added check command

examples/go/main.go

@@ -7,9 +7,7 @@ import (
 
 func main() {
 	pulumi.Run(func(ctx *pulumi.Context) error {
-		myModel, err := compose.NewInstanceResourceModel(ctx, "myModel", &compose.InstanceResourceModelArgs{
-			Length: pulumi.Int(24),
-		})
+		myModel, err := compose.NewInstanceResourceModel(ctx, "myModel", &compose.InstanceResourceModelArgs{})
 		if err != nil {
 			return err
 		}

provider/provider.go

@@ -15,6 +15,7 @@
 package provider
 
 import (
+	"github.com/pulumi/pulumi/sdk/v3/go/common/resource"
 	"math/rand"
 	"time"
 
@@ -58,7 +59,7 @@ type InstanceResourceModelArgs struct {
 	// Fields projected into Pulumi must be public and hava a `pulumi:"..."` tag.
 	// The pulumi tag doesn't need to match the field name, but it's generally a
 	// good idea.
-	Length int `pulumi:"length"`
+	Length int `pulumi:"length,optional"`
 }
 
 // Each resource has a state, describing the fields that exist on the created resource.
@@ -89,3 +90,10 @@ func determineResult(length int) string {
 	}
 	return string(result)
 }
+
+func (InstanceResourceModel) Check(ctx p.Context, name string, oldInputs, newInputs resource.PropertyMap) (InstanceResourceModelArgs, []p.CheckFailure, error) {
+	if _, ok := newInputs["length"]; !ok {
+		newInputs["length"] = resource.NewNumberProperty(12)
+	}
+	return infer.DefaultCheck[InstanceResourceModelArgs](newInputs)
+}

sdk/nodejs/compose/instanceResourceModel.ts

@@ -31,7 +31,7 @@ export class InstanceResourceModel extends pulumi.CustomResource {
         return obj['__pulumiType'] === InstanceResourceModel.__pulumiType;
     }
 
-    public readonly length!: pulumi.Output<number>;
+    public readonly length!: pulumi.Output<number | undefined>;
     public /*out*/ readonly result!: pulumi.Output<string>;
 
     /**
@@ -41,13 +41,10 @@ export class InstanceResourceModel extends pulumi.CustomResource {
      * @param args The arguments to use to populate this resource's properties.
      * @param opts A bag of options that control this resource's behavior.
      */
-    constructor(name: string, args: InstanceResourceModelArgs, opts?: pulumi.CustomResourceOptions) {
+    constructor(name: string, args?: InstanceResourceModelArgs, opts?: pulumi.CustomResourceOptions) {
         let resourceInputs: pulumi.Inputs = {};
         opts = opts || {};
         if (!opts.id) {
-            if ((!args || args.length === undefined) && !opts.urn) {
-                throw new Error("Missing required property 'length'");
-            }
             resourceInputs["length"] = args ? args.length : undefined;
             resourceInputs["result"] = undefined /*out*/;
         } else {
@@ -63,5 +60,5 @@ export class InstanceResourceModel extends pulumi.CustomResource {
  * The set of arguments for constructing a InstanceResourceModel resource.
  */
 export interface InstanceResourceModelArgs {
-    length: pulumi.Input<number>;
+    length?: pulumi.Input<number>;
 }

tests/provider_test.go

@@ -31,12 +31,16 @@ import (
 func TestInstanceResourceModelCreate(t *testing.T) {
 	prov := provider()
 
+	checkResponse, err := prov.Check(p.CheckRequest{
+		Urn:  urn("InstanceResourceModel"),
+		News: resource.PropertyMap{},
+	})
+	require.NoError(t, err)
+
 	response, err := prov.Create(p.CreateRequest{
-		Urn: urn("InstanceResourceModel"),
-		Properties: resource.PropertyMap{
-			"length": resource.NewNumberProperty(12),
-		},
-		Preview: false,
+		Urn:        urn("InstanceResourceModel"),
+		Properties: checkResponse.Inputs,
+		Preview:    false,
 	})
 
 	require.NoError(t, err)