Can't read context in aws cdk construct when unit testing

❓ General Issue

Can’t read context in aws cdk construct when unit testing Here is the type script code in cdk constuct:

const ENV_NAME = this.node.tryGetContext("ENV_NAME") ?
this.node.tryGetContext("ENV_NAME") : ``;
        if (_.isEmpty(ENV_NAME)) {
            throw new Error('ENV_NAME context is required...')
        }

Following is the error when unit testing from my jest unit test after run…

FAIL test/cdk.predeploy.test.ts ✕ Empty Stack (5ms)

● Empty Stack

ENV_NAME context is required...

Need help! Thanks.

The Question

Environment

• CDK CLI Version:
• Module Version:
• OS:
• Language:

Other information

[bbrfkr]

I hope to load context of cdk.json when npm test run!

[msmjack]

I never figured out how to do this with some of my nested context values, but I did get my testing to work in Python when I refactored like this. May not be the best option for you, but it works.

def my_method()
    app = core.App()

    app.node.try_get_context("thing")
    app.node.try_get_context("thing2")

And the mocking…

self.expected_app = MagicMock()
self.mock_app = patch("aws_cdk.core.App")
self.mock_app.return_value = self.expected_app
self.expected_app.node.try_get_context.side_effect = [
    "thing",
    "thing2"
]