Restructure project

We previously didn't really had any structure in our project apart
from creating a new folder for each package in our project root.
Now that we have accumulated some packages, we use the well-known
Golang project layout in order to clearly communicate our intent
with packages. See https://github.com/golang-standards/project-layout

internal/runner/nomad_environment_storage_test.go

@@ -0,0 +1,76 @@
+package runner
+
+import (
+	nomadApi "github.com/hashicorp/nomad/api"
+	"github.com/stretchr/testify/suite"
+	"testing"
+)
+
+func TestEnvironmentStoreTestSuite(t *testing.T) {
+	suite.Run(t, new(EnvironmentStoreTestSuite))
+}
+
+type EnvironmentStoreTestSuite struct {
+	suite.Suite
+	environmentStorage *localNomadEnvironmentStorage
+	environment        *NomadEnvironment
+}
+
+func (s *EnvironmentStoreTestSuite) SetupTest() {
+	s.environmentStorage = NewLocalNomadEnvironmentStorage()
+	s.environment = &NomadEnvironment{environmentID: defaultEnvironmentID}
+}
+
+func (s *EnvironmentStoreTestSuite) TestAddedEnvironmentCanBeRetrieved() {
+	s.environmentStorage.Add(s.environment)
+	retrievedEnvironment, ok := s.environmentStorage.Get(s.environment.ID())
+	s.True(ok, "A saved runner should be retrievable")
+	s.Equal(s.environment, retrievedEnvironment)
+}
+
+func (s *EnvironmentStoreTestSuite) TestEnvironmentWithSameIdOverwritesOldOne() {
+	otherEnvironmentWithSameID := &NomadEnvironment{environmentID: defaultEnvironmentID}
+	otherEnvironmentWithSameID.templateJob = &nomadApi.Job{}
+	s.NotEqual(s.environment, otherEnvironmentWithSameID)
+
+	s.environmentStorage.Add(s.environment)
+	s.environmentStorage.Add(otherEnvironmentWithSameID)
+	retrievedEnvironment, _ := s.environmentStorage.Get(s.environment.ID())
+	s.NotEqual(s.environment, retrievedEnvironment)
+	s.Equal(otherEnvironmentWithSameID, retrievedEnvironment)
+}
+
+func (s *EnvironmentStoreTestSuite) TestDeletedEnvironmentIsNotAccessible() {
+	s.environmentStorage.Add(s.environment)
+	s.environmentStorage.Delete(s.environment.ID())
+	retrievedRunner, ok := s.environmentStorage.Get(s.environment.ID())
+	s.Nil(retrievedRunner)
+	s.False(ok, "A deleted runner should not be accessible")
+}
+
+func (s *EnvironmentStoreTestSuite) TestLenOfEmptyPoolIsZero() {
+	s.Equal(0, s.environmentStorage.Length())
+}
+
+func (s *EnvironmentStoreTestSuite) TestLenChangesOnStoreContentChange() {
+	s.Run("len increases when environment is added", func() {
+		s.environmentStorage.Add(s.environment)
+		s.Equal(1, s.environmentStorage.Length())
+	})
+
+	s.Run("len does not increase when environment with same id is added", func() {
+		s.environmentStorage.Add(s.environment)
+		s.Equal(1, s.environmentStorage.Length())
+	})
+
+	s.Run("len increases again when different environment is added", func() {
+		anotherEnvironment := &NomadEnvironment{environmentID: anotherEnvironmentID}
+		s.environmentStorage.Add(anotherEnvironment)
+		s.Equal(2, s.environmentStorage.Length())
+	})
+
+	s.Run("len decreases when environment is deleted", func() {
+		s.environmentStorage.Delete(s.environment.ID())
+		s.Equal(1, s.environmentStorage.Length())
+	})
+}