
+  end
+
+  def column_name(index : Int32) : String
+    index.to_s
+  end
+
+  def column_type(index : Int32)
+    @row[index].class
+  end
+
+  {% for t in DB::TYPES %}
+    # Reads the next column as a nillable {{t}}.
+    def read?(t : {{t}}.class) : {{t}}?
+      @index += 1
+      @row[@index - 1] as {{t}}?
+    end
+  {% end %}
+end
+
+class FooDriver < DB::Driver
+  @@row = [] of DB::Any
+
+  def self.fake_row=(row : Array(DB::Any))
+    @@row = row
+  end
+
+  def self.fake_row
+    @@row
+  end
+
+  def build_connection(db : DB::Database) : DB::Connection
+    FooConnection.new(db)
+  end
+
+  class FooConnection < DB::Connection
+    def build_statement(query)
+      FooStatement.new(self)
+    end
+  end
+
+  class FooStatement < DB::Statement
+    protected def perform_query(args : Slice(DB::Any)) : DB::ResultSet
+      GenericResultSet(DB::Any).new(self, FooDriver.fake_row)
+    end
+
+    protected def perform_exec(args : Slice(DB::Any)) : DB::ExecResult
+      raise "Not implemented"
+    end
+  end
+end
+
+DB.register_driver "foo", FooDriver
+
+class BarDriver < DB::Driver
+  @@row = [] of DB::Any
+
+  def self.fake_row=(row : Array(DB::Any))
+    @@row = row
+  end
+
+  def self.fake_row
+    @@row
+  end
+
+  def build_connection(db : DB::Database) : DB::Connection
+    BarConnection.new(db)
+  end
+
+  class BarConnection < DB::Connection
+    def build_statement(query)
+      BarStatement.new(self)
+    end
+  end
+
+  class BarStatement < DB::Statement
+    protected def perform_query(args : Slice(DB::Any)) : DB::ResultSet
+      GenericResultSet(DB::Any).new(self, BarDriver.fake_row)
+    end
+
+    protected def perform_exec(args : Slice(DB::Any)) : DB::ExecResult
+      raise "Not implemented"
+    end
+  end
+end
+
+DB.register_driver "bar", BarDriver
+
+describe DB do
+  it "should be able to register multiple drivers" do
+    DB.open("foo://host").driver.should be_a(FooDriver)
+    DB.open("bar://host").driver.should be_a(BarDriver)
+  end
+
+  it "Foo and Bar drivers should return fake_row" do
+    with_witness do |w|
+      DB.open("foo://host") do |db|
+        FooDriver.fake_row = [1, "string"] of DB::Any
+        db.query "query" do |rs|
+          w.check
+          rs.move_next
+          rs.read?(Int32).should eq(1)
+          rs.read?(String).should eq("string")
+        end
+      end
+    end
+
+    with_witness do |w|
+      DB.open("bar://host") do |db|
+        BarDriver.fake_row = ["lorem", 1.0] of DB::Any
+        db.query "query" do |rs|
+          w.check
+          rs.move_next
+          rs.read?(String).should eq("lorem")
+          rs.read?(Float64).should eq(1.0)
+        end
+      end
+    end
+  end
+end

spec/statement_spec.cr

@@ -9,7 +9,7 @@ describe DB::Statement do
 
   it "should initialize positional params in query" do
     with_dummy do |db|
-      stmt = db.prepare("the query")
+      stmt = db.prepare("the query").as(DummyDriver::DummyStatement)
       stmt.query "a", 1, nil
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -19,7 +19,7 @@ describe DB::Statement do
 
   it "should initialize positional params in query with array" do
     with_dummy do |db|
-      stmt = db.prepare("the query")
+      stmt = db.prepare("the query").as(DummyDriver::DummyStatement)
       stmt.query ["a", 1, nil]
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -29,7 +29,7 @@ describe DB::Statement do
 
   it "should initialize positional params in exec" do
     with_dummy do |db|
-      stmt = db.prepare("the query")
+      stmt = db.prepare("the query").as(DummyDriver::DummyStatement)
       stmt.exec "a", 1, nil
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -39,7 +39,7 @@ describe DB::Statement do
 
   it "should initialize positional params in exec with array" do
     with_dummy do |db|
-      stmt = db.prepare("the query")
+      stmt = db.prepare("the query").as(DummyDriver::DummyStatement)
       stmt.exec ["a", 1, nil]
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -49,7 +49,7 @@ describe DB::Statement do
 
   it "should initialize positional params in scalar" do
     with_dummy do |db|
-      stmt = db.prepare("the query")
+      stmt = db.prepare("the query").as(DummyDriver::DummyStatement)
       stmt.scalar "a", 1, nil
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)