detached-construct

Author: mrgrain

packages/aws-cdk-lib/aws-cloudfront/lib/cache-policy.ts

@@ -1,17 +1,17 @@
-import { Construct, Node } from 'constructs';
+import { Construct } from 'constructs';
 import { CachePolicyReference, CfnCachePolicy, ICachePolicyRef } from './cloudfront.generated';
 import {
   Duration,
   Names,
   Resource,
-  ResourceEnvironment,
   Stack,
   Token,
   UnscopedValidationError,
   ValidationError,
   withResolved,
 } from '../../core';
 import { addConstructMetadata } from '../../core/lib/metadata-resource';
+import { DetachedConstruct } from '../../core/lib/private/detached-construct';
 import { propertyInjectable } from '../../core/lib/prop-injectable';
 
 /**
@@ -148,19 +148,14 @@ export class CachePolicy extends Resource implements ICachePolicy {
 
   /** Use an existing managed cache policy. */
   private static fromManagedCachePolicy(managedCachePolicyId: string): ICachePolicy {
-    return new class implements ICachePolicy {
-      public get node(): Node {
-        throw new UnscopedValidationError('The result of fromManagedCachePolicy can not be used in this API');
-      }
-
-      public get env(): ResourceEnvironment {
-        throw new UnscopedValidationError('The result of fromManagedCachePolicy can not be used in this API');
-      }
-
+    return new class extends DetachedConstruct implements ICachePolicy {
       public readonly cachePolicyId = managedCachePolicyId;
       public readonly cachePolicyRef = {
         cachePolicyId: managedCachePolicyId,
       };
+      constructor() {
+        super('The result of fromManagedCachePolicy can not be used in this API');
+      }
     }();
   }
 

packages/aws-cdk-lib/aws-cloudfront/lib/origin-request-policy.ts

@@ -1,7 +1,8 @@
-import { Construct, Node } from 'constructs';
+import { Construct } from 'constructs';
 import { CfnOriginRequestPolicy, IOriginRequestPolicyRef, OriginRequestPolicyReference } from './cloudfront.generated';
-import { Names, Resource, ResourceEnvironment, Token, UnscopedValidationError, ValidationError } from '../../core';
+import { Names, Resource, Token, UnscopedValidationError, ValidationError } from '../../core';
 import { addConstructMetadata } from '../../core/lib/metadata-resource';
+import { DetachedConstruct } from '../../core/lib/private/detached-construct';
 import { propertyInjectable } from '../../core/lib/prop-injectable';
 
 /**
@@ -87,19 +88,14 @@ export class OriginRequestPolicy extends Resource implements IOriginRequestPolic
 
   /** Use an existing managed origin request policy. */
   private static fromManagedOriginRequestPolicy(managedOriginRequestPolicyId: string): IOriginRequestPolicy {
-    return new class implements IOriginRequestPolicy {
-      public get node(): Node {
-        throw new UnscopedValidationError('The result of fromManagedOriginRequestPolicy can not be used in this API');
-      }
-
-      public get env(): ResourceEnvironment {
-        throw new UnscopedValidationError('The result of fromManagedOriginRequestPolicy can not be used in this API');
-      }
-
+    return new class extends DetachedConstruct implements IOriginRequestPolicy {
       public readonly originRequestPolicyId = managedOriginRequestPolicyId;
       public readonly originRequestPolicyRef = {
         originRequestPolicyId: managedOriginRequestPolicyId,
       };
+      constructor() {
+        super('The result of fromManagedOriginRequestPolicy can not be used in this API');
+      }
     }();
   }
 

packages/aws-cdk-lib/aws-cloudfront/lib/response-headers-policy.ts

@@ -1,11 +1,12 @@
-import { Construct, Node } from 'constructs';
+import { Construct } from 'constructs';
 import {
   CfnResponseHeadersPolicy,
   IResponseHeadersPolicyRef,
   ResponseHeadersPolicyReference,
 } from './cloudfront.generated';
-import { Duration, Names, Resource, ResourceEnvironment, Token, UnscopedValidationError, ValidationError, withResolved } from '../../core';
+import { Duration, Names, Resource, Token, ValidationError, withResolved } from '../../core';
 import { addConstructMetadata } from '../../core/lib/metadata-resource';
+import { DetachedConstruct } from '../../core/lib/private/detached-construct';
 import { propertyInjectable } from '../../core/lib/prop-injectable';
 
