app.getAllContext() returns empty object

[piurafunk]

I am attempting to parse some context values from the CDK app. The feature was introduced by #1751

My code snippet is:

const app = new cdk.App();
console.log(app.node.getAllContext());

Which outputs:

{}

However, when I toss a console.log() in Node.getAllContext(), it prints my context variables:

console.log(this._context)

Outputs:

...
  '@aws-cdk/aws-ec2:restrictDefaultSecurityGroup': true,
  '@aws-cdk/aws-apigateway:requestValidatorUniqueId': true,
  longTermStorageBucketArn: 'backups-690e',
  'aws:cdk:enable-path-metadata': true,
  'aws:cdk:enable-asset-metadata': true,
...

Where longTermStorageBucketArn is the context I have passed on command line:

npm run cdk -- -c longTermStorageBucketArn=backups-690e synth

---

I also tested it in the constructor of a Stack object:

console.log('all context', this.node.getAllContext())
// as well as
console.log('all context', scope.node.getAllContext())

both of which produce:

all context {}

---

Is this the intended behavior? I don't seem to understand how to get all context from the app object, whereas app.node.getContext(...) works as expected.

[matt9ucci]

I noticed that the getAllContext method returns the value of defaults arg or {} instead of contexts when the construct is a root node (the scope is undefined).

constructs/src/construct.ts

Lines 248 to 252 in d5eb5ff

	if (typeof defaults === 'undefined') {
	defaults = {};
	}
	if (this.scope === undefined) { return defaults; }

The cdk.App() is a root node. Therefore, its getAllContext method never returns its contexts.