Migrate to terraform-plugin-testing (#132)

Reference: https://discuss.hashicorp.com/t/announcing-the-terraform-plugin-testing-module/49914

This will ensure that developers cloning this template repository will get the most current Go module for provider testing.

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/hashicorp/terraform-plugin-framework v1.1.1
 	github.com/hashicorp/terraform-plugin-go v0.14.3
 	github.com/hashicorp/terraform-plugin-log v0.8.0
-	github.com/hashicorp/terraform-plugin-sdk/v2 v2.25.0
+	github.com/hashicorp/terraform-plugin-testing v1.1.0
 )
 
 require (
@@ -36,6 +36,7 @@ require (
 	github.com/hashicorp/logutils v1.0.0 // indirect
 	github.com/hashicorp/terraform-exec v0.18.1 // indirect
 	github.com/hashicorp/terraform-json v0.15.0 // indirect
+	github.com/hashicorp/terraform-plugin-sdk/v2 v2.25.0 // indirect
 	github.com/hashicorp/terraform-registry-address v0.1.0 // indirect
 	github.com/hashicorp/terraform-svchost v0.0.0-20200729002733-f050f53b9734 // indirect
 	github.com/hashicorp/yamux v0.0.0-20181012175058-2f1d1f20f75d // indirect

go.sum

@@ -124,6 +124,8 @@ github.com/hashicorp/terraform-plugin-log v0.8.0 h1:pX2VQ/TGKu+UU1rCay0OlzosNKe4
 github.com/hashicorp/terraform-plugin-log v0.8.0/go.mod h1:1myFrhVsBLeylQzYYEV17VVjtG8oYPRFdaZs7xdW2xs=
 github.com/hashicorp/terraform-plugin-sdk/v2 v2.25.0 h1:iNRjaJCatQS1rIbHs/vDvJ0GECsaGgxx780chA2Irpk=
 github.com/hashicorp/terraform-plugin-sdk/v2 v2.25.0/go.mod h1:XnVNLIS6bdMJbjSDujhX4Rlk24QpbGKbnrVFM4tZ7OU=
+github.com/hashicorp/terraform-plugin-testing v1.1.0 h1:l5UuTAt7yQcThGe0dFGSCOHR4M1k0VVTqW60K2+q6AE=
+github.com/hashicorp/terraform-plugin-testing v1.1.0/go.mod h1:D52zIrX/2hgLsUYMj3tfiLAOFJzhGf8GDv/8nCCtPKA=
 github.com/hashicorp/terraform-registry-address v0.1.0 h1:W6JkV9wbum+m516rCl5/NjKxCyTVaaUBbzYcMzBDO3U=
 github.com/hashicorp/terraform-registry-address v0.1.0/go.mod h1:EnyO2jYO6j29DTHbJcm00E5nQTFeTtyZH3H5ycydQ5A=
 github.com/hashicorp/terraform-svchost v0.0.0-20200729002733-f050f53b9734 h1:HKLsbzeOsfXmKNpr3GiT18XAblV0BjCbzL8KQAMZGa0=

internal/provider/example_data_source_test.go

@@ -3,7 +3,7 @@ package provider
 import (
 	"testing"
 
-	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
 )
 
 func TestAccExampleDataSource(t *testing.T) {

internal/provider/example_resource_test.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"testing"
 
-	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
 )
 
 func TestAccExampleResource(t *testing.T) {