 /**
@@ -109,19 +110,14 @@ export class ResponseHeadersPolicy extends Resource implements IResponseHeadersP
   }
 
   private static fromManagedResponseHeadersPolicy(managedResponseHeadersPolicyId: string): IResponseHeadersPolicy {
-    return new class implements IResponseHeadersPolicy {
-      public get node(): Node {
-        throw new UnscopedValidationError('The result of fromManagedResponseHeadersPolicy can not be used in this API');
-      }
-
-      public get env(): ResourceEnvironment {
-        throw new UnscopedValidationError('The result of fromManagedResponseHeadersPolicy can not be used in this API');
-      }
-
+    return new class extends DetachedConstruct implements IResponseHeadersPolicy {
       public readonly responseHeadersPolicyId = managedResponseHeadersPolicyId;
       public readonly responseHeadersPolicyRef = {
         responseHeadersPolicyId: managedResponseHeadersPolicyId,
       };
+      constructor() {
+        super('The result of fromManagedResponseHeadersPolicy can not be used in this API');
+      }
     };
   }
 

packages/aws-cdk-lib/aws-codepipeline-actions/lib/elastic-beanstalk/deploy-action.ts

@@ -1,6 +1,7 @@
-import { Construct, Node } from 'constructs';
+import { Construct } from 'constructs';
 import * as codepipeline from '../../../aws-codepipeline';
-import { Aws, ResourceEnvironment, UnscopedValidationError } from '../../../core';
+import { Aws } from '../../../core';
+import { DetachedConstruct } from '../../../core/lib/private/detached-construct';
 import { Action } from '../action';
 import { deployArtifactBounds } from '../common';
 
@@ -53,16 +54,13 @@ export class ElasticBeanstalkDeployAction extends Action {
     // it doesn't seem we can scope this down further for the codepipeline action.
 
     const policyArn = `arn:${Aws.PARTITION}:iam::aws:policy/AdministratorAccess-AWSElasticBeanstalk`;
-    options.role.addManagedPolicy({
-      get node(): Node {
-        throw new UnscopedValidationError('This object can not be used in this API');
-      },
-      get env(): ResourceEnvironment {
-        throw new UnscopedValidationError('This object can not be used in this API');
-      },
-      managedPolicyArn: policyArn,
-      managedPolicyRef: { policyArn },
-    });
+    options.role.addManagedPolicy(new class extends DetachedConstruct {
+      managedPolicyArn = policyArn;
+      managedPolicyRef = { policyArn };
+      constructor() {
+        super('This object can not be used in this API');
+      }
+    }());
 
     // the Action's Role needs to read from the Bucket to get artifacts
     options.bucket.grantRead(options.role);

packages/aws-cdk-lib/aws-iam/lib/managed-policy.ts

@@ -1,4 +1,4 @@
-import { Construct, Node } from 'constructs';
+import { Construct } from 'constructs';
 import {
   CfnManagedPolicy,
   IGroupRef,
@@ -13,9 +13,10 @@ import { AddToPrincipalPolicyResult, ArnPrincipal, IGrantable, IPrincipal, Princ
 import { undefinedIfEmpty } from './private/util';
 import { IRole } from './role';
 import { IUser } from './user';
-import { Arn, ArnFormat, Aws, Resource, ResourceEnvironment, Stack, UnscopedValidationError, ValidationError, Lazy } from '../../core';
+import { Arn, ArnFormat, Aws, Resource, Stack, ValidationError, Lazy } from '../../core';
 import { getCustomizeRolesConfig, PolicySynthesizer } from '../../core/lib/helpers-internal';
 import { addConstructMetadata, MethodMetadata } from '../../core/lib/metadata-resource';
+import { DetachedConstruct } from '../../core/lib/private/detached-construct';
 import { propertyInjectable } from '../../core/lib/prop-injectable';
 
