tfprotov5+tfprotov6: Add action validation RPC + fix proto field numbering (#539)

* proto changes

* add validate rpc

Author: austinvalle

tfprotov5/action.go

@@ -16,6 +16,13 @@ type ActionMetadata struct {
 
 // ActionServer is an interface containing the methods an action implementation needs to fill.
 type ActionServer interface {
+	// ValidateActionConfig is called when Terraform is checking that an
+	// action configuration is valid. It is guaranteed to have types
+	// conforming to your schema, but it is not guaranteed that all values
+	// will be known. This is your opportunity to do custom or advanced
+	// validation prior to an action being planned/invoked.
+	ValidateActionConfig(context.Context, *ValidateActionConfigRequest) (*ValidateActionConfigResponse, error)
+
 	// PlanAction is called when Terraform is attempting to
 	// calculate a plan for an action. Depending on the type defined in
 	// the action schema, Terraform may also pass the plan of linked resources
@@ -32,6 +39,35 @@ type ActionServer interface {
 	InvokeAction(context.Context, *InvokeActionRequest) (*InvokeActionServerStream, error)
 }
 
+// ValidateActionConfigRequest is the request Terraform sends when it
+// wants to validate an action's configuration.
+type ValidateActionConfigRequest struct {
+	// ActionType is the type of action Terraform is validating.
+	ActionType string
+
+	// Config is the configuration the user supplied for that action. See
+	// the documentation on `DynamicValue` for more information about
+	// safely accessing the configuration.
+	//
+	// The configuration is represented as a tftypes.Object, with each
+	// attribute and nested block getting its own key and value.
+	//
+	// This configuration may contain unknown values if a user uses
+	// interpolation or other functionality that would prevent Terraform
+	// from knowing the value at request time. Any attributes not directly
+	// set in the configuration will be null.
+	Config *DynamicValue
+}
+
+// ValidateActionConfigResponse is the response from the provider about
+// the validity of an action's configuration.
+type ValidateActionConfigResponse struct {
+	// Diagnostics report errors or warnings related to the given
+	// configuration. Returning an empty slice indicates a successful
+	// validation with no warnings or errors generated.
+	Diagnostics []*Diagnostic
+}
+
 // PlanActionRequest is the request Terraform sends when it is attempting to
 // calculate a plan for an action.
 type PlanActionRequest struct {

tfprotov5/internal/fromproto/action.go

@@ -8,6 +8,17 @@ import (
 	"github.com/hashicorp/terraform-plugin-go/tfprotov5/internal/tfplugin5"
 )
 
+func ValidateActionConfigRequest(in *tfplugin5.ValidateActionConfig_Request) *tfprotov5.ValidateActionConfigRequest {
+	if in == nil {
+		return nil
+	}
+
+	return &tfprotov5.ValidateActionConfigRequest{
+		ActionType: in.ActionType,
+		Config:     DynamicValue(in.Config),
+	}
+}
+
 func PlanActionRequest(in *tfplugin5.PlanAction_Request) *tfprotov5.PlanActionRequest {
 	if in == nil {
 		return nil

tfprotov5/internal/fromproto/actions_test.go

@@ -12,6 +12,52 @@ import (
 	"github.com/hashicorp/terraform-plugin-go/tfprotov5/internal/tfplugin5"
 )
 
+func TestValidateActionConfigRequest(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		in       *tfplugin5.ValidateActionConfig_Request
+		expected *tfprotov5.ValidateActionConfigRequest
+	}{
+		"nil": {
+			in:       nil,
+			expected: nil,
+		},
+		"zero": {
+			in:       &tfplugin5.ValidateActionConfig_Request{},
+			expected: &tfprotov5.ValidateActionConfigRequest{},
+		},
+		"Config": {
+			in: &tfplugin5.ValidateActionConfig_Request{
+				Config: testTfplugin5DynamicValue(),
+			},
+			expected: &tfprotov5.ValidateActionConfigRequest{
+				Config: testTfprotov5DynamicValue(),
+			},
+		},
+		"ActionType": {
+			in: &tfplugin5.ValidateActionConfig_Request{
+				ActionType: "test",
+			},
+			expected: &tfprotov5.ValidateActionConfigRequest{
+				ActionType: "test",
+			},
+		},
+	}
+
+	for name, testCase := range testCases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			got := fromproto.ValidateActionConfigRequest(testCase.in)
+
+			if diff := cmp.Diff(got, testCase.expected); diff != "" {
+				t.Errorf("unexpected difference: %s", diff)
+			}
+		})
+	}
+}
+
 func TestPlanActionRequest(t *testing.T) {
 	t.Parallel()