diff --git a/.gitignore b/.gitignore
index c63f5b0..3ada55b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -89,3 +89,6 @@ vendor/
 /css/
 /templates/
 /assets/
+
+# Test-theme
+/test/website/themes/mantra
diff --git a/.gulp/Settings.ts b/.gulp/Settings.ts
index 415b707..9a218f9 100644
--- a/.gulp/Settings.ts
+++ b/.gulp/Settings.ts
@@ -35,6 +35,16 @@ export class Settings
      */
     private libraryPath = "javascript";
 
+    /**
+     * The path to the test-directory.
+     */
+    private testPath = "test";
+
+    /**
+     * The path to the test-website.
+     */
+    private testWebsitePath = "website";
+
     /**
      * Initializes a new instance of the `Settings` class.
      *
@@ -123,4 +133,32 @@ export class Settings
     {
         return this.RootPath(this.libraryPath, ...path);
     }
+
+    /**
+     * Creates a path relative to the test-directory.
+     *
+     * @param path
+     * The path to join.
+     *
+     * @returns
+     * The joined path.
+     */
+    public TestPath(...path: string[])
+    {
+        return this.RootPath(this.testPath, ...path);
+    }
+
+    /**
+     * Creates a path relative to the test-website.
+     *
+     * @param path
+     * The path to join.
+     *
+     * @returns
+     * The joined path.
+     */
+    public TestWebsitePath(...path: string[])
+    {
+        return this.TestPath(this.testWebsitePath, ...path);
+    }
 }
\ No newline at end of file
diff --git a/.gulp/TaskFunction.ts b/.gulp/TaskFunction.ts
index d10e90d..f3f46b8 100644
--- a/.gulp/TaskFunction.ts
+++ b/.gulp/TaskFunction.ts
@@ -6,7 +6,7 @@ import { TaskFunction } from "gulp";
 declare global
 {
     // tslint:disable-next-line: completed-docs
-    interface Function extends TaskFunction
+    interface Function extends Partial<TaskFunction>
     { }
 }
 
diff --git a/.vscode/extensions.json b/.vscode/extensions.json
index b5fccce..bd441a3 100644
--- a/.vscode/extensions.json
+++ b/.vscode/extensions.json
@@ -4,6 +4,7 @@
 
 	// List of extensions which should be recommended for users of this workspace.
 	"recommendations": [
+		"adrianhumphreys.silverstripe",
 		"ms-vscode.vscode-typescript-tslint-plugin",
 		"ms-vscode-remote.remote-containers"
 	],
diff --git a/composer.json b/composer.json
index 882ed08..b756985 100644
--- a/composer.json
+++ b/composer.json
@@ -53,7 +53,9 @@
     "extra": {
         "scripts-dev": {
             "post-install-cmd": [
-                "npm install"
+                "npm install",
+                "@initialize",
+                "composer --working-dir=./test/website install"
             ]
         }
     }
diff --git a/composer.lock b/composer.lock
index e94ad04..c4714bb 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "22068a23fc6b360469aeccc3a344ead6",
+    "content-hash": "848468c4f4ad00ed3629fa3cbf2bea5b",
     "packages": [],
     "packages-dev": [
         {
diff --git a/gulpfile.ts b/gulpfile.ts
index 37a11e4..1f33f28 100644
--- a/gulpfile.ts
+++ b/gulpfile.ts
@@ -1,7 +1,8 @@
 import browserify = require("browserify");
 import log = require("fancy-log");
-import gulp = require("gulp");
+import FileSystem = require("fs-extra");
 import { TaskFunction } from "gulp";
+import gulp = require("gulp");
 import gulpIf = require("gulp-if");
 import terser = require("gulp-terser");
 import merge = require("merge-stream");
@@ -78,9 +79,28 @@ let settings = new Settings(options["target"]);
 /**
  * Initializes the project.
  */
-export function Initialize(done: () => void)
+export async function Initialize()
 {
-    done();
+    let directories = [
+        "javascript",
+        "css",
+        "templates",
+        "assets"
+    ];
+
+    let themePath = settings.TestWebsitePath("themes", Path.basename(settings.RootPath()));
+
+    for (let directory of directories)
+    {
+        await FileSystem.emptyDir(settings.RootPath(directory));
+    }
+
+    if (await FileSystem.pathExists(themePath))
+    {
+        await FileSystem.remove(themePath);
+    }
+
+    await require("create-symlink")(settings.RootPath(), themePath, { type: "junction" });
 }
 
 Initialize.description = "Initializes the project.";
@@ -132,7 +152,7 @@ export async function Build()
         log.info(watchStartMessage);
     }
 