 /**
@@ -179,7 +180,7 @@ export class ManagedPolicy extends Resource implements IManagedPolicy, IGrantabl
    * prefix when constructing this object.
    */
   public static fromAwsManagedPolicyName(managedPolicyName: string): IManagedPolicy {
-    class AwsManagedPolicy implements IManagedPolicy {
+    class AwsManagedPolicy extends DetachedConstruct implements IManagedPolicy {
       public readonly managedPolicyArn = Arn.format({
         partition: Aws.PARTITION,
         service: 'iam',
@@ -188,17 +189,14 @@ export class ManagedPolicy extends Resource implements IManagedPolicy, IGrantabl
         resource: 'policy',
         resourceName: managedPolicyName,
       });
+      constructor() {
+        super('The result of fromAwsManagedPolicyName can not be used in this API');
+      }
       public get managedPolicyRef(): ManagedPolicyReference {
         return {
           policyArn: this.managedPolicyArn,
         };
       }
-      public get node(): Node {
-        throw new UnscopedValidationError('The result of fromAwsManagedPolicyName can not be used in this API');
-      }
-      public get env(): ResourceEnvironment {
-        throw new UnscopedValidationError('The result of fromAwsManagedPolicyName can not be used in this API');
-      }
     }
     return new AwsManagedPolicy();
   }

packages/aws-cdk-lib/core/lib/private/detached-construct.ts

@@ -0,0 +1,46 @@
+import { Construct, IConstruct } from 'constructs';
+import type { ResourceEnvironment } from '../environment';
+import { UnscopedValidationError } from '../errors';
+
+const CONSTRUCT_SYM = Symbol.for('constructs.Construct');
+
+/**
+ * Base class for detached constructs that throw UnscopedValidationError
+ * when accessing node, env, or with() methods.
+ *
+ * This is used by legacy APIs like ManagedPolicy.fromAwsManagedPolicyName() and
+ * CloudFront policy imports that return construct-like objects without requiring
+ * a scope parameter. These APIs predate modern CDK patterns and cannot be changed
+ * without breaking existing customer code.
+ *
+ * DO NOT USE for new code. New APIs should require a scope parameter.
+ *
+ * @internal
+ */
+export abstract class DetachedConstruct extends Construct implements IConstruct {
+  private readonly errorMessage: string;
+
+  constructor(errorMessage: string) {
+    super(null as any, undefined as any);
+
+    this.errorMessage = errorMessage;
+
+    // Use Object.defineProperty to override 'node' property instead of a getter
+    // to avoid TS2611 error (property vs accessor conflict with base class)
+    Object.defineProperty(this, 'node', {
+      get() { throw new UnscopedValidationError(errorMessage); },
+    });
+
+    // Despite extending Construct, DetachedConstruct doesn't work like one.
+    // So we try to not pretend that this is a construct as much as possible.
+    Object.defineProperty(this, CONSTRUCT_SYM, {
+      value: false,
+      enumerable: false,
+      writable: false,
+    });
+  }
+
+  public get env(): ResourceEnvironment {
+    throw new UnscopedValidationError(this.errorMessage);
+  }
+}

packages/aws-cdk-lib/core/test/private/detached-construct.test.ts

@@ -0,0 +1,31 @@
+import { Construct } from 'constructs';
+import { UnscopedValidationError } from '../../lib/errors';
+import { DetachedConstruct } from '../../lib/private/detached-construct';
+
+class TestDetachedConstruct extends DetachedConstruct {
+  constructor(message: string) {
+    super(message);
+  }
+}
+
+describe('DetachedConstruct', () => {
+  test('throws UnscopedValidationError when accessing node', () => {
+    const construct = new TestDetachedConstruct('test error message');
+
+    expect(() => construct.node).toThrow(UnscopedValidationError);
+    expect(() => construct.node).toThrow('test error message');
+  });
+
+  test('throws UnscopedValidationError when accessing env', () => {
+    const construct = new TestDetachedConstruct('test error message');
+
+    expect(() => construct.env).toThrow(UnscopedValidationError);
+    expect(() => construct.env).toThrow('test error message');
+  });
+
+  test('returns false for Construct.isConstruct', () => {
+    const construct = new TestDetachedConstruct('test error message');
+
+    expect(Construct.isConstruct(construct)).toBe(false);
+  });
+});