suppress diff on website

.changelog/6827.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+storage: fixed permdiff when `website`, `website.main_page_suffix`, `website.not_found_page` are removed on `google_storage_bucket`
+```

google/resource_storage_bucket.go

@@ -251,19 +251,26 @@ func resourceStorageBucket() *schema.Resource {
 				Type:     schema.TypeList,
 				Optional: true,
 				MaxItems: 1,
+				Computed: true,
 				Elem: &schema.Resource{
 					Schema: map[string]*schema.Schema{
 						"main_page_suffix": {
 							Type:         schema.TypeString,
 							Optional:     true,
 							AtLeastOneOf: []string{"website.0.not_found_page", "website.0.main_page_suffix"},
 							Description:  `Behaves as the bucket's directory index where missing objects are treated as potential directories.`,
+							DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool {
+								return old != "" && new == ""
+							},
 						},
 						"not_found_page": {
 							Type:         schema.TypeString,
 							Optional:     true,
 							AtLeastOneOf: []string{"website.0.main_page_suffix", "website.0.not_found_page"},
 							Description:  `The custom object to return when a requested resource is not found.`,
+							DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool {
+								return old != "" && new == ""
+							},
 						},
 					},
 				},

google/resource_storage_bucket_test.go

@@ -1016,6 +1016,15 @@ func TestAccStorageBucket_website(t *testing.T) {
 				ImportStateVerify:       true,
 				ImportStateVerifyIgnore: []string{"force_destroy"},
 			},
+			{
+				Config: testAccStorageBucket_websiteOneAttributeUpdate(bucketSuffix),
+			},
+			{
+				ResourceName:            "google_storage_bucket.website",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"force_destroy"},
+			},
 			{
 				Config: testAccStorageBucket_website(bucketSuffix),
 			},
@@ -1025,6 +1034,15 @@ func TestAccStorageBucket_website(t *testing.T) {
 				ImportStateVerify:       true,
 				ImportStateVerifyIgnore: []string{"force_destroy"},
 			},
+			{
+				Config: testAccStorageBucket_websiteRemoved(bucketSuffix),
+			},
+			{
+				ResourceName:            "google_storage_bucket.website",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"force_destroy"},
+			},
 		},
 	})
 }
@@ -1939,6 +1957,17 @@ resource "google_storage_bucket" "website" {
 `, bucketName)
 }
 
+func testAccStorageBucket_websiteRemoved(bucketName string) string {
+	return fmt.Sprintf(`
+resource "google_storage_bucket" "website" {
+  name          = "%s.gcp.tfacc.hashicorptest.com"
+  location      = "US"
+  storage_class = "STANDARD"
+  force_destroy = true
+}
+`, bucketName)
+}
+
 func testAccStorageBucket_websiteOneAttribute(bucketName string) string {
 	return fmt.Sprintf(`
 resource "google_storage_bucket" "website" {
@@ -1954,6 +1983,21 @@ resource "google_storage_bucket" "website" {
 `, bucketName)
 }
 
+func testAccStorageBucket_websiteOneAttributeUpdate(bucketName string) string {
+	return fmt.Sprintf(`
+resource "google_storage_bucket" "website" {
+  name          = "%s.gcp.tfacc.hashicorptest.com"
+  location      = "US"
+  storage_class = "STANDARD"
+  force_destroy = true
+
+  website {
+    main_page_suffix = "default.html"
+  }
+}
+`, bucketName)
+}
+
 func testAccStorageBucket_forceDestroy(bucketName string) string {
 	return fmt.Sprintf(`
 resource "google_storage_bucket" "bucket" {