Use ImportStatePersist to preserve state generated by import operation (#1052)

* Use ImportStatePersist to preserve state generated by import operation (#717)

* Removing additional call to Init as this has already been called in runNewTest and when called at this point will overwrite the contents of the .terraform directory with the current version of the provider  (#717)

* Adding CHANGELOG entry (#717)

* Adding test coverage (#717)

* Linting (#717)

* Appears that init needs to be run within testStepNewImportState if we're not persisting the state generated by the import (#717)

* Fixing test and adding a couple of additional tests to verify that import test works when ImportStatePersist is false (#717)

* Linting (#717)

Author: bendbennett

.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 {