Use ImportStatePersist to preserve state generated by import operation

.changelog/1052.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+helper/resource: Add ImportStatePersist to optionally persist state generated during import
+```

helper/resource/testing.go

@@ -564,6 +564,12 @@ type TestStep struct {
 	ImportStateVerify       bool
 	ImportStateVerifyIgnore []string
 
+	// ImportStatePersist, if true, will update the persisted state with the
+	// state generated by the import operation (i.e., terraform import). When
+	// false (default) the state generated by the import operation is discarded
+	// at the end of the test step that is verifying import behavior.
+	ImportStatePersist bool
+
 	// ProviderFactories can be specified for the providers that are valid for
 	// this TestStep. When providers are specified at the TestStep level, all
 	// TestStep within a TestCase must declare providers.

helper/resource/testing_new_import_state.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 
 	"github.com/davecgh/go-spew/spew"
-	testing "github.com/mitchellh/go-testing-interface"
+	"github.com/mitchellh/go-testing-interface"
 
 	"github.com/hashicorp/terraform-plugin-sdk/v2/internal/logging"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/internal/plugintest"
@@ -86,20 +86,31 @@ func testStepNewImportState(ctx context.Context, t testing.T, helper *plugintest
 			t.Fatal("Cannot import state with no specified config")
 		}
 	}
-	importWd := helper.RequireNewWorkingDir(ctx, t)
-	defer importWd.Close()
+
+	var importWd *plugintest.WorkingDir
+
+	// Use the same working directory to persist the state from import
+	if step.ImportStatePersist {
+		importWd = wd
+	} else {
+		importWd = helper.RequireNewWorkingDir(ctx, t)
+		defer importWd.Close()
+	}
+
 	err = importWd.SetConfig(ctx, step.Config)
 	if err != nil {
 		t.Fatalf("Error setting test config: %s", err)
 	}
 
 	logging.HelperResourceDebug(ctx, "Running Terraform CLI init and import")
 
-	err = runProviderCommand(ctx, t, func() error {
-		return importWd.Init(ctx)
-	}, importWd, providers)
-	if err != nil {
-		t.Fatalf("Error running init: %s", err)
+	if !step.ImportStatePersist {
+		err = runProviderCommand(ctx, t, func() error {
+			return importWd.Init(ctx)
+		}, importWd, providers)
+		if err != nil {
+			t.Fatalf("Error running init: %s", err)
+		}
 	}
 
 	err = runProviderCommand(ctx, t, func() error {