fix to free/starter functions region in build settings

internal/provider/free_plan_test.go

@@ -0,0 +1,59 @@
+package provider
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
+	"github.com/hashicorp/terraform-plugin-testing/terraform"
+)
+
+func TestAccFreeEnvVar(t *testing.T) {
+	accTest(t, []resource.TestStep{
+		{
+			Config: `resource "netlify_environment_variable" "site_level" {
+  team_id = "66e98216e3fe031846dc998a"
+  site_id = "fbba82b0-f1e9-4e92-9203-eefc62857545"
+  key     = "TEST_SITE_LEVEL"
+  values = [
+    {
+      value   = "/path/here",
+      context = "all",
+    }
+  ]
+}
+`,
+			Check: resource.ComposeAggregateTestCheckFunc(
+				resource.TestCheckResourceAttr("netlify_environment_variable.site_level", "team_id", "66e98216e3fe031846dc998a"),
+				resource.TestCheckResourceAttr("netlify_environment_variable.site_level", "site_id", "fbba82b0-f1e9-4e92-9203-eefc62857545"),
+				resource.TestCheckResourceAttr("netlify_environment_variable.site_level", "key", "TEST_SITE_LEVEL"),
+			),
+		},
+	}, func(s *terraform.State) error { return nil })
+}
+
+func TestAccFreeSiteBuildSettings(t *testing.T) {
+	accTest(t, []resource.TestStep{
+		{
+			Config: `resource "netlify_site_build_settings" "example" {
+  site_id                = "3a3c2d0f-4e59-46c0-ae6a-4bdc0d49aca9"
+  build_command          = "npm run build"
+  publish_directory      = "dist"
+  production_branch      = "main"
+}`,
+			Check: resource.ComposeAggregateTestCheckFunc(
+				resource.TestCheckResourceAttr("netlify_site_build_settings.example", "site_id", "3a3c2d0f-4e59-46c0-ae6a-4bdc0d49aca9"),
+				resource.TestCheckResourceAttr("netlify_site_build_settings.example", "build_command", "npm run build"),
+				resource.TestCheckResourceAttr("netlify_site_build_settings.example", "publish_directory", "dist"),
+				resource.TestCheckResourceAttr("netlify_site_build_settings.example", "production_branch", "main"),
+			),
+		},
+		{
+			ResourceName:                         "netlify_site_build_settings.example",
+			ImportState:                          true,
+			ImportStateId:                        "3a3c2d0f-4e59-46c0-ae6a-4bdc0d49aca9",
+			ImportStateVerifyIdentifierAttribute: "site_id",
+			ImportStateVerify:                    true,
+			ImportStateVerifyIgnore:              []string{"last_updated"},
+		},
+	}, func(s *terraform.State) error { return nil })
+}

internal/provider/site_build_settings_resource.go

@@ -359,6 +359,11 @@ func (r *siteBuildSettingsResource) write(ctx context.Context, plan *siteBuildSe
 	} else {
 		site.FunctionsRegion = plan.FunctionsRegion.ValueStringPointer()
 	}
+	if site.FunctionsRegion != nil &&
+		curState.FunctionsRegion.ValueStringPointer() != nil &&
+		*site.FunctionsRegion == curState.FunctionsRegion.ValueString() {
+		site.FunctionsRegion = nil
+	}
 
 	_, _, err := r.data.client.SitesAPI.
 		UpdateSite(ctx, plan.SiteID.ValueString()).