improve public api

packages/overlayscrollbars/src/overlayscrollbars.ts

@@ -8,6 +8,7 @@ import {
   XY,
   TRBL,
   createEventListenerHub,
+  isPlainObject,
 } from 'support';
 import { createStructureSetup, createScrollbarsSetup } from 'setups';
 import { getOptionsDiff, Options, ReadonlyOptions } from 'options';
@@ -31,14 +32,19 @@ import {
   ScrollbarStructure,
 } from 'setups/scrollbarsSetup/scrollbarsSetup.elements';
 
+// Notes:
+// Height intrinsic detection use "content: true" init strategy - or open ticket for custom height intrinsic observer
+
 export interface OverlayScrollbarsStatic {
+  (target: InitializationTarget): OverlayScrollbars | undefined;
   (
     target: InitializationTarget,
-    options?: DeepPartial<Options>,
+    options: DeepPartial<Options>,
     eventListeners?: GeneralInitialEventListeners<EventListenerMap>
   ): OverlayScrollbars;
 
   plugin(plugin: Plugin | Plugin[]): void;
+  valid(osInstance: any): boolean;
   env(): Environment;
 }
 
@@ -147,27 +153,19 @@ export interface OverlayScrollbars {
   off<Name extends keyof EventListenerMap>(name: Name, listener: EventListener<Name>[]): void;
 }
 
-/**
- * Notes:
- * Height intrinsic detection use "content: true" init strategy - or open ticket for custom height intrinsic observer
- */
-
 // eslint-disable-next-line @typescript-eslint/no-redeclare
 export const OverlayScrollbars: OverlayScrollbarsStatic = (
-  target,
-  options?,
-  eventListeners?
-): OverlayScrollbars => {
-  let destroyed = false;
+  target: InitializationTarget,
+  options?: DeepPartial<Options>,
+  eventListeners?: GeneralInitialEventListeners<EventListenerMap>
+) => {
   const { _getDefaultOptions, _addListener: addEnvListener } = getEnvironment();
   const plugins = getPlugins();
   const targetIsElement = isHTMLElement(target);
   const instanceTarget = targetIsElement ? target : target.target;
   const potentialInstance = getInstance(instanceTarget);
-  if (potentialInstance) {
-    return potentialInstance;
-  }
-
+  if (options && !potentialInstance) {
+    let destroyed = false;
     const optionsValidationPlugin = plugins[
       optionsValidationPluginName
     ] as OptionsValidationPluginInstance;
@@ -360,9 +358,16 @@ export const OverlayScrollbars: OverlayScrollbarsStatic = (
     });
 
     return instance.update(true);
+  }
+  return potentialInstance!;
 };
 
 OverlayScrollbars.plugin = addPlugin;
+OverlayScrollbars.valid = (osInstance: any) => {
+  const hasElmsFn = osInstance && (osInstance as OverlayScrollbars).elements;
+  const elements = isFunction(hasElmsFn) && hasElmsFn();
+  return isPlainObject(elements) && !!getInstance(elements.target);
+};
 OverlayScrollbars.env = () => {
   const {
     _nativeScrollbarsSize,

packages/overlayscrollbars/src/plugins/plugins.ts

@@ -12,7 +12,7 @@ const pluginRegistry: Record<string, PluginInstance> = {};
 
 export const getPlugins = () => pluginRegistry;
 
-export const addPlugin = (addedPlugin: Plugin | Plugin[]) => {
+export const addPlugin = (addedPlugin: Plugin | Plugin[]): void => {
   each((isArray(addedPlugin) ? addedPlugin : [addedPlugin]) as Plugin[], (plugin) => {
     const pluginName = keys(plugin)[0];
     pluginRegistry[pluginName] = plugin[pluginName];