diff --git a/.rspec b/.rspec
new file mode 100644
index 0000000..5f16476
--- /dev/null
+++ b/.rspec
@@ -0,0 +1,2 @@
+--color
+--format progress
diff --git a/Rakefile b/Rakefile
old mode 100644
new mode 100755
index 58170c7..2995527
--- a/Rakefile
+++ b/Rakefile
@@ -1,9 +1 @@
-#!/usr/bin/env rake
 require "bundler/gem_tasks"
-require 'rake/testtask'
-
-Rake::TestTask.new do |t|
-  t.libs.push "lib"
-  t.test_files = FileList['spec/**/*_spec.rb']
-  t.verbose = true
-end
\ No newline at end of file
diff --git a/spec/biju/modem_spec.rb b/spec/biju/modem_spec.rb
deleted file mode 100644
index 6da75ce..0000000
--- a/spec/biju/modem_spec.rb
+++ /dev/null
@@ -1,10 +0,0 @@
-require_relative '../spec_helper'
-
-# TODO: Fix missing tests SOON
-describe Biju::Modem do
-  describe ".new" do
-    it "should raise an Exception without port option" do
-      lambda { Biju::Modem.new }.must_raise Exception
-    end
-  end
-end
\ No newline at end of file
diff --git a/spec/biju/parser_spec.rb b/spec/biju/parser_spec.rb
new file mode 100644
index 0000000..87c2422
--- /dev/null
+++ b/spec/biju/parser_spec.rb
@@ -0,0 +1,53 @@
+require 'spec_helper'
+require 'biju/parser'
+
+describe Biju::ATParser do
+  context "status" do
+    it "returns ok status" do
+      result = Biju::ATTransform.new.apply(Biju::ATParser.new.parse("OK\r"))
+      expect(result).to include(status: true)
+    end
+
+    it "returns error status" do
+      result = Biju::ATTransform.new.apply(Biju::ATParser.new.parse("ERROR\r"))
+      expect(result).to include(status: false)
+    end
+  end
+
+  context "response" do
+    it "parses messages list" do
+      messages = '+CMGL: 1,"REC READ","+85291234567",,"07/02/18,01:12:12+32"' <<
+                  "\r" <<
+                  "Reading text messages is easy.\r" <<
+                  '+CMGL: 2,"REC READ","+85291234567",,"07/02/18,00:07:22+32"' <<
+                  "\r" <<
+                  "A simple demo of SMS text messaging.\r" <<
+                  '+CMGL: 3,"REC READ","+85291234567",,"07/02/18,00:12:05+32"' <<
+                  "\r" <<
+                  "Hello, welcome to our SMS tutorial.\r" <<
+                  "\r" <<
+                  "OK\r"
+      result = Biju::ATTransform.new.apply(
+        Biju::ATParser.new.parse(messages))
+
+      expect(result).to include(status: true)
+      expect(result[:sms]).to have(3).messages
+      expect(result[:sms][0][:message]).to eq('Reading text messages is easy.')
+    end
+
+    it "gets messages storage" do
+      pms = "+CPMS: ((\"SM\",\"BM\",\"SR\"),(\"SM\"))\r"
+
+      result = Biju::ATTransform.new.apply(
+        Biju::ATParser.new.parse(pms))
+
+      expect(result[:cmd]).to eq('+CPMS')
+      expect(result[:array]).to have(2).storage
+      expect(result[:array][0]).to have(3).storage
+    end
+  end
+
+  it "raises ParseFailed exception" do
+    expect { Biju::ATParser.new.parse('Ha') }.to raise_error(Parslet::ParseFailed)
+  end
+end
diff --git a/spec/biju/sms_spec.rb b/spec/biju/sms_spec.rb
index 0cca416..7a4c428 100644
--- a/spec/biju/sms_spec.rb
+++ b/spec/biju/sms_spec.rb
@@ -1,15 +1,17 @@
-require_relative '../spec_helper'
+require 'spec_helper'
+require 'biju/sms'
 
 describe Biju::Sms do
-  subject { Biju::Sms.new(:id => "1", :phone_number => "144", :datetime => "11/07/28,15:34:08-12", :message => "Some text here")}
+  subject do
+    Biju::Sms.new(
+      id: 1,
+      phone_number: "144",
+      datetime: "11/07/28,15:34:08-12",
+      message: "Some text here")
+  end
 
-  it { subject.id.must_equal "1" }
-
-  it { subject.phone_number.must_equal "144" }
-
-  it { subject.datetime.must_equal "2011-07-28 15:34:08" }
-
-  it { subject.message.must_equal "Some text here" }
-
-  it { subject.to_s.must_equal "1 - 144 - 2011-07-28 15:34:08 - Some text here"}
-end
\ No newline at end of file
+  its(:id) { should eq(1) }
+  its(:phone_number) { should eq("144") }
+  its(:datetime) { should eq(DateTime.new(2011, 7, 28, 15, 34, 8)) }
+  its(:message) { should eq("Some text here") }
+end
diff --git a/spec/biju/to_hayes_spec.rb b/spec/biju/to_hayes_spec.rb
new file mode 100644
index 0000000..f03d7f1
--- /dev/null
+++ b/spec/biju/to_hayes_spec.rb
@@ -0,0 +1,10 @@
+require 'spec_helper'
+require 'biju/to_hayes'
+
+describe "blah blah" do
+  it { expect(5.to_hayes).to eq('5') }
+  it { expect(true.to_hayes).to eq('1') }
+  it { expect(false.to_hayes).to eq('0') }
+  it { expect("test".to_hayes).to eq('"test"') }
+  it { expect([1, 2].to_hayes).to eq('1,2') }
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index d0649f8..dbc4f1a 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,2 +1,17 @@
-require 'minitest/autorun'
-require "./lib/biju"
\ No newline at end of file
+# This file was generated by the `rspec --init` command. Conventionally, all
+# specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.
+# Require this file using `require "spec_helper"` to ensure that it is only
+# loaded once.
+#
+# See http://rubydoc.info/gems/rspec-core/RSpec/Core/Configuration
+RSpec.configure do |config|
+  config.treat_symbols_as_metadata_keys_with_true_values = true
+  config.run_all_when_everything_filtered = true
+  config.filter_run :focus
+
+  # Run specs in random order to surface order dependencies. If you find an
+  # order dependency and want to debug it, you can fix the order by providing
+  # the seed, which is printed after each run.
+  #     --seed 1234
+  config.order = 'random'
+end