refactor: removing module federation-based plugins

The code removed in this commit existed to load plugins via webpack module federation.  It was never intended to be included in this version of plugins.  We don’t intend to use module federation, and are instead investing in a micro-frontend framework like Piral.

src/plugins/Plugin.jsx

@@ -1,11 +1,10 @@
 import React from 'react';
 
-import PluginComponent from './PluginComponent';
 import PluginIframe from './PluginIframe';
 import PluginErrorBoundary from './PluginErrorBoundary';
 
 import {
-  COMPONENT_PLUGIN, IFRAME_PLUGIN,
+  IFRAME_PLUGIN,
 } from './data/constants';
 import { pluginShape } from './data/shapes';
 
@@ -16,11 +15,6 @@ export default function Plugin({ plugin, ...props }) {
 
   let renderer = null;
   switch (plugin.type) {
-    case COMPONENT_PLUGIN:
-      renderer = (
-        <PluginComponent plugin={plugin} {...props} />
-      );
-      break;
     case IFRAME_PLUGIN:
       renderer = (
         <PluginIframe plugin={plugin} {...props} />

src/plugins/data/constants.js

@@ -1,10 +1,5 @@
-// These are intended to represent three different plugin types.  They're not fully used yet.
-
-// Different plugins of different types would have different loading functionality.
-export const COMPONENT_PLUGIN = 'COMPONENT_PLUGIN'; // loads JS script then loads react component from its exports
-export const SCRIPT_PLUGIN = 'SCRIPT_PLUGIN'; // loads JS script
+// TODO: We expect other plugin types to be added here, such as LTI_PLUGIN and BUILD_TIME_PLUGIN.
 export const IFRAME_PLUGIN = 'IFRAME_PLUGIN'; // loads iframe at the URL, rather than loading a JS file.
-export const LTI_PLUGIN = 'LTI_PLUGIN'; // loads LTI iframe at the URL, rather than loading a JS file.
 
 // Plugin lifecycle events
 export const PLUGIN_MOUNTED = 'PLUGIN_MOUNTED';

src/plugins/data/hooks.js

@@ -1,21 +1,9 @@
 import {
-  lazy, useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState,
+  useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState,
 } from 'react';
-import { loadPluginComponent, unloadDynamicScript } from './utils';
 import { getConfig } from '../../config';
 import { PLUGIN_MOUNTED, PLUGIN_READY, PLUGIN_UNMOUNTED } from './constants';
 
-export function useDynamicPluginComponent(plugin) {
-  // When this component unmounts, see if we should unload the script that provided it.
-  // Note that this is not guaranteed to unload the script if other consumers are still using one
-  // of its exports.
-  useEffect(() => () => {
-    unloadDynamicScript(plugin.url);
-  }, []);
-
-  return lazy(loadPluginComponent(plugin));
-}
-
 export function usePluginSlot(id) {
   if (getConfig().plugins[id] !== undefined) {
     return getConfig().plugins[id];

src/plugins/data/shapes.js

@@ -1,12 +1,12 @@
 /* eslint-disable import/prefer-default-export */
 import PropTypes from 'prop-types';
-import { COMPONENT_PLUGIN, IFRAME_PLUGIN } from './constants';
+import { IFRAME_PLUGIN } from './constants';
 
 export const pluginShape = PropTypes.shape({
   scope: PropTypes.string,
   module: PropTypes.string,
   url: PropTypes.string.isRequired,
-  type: PropTypes.oneOf([COMPONENT_PLUGIN, IFRAME_PLUGIN]).isRequired,
+  type: PropTypes.oneOf([IFRAME_PLUGIN]).isRequired,
   // This is a place for us to put any generic props we want to pass to the component.  We need it.
   props: PropTypes.object, // eslint-disable-line react/forbid-prop-types
 });

src/plugins/index.js

@@ -1,4 +1,6 @@
-export { useDynamicPluginComponent, usePluginSlot } from './data/hooks';
+export {
+  usePluginSlot,
+} from './data/hooks';
 export {
   default as Plugin,
 } from './Plugin';
@@ -9,6 +11,5 @@ export {
   default as PluginSlot,
 } from './PluginSlot';
 export {
-  COMPONENT_PLUGIN,
   IFRAME_PLUGIN,
 } from './data/constants';