sharedRegistryIfInstalled

Read-only resolver: returns the shared integration registry if one is already installed on window.OCA.OpenRegister.integrations, else null. Never mutates the global — a bare stub queue does not count as installed.

useIntegrationRegistry uses this for its default so a consuming app reads the same registry OpenRegister's bootstrap populated, while falling back to its own module singleton when no global is installed (standalone use, unit tests) — which keeps tests isolated since reading never installs.

import { sharedRegistryIfInstalled } from '@conduction/nextcloud-vue'

const shared = sharedRegistryIfInstalled()   // registry instance or null

Signature

sharedRegistryIfInstalled()            // read window
sharedRegistryIfInstalled(fakeWindow)  // read a test double

Contrast with getSharedRegistry, which installs the singleton when none is present.