expect(isPluginRegistryRetired(startupRegistry)).toBe(true);

});

it("falls through from an empty pinned session extension registry to the active surface", () => {

it("keeps empty pinned session extension registries authoritative over active extensions", () => {

const startupRegistry = createEmptyPluginRegistry();

const laterRegistry = createRegistryWithSessionExtension("later", "presence");

const sessionExtensionVersionBeforeSwap = getActivePluginSessionExtensionRegistryVersion();

setActivePluginRegistry(laterRegistry);

expect(getActivePluginSessionExtensionRegistry()).toBe(laterRegistry);

expect(getActivePluginSessionExtensionRegistryVersion()).not.toBe(

expect(getActivePluginSessionExtensionRegistry()).toBe(startupRegistry);

expect(getActivePluginSessionExtensionRegistry()?.sessionExtensions).toHaveLength(0);

expect(getActivePluginSessionExtensionRegistryVersion()).toBe(

sessionExtensionVersionBeforeSwap,

);

});

return created;

}

function countSessionExtensionSurface(registry: PluginRegistry | null): number {

return registry?.sessionExtensions?.length ?? 0;

}

export function pinActivePluginSessionExtensionRegistry(registry: PluginRegistry) {

const previousRegistry = asPluginRegistry(state.sessionExtension.registry);

installSurfaceRegistry(state.sessionExtension, registry, true);

}

export function getActivePluginSessionExtensionRegistry(): PluginRegistry | null {

const surfaceRegistry = asPluginRegistry(state.sessionExtension.registry ?? state.activeRegistry);

if (!state.sessionExtension.pinned) {

return surfaceRegistry;

}

const activeRegistry = asPluginRegistry(state.activeRegistry);

return countSessionExtensionSurface(surfaceRegistry) > 0 ||

countSessionExtensionSurface(activeRegistry) === 0

? surfaceRegistry

: activeRegistry;

return asPluginRegistry(state.sessionExtension.registry ?? state.activeRegistry);

}

export function getActivePluginSessionExtensionRegistryVersion(): number {