Fix issue #710

helper/schema/resource_data.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/google/go-cmp/cmp"
 	"github.com/hashicorp/go-cty/cty"
 	"github.com/hashicorp/go-cty/cty/gocty"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/terraform"
@@ -155,14 +156,7 @@ func (d *ResourceData) HasChangesExcept(keys ...string) bool {
 func (d *ResourceData) HasChange(key string) bool {
 	o, n := d.GetChange(key)
 
-	// If the type implements the Equal interface, then call that
-	// instead of just doing a reflect.DeepEqual. An example where this is
-	// needed is *Set
-	if eq, ok := o.(Equal); ok {
-		return !eq.Equal(n)
-	}
-
-	return !reflect.DeepEqual(o, n)
+	return !cmp.Equal(n, o)
 }
 
 // HasChangeExcept returns whether any keys outside the given key have been changed.

helper/schema/resource_data_test.go

@@ -2075,6 +2075,42 @@ func TestResourceDataHasChange(t *testing.T) {
 
 			Change: false,
 		},
+
+		{
+			Schema: map[string]*Schema{
+				"network_configuration": {
+					Type:     TypeList,
+					MaxItems: 1,
+					Elem: &Resource{
+						Schema: map[string]*Schema{
+							"security_groups": {
+								Type:     TypeSet,
+								Optional: true,
+								Elem:     &Schema{Type: TypeString},
+								Set:      HashString,
+							},
+						},
+					},
+				},
+			},
+
+			State: &terraform.InstanceState{
+				Attributes: map[string]string{
+					"network_configuration.#":                     "1",
+					"network_configuration.0.security_groups.#":   "2",
+					"network_configuration.0.security_groups.sg1": "sg1",
+					"network_configuration.0.security_groups.sg2": "sg2",
+				},
+			},
+
+			Diff: &terraform.InstanceDiff{
+				Attributes: map[string]*terraform.ResourceAttrDiff{},
+			},
+
+			Key: "network_configuration",
+
+			Change: false,
+		},
 	}
 
 	for i, tc := range cases {

helper/schema/set.go

@@ -3,6 +3,7 @@ package schema
 import (
 	"bytes"
 	"fmt"
+	"github.com/google/go-cmp/cmp"
 	"reflect"
 	"sort"
 	"strconv"
@@ -150,46 +151,12 @@ func (s *Set) Union(other *Set) *Set {
 	return result
 }
 
-func checkSetMapEqual(m1, m2 map[string]interface{}) bool {
-	if (m1 == nil) != (m2 == nil) {
-		return false
-	}
-	if len(m1) != len(m2) {
-		return false
-	}
-	for k := range m1 {
-		v1 := m1[k]
-		v2, ok := m2[k]
-		if !ok {
-			return false
-		}
-		switch v1.(type) {
-		case map[string]interface{}:
-			same := checkSetMapEqual(v1.(map[string]interface{}), v2.(map[string]interface{}))
-			if !same {
-				return false
-			}
-		case *Set:
-			same := v1.(*Set).Equal(v2)
-			if !same {
-				return false
-			}
-		default:
-			same := reflect.DeepEqual(v1, v2)
-			if !same {
-				return false
-			}
-		}
-	}
-	return true
-}
-
 func (s *Set) Equal(raw interface{}) bool {
 	other, ok := raw.(*Set)
 	if !ok {
 		return false
 	}
-	return checkSetMapEqual(s.m, other.m)
+	return cmp.Equal(s.m, other.m)
 }
 
 // HashEqual simply checks to the keys the top-level map to the keys in the