terraform test: enable deferrals in Terraform Test with the specified flag (#37370)

Author: liamcervante

internal/backend/local/test.go

@@ -58,7 +58,8 @@ type TestSuiteRunner struct {
 	// Verbose tells the runner to print out plan files during each test run.
 	Verbose bool
 
-	Concurrency int
+	Concurrency     int
+	DeferralAllowed bool
 }
 
 func (runner *TestSuiteRunner) Stop() {
@@ -121,6 +122,7 @@ func (runner *TestSuiteRunner) Test() (moduletest.Status, tfdiags.Diagnostics) {
 			Render:            runner.View,
 			UnparsedVariables: currentGlobalVariables,
 			Concurrency:       runner.Concurrency,
+			DeferralAllowed:   runner.DeferralAllowed,
 		})
 
 		fileRunner := &TestFileRunner{

internal/command/arguments/test.go

@@ -47,6 +47,10 @@ type Test struct {
 	// human-readable format or JSON for each run step depending on the
 	// ViewType.
 	Verbose bool
+
+	// DeferralAllowed enables deferrals during test operations. This matches
+	// the same-named flag in the Operation struct.
+	DeferralAllowed bool
 }
 
 func ParseTest(args []string) (*Test, tfdiags.Diagnostics) {
@@ -65,6 +69,7 @@ func ParseTest(args []string) (*Test, tfdiags.Diagnostics) {
 	cmdFlags.BoolVar(&test.Verbose, "verbose", false, "verbose")
 	cmdFlags.IntVar(&test.OperationParallelism, "parallelism", DefaultParallelism, "parallelism")
 	cmdFlags.IntVar(&test.RunParallelism, "run-parallelism", DefaultParallelism, "run-parallelism")
+	cmdFlags.BoolVar(&test.DeferralAllowed, "allow-deferral", false, "allow-deferral")
 
 	// TODO: Finalise the name of this flag.
 	cmdFlags.StringVar(&test.CloudRunSource, "cloud-run", "", "cloud-run")

internal/command/test.go

@@ -111,6 +111,17 @@ func (c *TestCommand) Run(rawArgs []string) int {
 
 	view := views.NewTest(args.ViewType, c.View)
 
+	// EXPERIMENTAL: maybe enable deferred actions
+	if !c.AllowExperimentalFeatures && args.DeferralAllowed {
+		diags = diags.Append(tfdiags.Sourceless(
+			tfdiags.Error,
+			"Failed to parse command-line flags",
+			"The -allow-deferral flag is only valid in experimental builds of Terraform.",
+		))
+		view.Diagnostics(nil, nil, diags)
+		return 1
+	}
+
 	// The specified testing directory must be a relative path, and it must
 	// point to a directory that is a descendant of the configuration directory.
 	if !filepath.IsLocal(args.TestDirectory) {
@@ -228,6 +239,7 @@ func (c *TestCommand) Run(rawArgs []string) int {
 			Filter:              args.Filter,
 			Verbose:             args.Verbose,
 			Concurrency:         args.RunParallelism,
+			DeferralAllowed:     args.DeferralAllowed,
 		}
 
 		// JUnit output is only compatible with local test execution

internal/command/test_test.go

@@ -397,6 +397,11 @@ func TestTest_Runs(t *testing.T) {
 			expectedOut: []string{"1 passed, 0 failed."},
 			code:        0,
 		},
+		"deferred_changes": {
+			args:        []string{"-allow-deferral"},
+			expectedOut: []string{"3 passed, 0 failed."},
+			code:        0,
+		},
 	}
 	for name, tc := range tcs {
 		t.Run(name, func(t *testing.T) {
@@ -442,10 +447,11 @@ func TestTest_Runs(t *testing.T) {
 						},
 					},
 				},
-				Ui:             ui,
-				View:           view,
-				Streams:        streams,
-				ProviderSource: providerSource,
+				Ui:                        ui,
+				View:                      view,
+				Streams:                   streams,
+				ProviderSource:            providerSource,
+				AllowExperimentalFeatures: true,
 			}
 
 			init := &InitCommand{

internal/command/testdata/test/deferred_changes/create.tftest.hcl

@@ -0,0 +1,11 @@
+
+run "create" {
+  variables {
+    defer = true
+  }
+
+  assert {
+    condition = test_resource.resource.defer
+    error_message = "deferred resource attribute should be true"
+  }
+}

