node:timers breaks for Workers without the `nodejs_compat_v2` compatibility flag

[CarmenPopoviciu]

During our regular workerd version bump in workers-sdk, some of our unit/fixture tests started failing with

TypeError: Cannot read properties of undefined (reading 'bind')
 ❯ node-internal:internal_timers:107:53

After some investigation, we realised that changing the compatibility date of the Workers under test to 2024-09-23 (from 2024-01-01) fixes the issue. After further investigation (thank you @vicb ♥ ), we found that the root cause is that the new implementation of node:timers relies on globalThis.setImmediate[1] which is only available with nodejs_compat_v2[2]

This means that the current implementation of node:timers might break users having a compat date before 2024-09-23.

[1]

workerd/src/node/internal/internal_timers.ts

Lines 137 to 139 in b982f8b

	export const setImmediate = globalThis.setImmediate.bind(globalThis);
	export const clearImmediate = globalThis.clearImmediate.bind(globalThis);

[2]

workerd/src/workerd/api/global-scope.h

Lines 387 to 388 in b982f8b

	// An approximation of Node.js setImmediate `Immediate` object.
	// This is used only when the `nodejs_compat_v2` compatibility flag is enabled.

[vicb]

Updating

workerd/src/workerd/api/node/tests/timers-nodejs-test.wd-test

Line 10 in 2bef052

compatibilityDate = "2025-01-09",

to a date before 2024-09-23 will make the test fail.

[anonrig]

Thanks for reporting. I've opened a PR that addresses this issue.