Upgrade the test to be based on go module and add Terraform plan test

.gitignore

@@ -4,6 +4,7 @@ terraform.tfvars
 # Compiled files
 *.tfstate
 *.tfstate.backup
+.terraform.lock.hcl
 .DS_Store
 terraform.log
 
@@ -34,3 +35,4 @@ tags
 
 # Ruby download package lock file.
 Gemfile.lock
+go.sum

Dockerfile

@@ -34,4 +34,6 @@ ENV PATH /usr/local/go/bin:$GOPATH/bin:$PATH
 RUN go get github.com/katbyte/terrafmt
 RUN /bin/bash -c "curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh"
 
+RUN ["bundle", "update", "--bundler"]
 RUN ["bundle", "install", "--gemfile", "./Gemfile"]
+RUN curl -sL https://aka.ms/InstallAzureCLIDeb | bash

Rakefile

@@ -7,13 +7,26 @@ require 'bundler/setup'
 require 'terramodtest'
 
 namespace :presteps do
+  task :fmt do
+    puts "Format Terraform code.\n"
+    success = system('terraform fmt --recursive .')
+    if not success 
+      raise "ERROR: Terraform format failed.\n".red
+    end
+  end
+
   task :ensure do
-    puts "Using dep ensure to install required go packages.\n"
-    success = system ("dep ensure")
+    puts "Downloading missing go modules and remove unused ones.\n"
+    success = system('go get github.com/katbyte/terrafmt && go mod tidy')
     if not success 
-      raise "ERROR: Dep ensure failed!\n".red
+      raise "ERROR: Failed to tidy go depedencies!\n".red
     end
   end
+
+  task :clean do
+    puts "Clean out the temporary terraform files in test folder.\n"
+    FileUtils.rm_r(['./test/fixture/.terraform', './test/fixture/.terraform.lock.hcl'], force: true)
+  end
 end
 
 namespace :static do
@@ -34,26 +47,33 @@ namespace :static do
   end
 end
 
-namespace :integration do
-  task :test do
-    success = system ("go test -v ./test/ -timeout 20m")
+namespace :test do
+  task :unit do
+    success = system ("go test -v ./test/unit/ -timeout 20m")
+    if not success 
+      raise "ERROR: Go test failed!\n".red
+    end
+  end
+
+  task :integration do
+    success = system ("go test -v ./test/integration -timeout 20m")
     if not success 
       raise "ERROR: Go test failed!\n".red
     end
   end
 end
 
-task :prereqs => [ 'presteps:ensure' ]
+task :prereqs => [  'presteps:fmt', 'presteps:ensure', 'presteps:clean' ]
 
 task :validate => [ 'static:style', 'static:lint', 'static:readme_style','static:fixture_style' ]
 
 task :format => [ 'static:format' ]
 
 task :build => [ 'prereqs', 'validate' ]
 
-task :unit => []
+task :unit => [  'build', 'test:unit' ]
 
-task :e2e => [ 'integration:test' ]
+task :e2e => [  'build', 'test:integration' ]
 
 task :default => [ 'build' ]
 

go.mod

@@ -0,0 +1,17 @@
+module github.com/Azure/terraform-azurerm-vnet
+
+go 1.16
+
+require (
+	github.com/agext/levenshtein v1.2.3 // indirect
+	github.com/google/go-cmp v0.5.2 // indirect
+	github.com/gruntwork-io/terratest v0.36.3
+	github.com/imdario/mergo v0.3.9 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/kylelemons/godebug v1.1.0 // indirect
+	github.com/mitchellh/go-wordwrap v1.0.0 // indirect
+	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/zclconf/go-cty v1.5.1 // indirect
+	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
+	gopkg.in/yaml.v2 v2.3.0 // indirect
+)

test/integration/terrraform_vnet_test.go

@@ -0,0 +1,55 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/gruntwork-io/terratest/modules/terraform"
+	"github.com/gruntwork-io/terratest/modules/test-structure"
+)
+
+func TestTerraformVnet(t *testing.T) {
+	t.Parallel()
+
+	fixtureFolder := "../fixture"
+
+	// Deploy the example
+	test_structure.RunTestStage(t, "setup", func() {
+		terraformOptions := configureTerraformOptions(t, fixtureFolder)
+
+		// Save the options so later test stages can use them
+		test_structure.SaveTerraformOptions(t, fixtureFolder, terraformOptions)
+
+		// This will init and apply the resources and fail the test if there are any errors
+		terraform.InitAndApply(t, terraformOptions)
+	})
+
+	// Check whether the length of output meets the requirement
+	test_structure.RunTestStage(t, "validate", func() {
+		terraformOptions := test_structure.LoadTerraformOptions(t, fixtureFolder)
+
+		string := terraform.Output(t, terraformOptions, "test_vnet_id")
+		if len(string) <= 0 {
+			t.Fatal("Wrong output")
+		}
+	})
+
+	// At the end of the test, clean up any resources that were created
+	test_structure.RunTestStage(t, "teardown", func() {
+		terraformOptions := test_structure.LoadTerraformOptions(t, fixtureFolder)
+		terraform.Destroy(t, terraformOptions)
+	})
+
+}
+
+func configureTerraformOptions(t *testing.T, fixtureFolder string) *terraform.Options {
+
+	terraformOptions := &terraform.Options{
+		// The path to where our Terraform code is located
+		TerraformDir: fixtureFolder,
+
+		// Variables to pass to our Terraform code using -var options
+		Vars: map[string]interface{}{},
+	}
+
+	return terraformOptions
+}

test/unit/plan_test.go

@@ -0,0 +1,17 @@
+package unit
+
+import (
+	"testing"
+
+	"github.com/gruntwork-io/terratest/modules/terraform"
+)
+
+func TestPlan(t *testing.T) {
+	tfOptions := &terraform.Options{
+		TerraformDir: "../fixture",
+		Vars:         map[string]interface{}{},
+	}
+
+	terraform.Init(t, tfOptions)
+	terraform.Plan(t, tfOptions)
+}