Accessing variables passed into JestCLI - NestJs, Integration Testing

I'd like to use Jest as a testing framework to kick off a suite of Integration tests, and inside each test, I need to access a SALT - which will be passed in via a HTTP request, the same request which will eventually call:

import * as jest from 'jest'

const res = await jest.runCLI(cliArgv, domainPaths)

Without wanting to include the entire cliArgv, some include:

cliArgv['projects'] =['somePathTo/jest-config.js']
cliArgv['globalSetup'] = setupScriptPath
cliArgv['globalTeardown'] = teardownScriptPath
cliArgv['testEnvironment'] = path.join(__dirname, 'custom-jest-environment.js')

I've tried many options to try and pass environment variables passed into the HTTP endpoint, including:

• Creating a Custom Test Environment
• Passing in the variable into the cliArgv['globals'] object
• Using the global.SOME_VARIABLE option.

for context, this is the inside of the custom environment, pretty basic:

import NodeEnvironment from 'jest-environment-node'

class CustomTestEnvironment extends NodeEnvironment {
    globalConfig: any

    constructor(config: any, context: any) {
        super(config, context)
        this.globalConfig = config
    }

    async setup() {
        await super.setup()
        console.log(`this.globalConfig`, this.globalConfig)
    }

    async teardown() {
        await super.teardown()
    }
}

module.exports = CustomTestEnvironment

But what's happening, is no mapper what I pass in, the this.globalConfig log line will only show me {} even if I pass in something like:

globals: {
    SALT: mySalt,
    __DEV__: true
},

It turns out, the process is taking the globals argument from what you've specified inside of the jest.config.ts - which you cannot dynamically pass arguments into.

I am at a loss as to how to pass in a variable passed into the running environment from a HTTP controller, and can flow through the jestCLI() and be used inside a running test.

It turns out that you have to pass in a string into globals that is JSON serialisable.
For example:

globals: JSON.stringify({ __TEST_SALT__: salt, OTHER: 'THIS IS ANOTHER Variable' })