feat: add support for the 'Version' resource attribute

As it turns out, there's one more resource attribute that we don't support currently:
Version, used for custom CloudFormation resources.

packages/@aws-cdk/cloudformation-include/lib/cfn-include.ts

@@ -550,12 +550,12 @@ export class CfnInclude extends core.CfnElement {
 
     // fail early for resource attributes we don't support yet
     const knownAttributes = [
-      'Type', 'Properties', 'Condition', 'DependsOn', 'Metadata',
+      'Type', 'Properties', 'Condition', 'DependsOn', 'Metadata', 'Version',
       'CreationPolicy', 'UpdatePolicy', 'DeletionPolicy', 'UpdateReplacePolicy',
     ];
     for (const attribute of Object.keys(resourceAttributes)) {
       if (!knownAttributes.includes(attribute)) {
-        throw new Error(`The ${attribute} resource attribute is not supported by cloudformation-include yet. ` +
+        throw new Error(`The '${attribute}' resource attribute is not supported by cloudformation-include yet. ` +
           'Either remove it from the template, or use the CdkInclude class from the core package instead.');
       }
     }

packages/@aws-cdk/cloudformation-include/test/invalid-templates.test.ts

@@ -80,7 +80,7 @@ describe('CDK Include', () => {
   test('throws a validation exception when encountering an unrecognized resource attribute', () => {
     expect(() => {
       includeTestTemplate(stack, 'non-existent-resource-attribute.json');
-    }).toThrow(/The NonExistentResourceAttribute resource attribute is not supported by cloudformation-include yet/);
+    }).toThrow(/The 'NonExistentResourceAttribute' resource attribute is not supported by cloudformation-include yet/);
   });
 
   test("throws a validation exception when encountering a Ref-erence to a template element that doesn't exist", () => {

packages/@aws-cdk/cloudformation-include/test/test-templates/custom-resource-with-attributes.json

@@ -13,6 +13,7 @@
     "CustomBucket": {
       "Type": "AWS::MyService::Custom",
       "Condition": "AlwaysFalseCond",
+      "Version": "1.0",
       "Metadata": {
         "Object1": "Value1",
         "Object2": "Value2"

packages/@aws-cdk/core/lib/cfn-parse.ts

@@ -274,6 +274,7 @@ export class CfnParser {
     cfnOptions.updatePolicy = this.parseUpdatePolicy(resourceAttributes.UpdatePolicy);
     cfnOptions.deletionPolicy = this.parseDeletionPolicy(resourceAttributes.DeletionPolicy);
     cfnOptions.updateReplacePolicy = this.parseDeletionPolicy(resourceAttributes.UpdateReplacePolicy);
+    cfnOptions.version = this.parseValue(resourceAttributes.Version);
     cfnOptions.metadata = this.parseValue(resourceAttributes.Metadata);
 
     // handle Condition

packages/@aws-cdk/core/lib/cfn-resource.ts

@@ -300,6 +300,7 @@ export class CfnResource extends CfnRefElement {
             UpdatePolicy: capitalizePropertyNames(this, this.cfnOptions.updatePolicy),
             UpdateReplacePolicy: capitalizePropertyNames(this, this.cfnOptions.updateReplacePolicy),
             DeletionPolicy: capitalizePropertyNames(this, this.cfnOptions.deletionPolicy),
+            Version: this.cfnOptions.version,
             Metadata: ignoreEmpty(this.cfnOptions.metadata),
             Condition: this.cfnOptions.condition && this.cfnOptions.condition.logicalId,
           }, props => {
@@ -429,6 +430,14 @@ export interface ICfnResourceOptions {
    */
   updateReplacePolicy?: CfnDeletionPolicy;
 
+  /**
+   * The version of this resource.
+   * Used only for custom CloudFormation resources.
+   *
+   * @see https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cfn-customresource.html
+   */
+  version?: string;
+
   /**
    * Metadata associated with the CloudFormation resource. This is not the same as the construct metadata which can be added
    * using construct.addMetadata(), but would not appear in the CloudFormation template automatically.