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

@@ -0,0 +1,7 @@
+variable "defer" {
+  type = bool
+}
+
+resource "test_resource" "resource" {
+  defer = var.defer
+}

internal/command/testdata/test/deferred_changes/update.tftest.hcl

@@ -0,0 +1,22 @@
+
+run "create" {
+  variables {
+    defer = false
+  }
+
+  assert {
+    condition = !test_resource.resource.defer
+    error_message = "deferred resource attribute should be false"
+  }
+}
+
+run "update" {
+  variables {
+    defer = true
+  }
+
+  assert {
+    condition = test_resource.resource.defer
+    error_message = "deferred resource attribute should be true"
+  }
+}

internal/command/testing/test_provider.go

@@ -40,6 +40,7 @@ var (
 						"create_wait_seconds":  {Type: cty.Number, Optional: true},
 						"destroy_wait_seconds": {Type: cty.Number, Optional: true},
 						"write_only":           {Type: cty.String, Optional: true, WriteOnly: true},
+						"defer":                {Type: cty.Bool, Optional: true},
 					},
 				},
 			},
@@ -61,6 +62,7 @@ var (
 						"destroy_fail":         {Type: cty.Bool, Computed: true},
 						"create_wait_seconds":  {Type: cty.Number, Computed: true},
 						"destroy_wait_seconds": {Type: cty.Number, Computed: true},
+						"defer":                {Type: cty.Bool, Computed: true},
 					},
 				},
 			},
@@ -227,9 +229,18 @@ func (provider *TestProvider) ConfigureProvider(request providers.ConfigureProvi
 
 func (provider *TestProvider) PlanResourceChange(request providers.PlanResourceChangeRequest) providers.PlanResourceChangeResponse {
 	if request.ProposedNewState.IsNull() {
+
+		var deferred *providers.Deferred
+		if shouldBeDeferred := request.PriorState.GetAttr("defer"); !shouldBeDeferred.IsNull() && shouldBeDeferred.True() {
+			deferred = &providers.Deferred{
+				Reason: providers.DeferredReasonResourceConfigUnknown,
+			}
+		}
+
 		// Then this is a delete operation.
 		return providers.PlanResourceChangeResponse{
 			PlannedState: request.ProposedNewState,
+			Deferred:     deferred,
 		}
 	}
 
@@ -252,8 +263,16 @@ func (provider *TestProvider) PlanResourceChange(request providers.PlanResourceC
 		resource = cty.ObjectVal(vals)
 	}
 
+	var deferred *providers.Deferred
+	if shouldBeDeferred := resource.GetAttr("defer"); !shouldBeDeferred.IsKnown() || (!shouldBeDeferred.IsNull() && shouldBeDeferred.True()) {
+		deferred = &providers.Deferred{
+			Reason: providers.DeferredReasonResourceConfigUnknown,
+		}
+	}
+
 	return providers.PlanResourceChangeResponse{
 		PlannedState: resource,
+		Deferred:     deferred,
 	}
 }
 

internal/moduletest/graph/eval_context.go

@@ -80,7 +80,8 @@ type EvalContext struct {
 	renderer views.Test
 	verbose  bool
 
-	evalSem terraform.Semaphore
+	deferralAllowed bool
+	evalSem         terraform.Semaphore
 }
 
 type EvalContextOpts struct {
@@ -91,6 +92,7 @@ type EvalContextOpts struct {
 	UnparsedVariables map[string]backendrun.UnparsedVariableValue
 	Config            *configs.Config
 	Concurrency       int
+	DeferralAllowed   bool
 }
 
 // NewEvalContext constructs a new graph evaluation context for use in
@@ -119,6 +121,7 @@ func NewEvalContext(opts EvalContextOpts) *EvalContext {
 		verbose:           opts.Verbose,
 		renderer:          opts.Render,
 		config:            opts.Config,
+		deferralAllowed:   opts.DeferralAllowed,
 		evalSem:           terraform.NewSemaphore(opts.Concurrency),
 	}
 }

internal/moduletest/graph/node_provider.go

@@ -90,7 +90,7 @@ func (n *NodeProviderConfigure) Execute(ctx *EvalContext) {
 		TerraformVersion: version.SemVer.String(),
 		Config:           unmarkedBody,
 		ClientCapabilities: providers.ClientCapabilities{
-			DeferralAllowed:            false, // TODO: Enable deferrals in test framework.
+			DeferralAllowed:            ctx.deferralAllowed,
 			WriteOnlyAttributesAllowed: true,
 		},
 	})