use ember-auto-import to import showdown

index.js

@@ -1,87 +1,5 @@
-/* eslint-disable prettier/prettier */
 'use strict';
 
-const path = require('path');
-const semver = require('semver');
-const funnel = require('broccoli-funnel');
-const stringReplace = require('broccoli-string-replace');
-const UnwatchedDir = require('broccoli-source').UnwatchedDir;
-
 module.exports = {
   name: require('./package').name,
-
-  included() {
-    this._super.included.apply(this, arguments);
-
-    this.import('vendor/showdown.js', {
-      using: [{ transformation: 'amd', as: 'showdown' }]
-    });
-  },
-
-  findModulePath(basedir) {
-    try {
-      let resolve = require('resolve');
-
-      return path.dirname(resolve.sync('showdown', { basedir: basedir }));
-    } catch (_) {
-      try {
-        return path.dirname(require.resolve('showdown'));
-      } catch (e) {
-        if (e.code === 'MODULE_NOT_FOUND') {
-          this.ui.writeLine(
-            `ember-cli-showdown: showdown not installed, be sure you have showdown installed via npm/yarn.`
-          );
-          return;
-        }
-
-        throw e;
-      }
-    }
-  },
-
-  removeSourcemapAnnotation(node) {
-    return stringReplace(node, {
-      files: ['showdown.js'],
-      annotation: 'Remove sourcemap annotation (showdown)',
-      patterns: [
-        {
-          match: /\/\/# sourceMappingURL=showdown.js.map/g,
-          replacement: ''
-        }
-      ]
-    });
-  },
-
-  treeForVendor() {
-    let modulePath = this.findModulePath(this.project.root);
-
-    if (modulePath) {
-      let showdownTree = funnel(new UnwatchedDir(modulePath), {
-        include: ['showdown.js']
-      });
-
-      let pkg = require(path.join(modulePath, '..', 'package.json'));
-
-      if (pkg.version && semver.gt(pkg.version, '1.7.4')) {
-        return this.removeSourcemapAnnotation(showdownTree);
-      }
-
-      /*
-       * The stringReplace forces showdown's loader to use define.amd vs. commonjs/node.
-       * This allows us to use the vendored copy of showdown when the app is eval'd within node (fastboot).
-       * https://github.com/showdownjs/showdown/blob/5d2016c0c1fa2bd722e45b952f1e446c3c870d0f/src/loader.js#L4
-       */
-      return this.removeSourcemapAnnotation(
-        stringReplace(showdownTree, {
-          files: ['showdown.js'],
-          patterns: [
-            {
-              match: /typeof module !== 'undefined'/g,
-              replacement: 'false'
-            }
-          ]
-        })
-      );
-    }
-  }
 };