How to trace jest with custom environment

[lughino]

Hi there,
I need to use a custom environment as I need a newer version of jsdom, so I imported the new @jest/environment-jsdom-abstract package and created a custom environment that extends from that class:

const JSDOM = require('jsdom');
const BaseEnv = require('@jest/environment-jsdom-abstract').default;

class JSDOMEnvironment extends BaseEnv {
  constructor(config, context) {
    super(config, context, JSDOM);
  }
}

module.exports = JSDOMEnvironment;
module.exports.default = JSDOMEnvironment;

Unfortunately, I did not get that working. I always get this error:

/Users/lughino/ui/node_modules/dd-trace/packages/datadog-plugin-jest/src/index.js:228
      this.testSuiteSpan.setTag(TEST_STATUS, status)
                         ^

TypeError: Cannot read properties of undefined (reading 'setTag')
    at /Users/lughino/ui/node_modules/dd-trace/packages/datadog-plugin-jest/src/index.js:228:26
    at Subscription._handler (/Users/lughino/ui/node_modules/dd-trace/packages/dd-trace/src/plugins/plugin.js:14:9)
    at Channel.publish (node:diagnostics_channel:56:9)
    at /Users/lughino/ui/node_modules/dd-trace/packages/datadog-instrumentations/src/jest.js:591:27
    at runTestInternal (/Users/lughino/ui/node_modules/jest-runner/build/runTest.js:367:16)
    at runTest (/Users/lughino/ui/node_modules/jest-runner/build/runTest.js:444:34)

To initiate the dd-trace I tried to use the dd-trace/ci/init through NODE_OPTIONS, or simply including it in this test env file like require('dd-trace').init();.
None of my attempts made it work.

The jest settings are:

const baseConfig = {
  testEnvironment: require.resolve('@internal/jest-preset/jsdomEnv.js'),
  testRegex: '\\.test\\.(js|tsx?)$',
  testMatch: null,
}

If I switch to testEnvironment: 'jsdom' everything works properly.
I also tried to copy the exact content of the old jest-environment-jsdom package inside this custom file but I always get the same error.
It seems like there is some sort of logic around those test environments that prevents me from using tracing in a custom environment.

Any help would be very appreciated

[juan-fernandez]

hey @lughino ! Thanks for the report.

My first thought was that you could extend directly from jest-environment-jsdom (as they with node in the jest docs) but from what I see in the source, JSDOM is hardcoded: https://github.com/jestjs/jest/blob/9113f44b459f96db31e5ad3811d4d8b07f79e54f/packages/jest-environment-jsdom/src/index.ts#L17, so that's not an option for you.

Sadly I don't think there's any workaround for you, as we only monkey patch jest-environment-jsdom and jest-environment-node:

dd-trace-js/packages/datadog-instrumentations/src/jest.js

Lines 296 to 304 in a60bd24

	addHook({
	name: 'jest-environment-node',
	versions: ['>=24.8.0']
	}, getTestEnvironment)
	addHook({
	name: 'jest-environment-jsdom',
	versions: ['>=24.8.0']
	}, getTestEnvironment)

This said, I think adding support for @jest/environment-jsdom-abstract wouldn't be too hard (famous last words). Would you be interesting in contributing the change? I can help 😄