feat: add state_alias for test run blocks

internal/backend/local/test.go

@@ -346,12 +346,16 @@ func (runner *TestFileRunner) Test(file *moduletest.File) {
 				file.Status = moduletest.Error
 				continue // Abort!
 			}
+		}
 
-			if _, exists := runner.RelevantStates[key]; !exists {
-				runner.RelevantStates[key] = &TestFileState{
-					Run:   nil,
-					State: states.NewState(),
-				}
+		if run.Config.Options.StateAlias != "" {
+			key = run.Config.Options.StateAlias
+		}
+
+		if _, exists := runner.RelevantStates[key]; !exists {
+			runner.RelevantStates[key] = &TestFileState{
+				Run:   nil,
+				State: states.NewState(),
 			}
 		}
 

internal/command/test_test.go

@@ -275,6 +275,11 @@ func TestTest_Runs(t *testing.T) {
 			expectedErr: []string{"Ephemeral resource instance has expired", "Ephemeral resources cannot be asserted"},
 			code:        1,
 		},
+		"with_state_alias": {
+			expectedOut: []string{"3 passed, 1 failed."},
+			expectedErr: []string{"Test assertion failed", "resource renamed without moved block"},
+			code:        1,
+		},
 	}
 	for name, tc := range tcs {
 		t.Run(name, func(t *testing.T) {

internal/command/testdata/test/with_state_alias/breaking_change.tftest.hcl

@@ -0,0 +1,18 @@
+run "old_version" {
+  plan_options {
+    state_alias = "test1"
+  }
+}
+
+run "new_code" {
+  module {
+    source = "./breaking_change"
+  }
+  plan_options {
+    state_alias = "test1"
+  }
+  assert {
+    condition = test_resource.renamed_without_move.id == run.old_version.test_id
+    error_message = "resource renamed without moved block"
+  }
+}

internal/command/testdata/test/with_state_alias/breaking_change/main.tf

@@ -0,0 +1,7 @@
+resource "test_resource" "renamed_without_move" {
+  value = "test"
+}
+
+output "test_id" {
+  value = test_resource.renamed_without_move.id
+}

internal/command/testdata/test/with_state_alias/main.tf

@@ -0,0 +1,11 @@
+resource "test_resource" "test_id_moved" {
+}
+
+output "test_id" {
+  value = test_resource.test_id_moved.id
+}
+
+moved {
+  from = test_resource.test_id
+  to   = test_resource.test_id_moved
+}

internal/command/testdata/test/with_state_alias/moved.tftest.hcl

@@ -0,0 +1,18 @@
+run "old_version" {
+  module {
+    source = "./old_version"
+  }
+  plan_options {
+    state_alias = "test1"
+  }
+}
+
+run "new_code" {
+  plan_options {
+    state_alias = "test1"
+  }
+  assert {
+    condition = test_resource.test_id_moved.id == run.old_version.test_id
+    error_message = "ressource_id differed"
+  }
+}

internal/command/testdata/test/with_state_alias/old_version/main.tf

@@ -0,0 +1,7 @@
+resource "test_resource" "test_id" {
+  value = "test"
+}
+
+output "test_id" {
+  value = test_resource.test_id.id
+}

internal/configs/test_file.go

@@ -275,6 +275,8 @@ type TestRunOptions struct {
 	// Refresh is analogous to the -refresh=false Terraform plan option.
 	Refresh bool
 
+	StateAlias string
+
 	// Replace is analogous to the -replace=ADDRESS Terraform plan option.
 	Replace []hcl.Traversal
 
@@ -760,6 +762,11 @@ func decodeTestRunOptionsBlock(block *hcl.Block) (*TestRunOptions, hcl.Diagnosti
 		opts.Target = tars
 	}
 
+	if attr, exists := content.Attributes["state_alias"]; exists {
+		rawDiags := gohcl.DecodeExpression(attr.Expr, nil, &opts.StateAlias)
+		diags = append(diags, rawDiags...)
+	}
+
 	if !opts.Refresh && opts.Mode == RefreshOnlyTestMode {
 		// These options are incompatible.
 		diags = append(diags, &hcl.Diagnostic{
@@ -839,6 +846,7 @@ var testRunOptionsBlockSchema = &hcl.BodySchema{
 		{Name: "refresh"},
 		{Name: "replace"},
 		{Name: "target"},
+		{Name: "state_alias"},
 	},
 }