-    Library();
+    await Library();
 }
 
 /**
diff --git a/package-lock.json b/package-lock.json
index c6d74dd..6a1cba9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -66,6 +66,15 @@
       "integrity": "sha512-31Dt9JaGfHretvwVxCBrCFL5iC9MQ3zOXpu+8C4qzW0cxc5rJJVGxB5c/vZ+wmeTk/JjPz/D0gv8BZ+Ip6iCqQ==",
       "dev": true
     },
+    "@types/fs-extra": {
+      "version": "8.0.0",
+      "resolved": "https://registry.npmjs.org/@types/fs-extra/-/fs-extra-8.0.0.tgz",
+      "integrity": "sha512-bCtL5v9zdbQW86yexOlXWTEGvLNqWxMFyi7gQA7Gcthbezr2cPSOb8SkESVKA937QD5cIwOFLDFt0MQoXOEr9Q==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*"
+      }
+    },
     "@types/glob": {
       "version": "7.1.1",
       "resolved": "https://registry.npmjs.org/@types/glob/-/glob-7.1.1.tgz",
@@ -1220,6 +1229,17 @@
         "sha.js": "^2.4.8"
       }
     },
+    "create-symlink": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/create-symlink/-/create-symlink-1.0.0.tgz",
+      "integrity": "sha1-QNOKcRdnMiNFdi+Q+NBs8nJiAdc=",
+      "dev": true,
+      "requires": {
+        "graceful-fs": "^4.1.11",
+        "inspect-with-kind": "^1.0.0",
+        "is-plain-obj": "^1.1.0"
+      }
+    },
     "crypto-browserify": {
       "version": "3.12.0",
       "resolved": "https://registry.npmjs.org/crypto-browserify/-/crypto-browserify-3.12.0.tgz",
@@ -1817,6 +1837,17 @@
         "map-cache": "^0.2.2"
       }
     },
+    "fs-extra": {
+      "version": "8.1.0",
+      "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-8.1.0.tgz",
+      "integrity": "sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==",
+      "dev": true,
+      "requires": {
+        "graceful-fs": "^4.2.0",
+        "jsonfile": "^4.0.0",
+        "universalify": "^0.1.0"
+      }
+    },
     "fs-mkdirp-stream": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/fs-mkdirp-stream/-/fs-mkdirp-stream-1.0.0.tgz",
@@ -2780,6 +2811,15 @@
         "xtend": "^4.0.0"
       }
     },
+    "inspect-with-kind": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/inspect-with-kind/-/inspect-with-kind-1.0.5.tgz",
+      "integrity": "sha512-MAQUJuIo7Xqk8EVNP+6d3CKq9c80hi4tjIbIAT6lmGW9W6WzlHiu9PS8uSuUYU+Do+j1baiFp3H25XEVxDIG2g==",
+      "dev": true,
+      "requires": {
+        "kind-of": "^6.0.2"
+      }
+    },
     "interpret": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/interpret/-/interpret-1.2.0.tgz",
@@ -2938,6 +2978,12 @@
         }
       }
     },
+    "is-plain-obj": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/is-plain-obj/-/is-plain-obj-1.1.0.tgz",
+      "integrity": "sha1-caUMhCnfync8kqOQpKA7OfzVHT4=",
+      "dev": true
+    },
     "is-plain-object": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/is-plain-object/-/is-plain-object-2.0.4.tgz",
@@ -3038,6 +3084,15 @@
       "integrity": "sha1-nbe1lJatPzz+8wp1FC0tkwrXJlE=",
       "dev": true
     },
+    "jsonfile": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
+      "integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
+      "dev": true,
+      "requires": {
+        "graceful-fs": "^4.1.6"
+      }
+    },
     "jsonify": {
       "version": "0.0.0",
       "resolved": "https://registry.npmjs.org/jsonify/-/jsonify-0.0.0.tgz",
@@ -3136,6 +3191,14 @@
         "pify": "^2.0.0",
         "pinkie-promise": "^2.0.0",
         "strip-bom": "^2.0.0"
+      },
+      "dependencies": {
+        "pify": {
+          "version": "2.3.0",
+          "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
+          "integrity": "sha1-7RQaasBDqEnqWISY59yosVMw6Qw=",
+          "dev": true
+        }
       }
     },
     "lodash.memoize": {
@@ -3720,6 +3783,14 @@
         "graceful-fs": "^4.1.2",
         "pify": "^2.0.0",
         "pinkie-promise": "^2.0.0"
+      },
+      "dependencies": {
+        "pify": {
+          "version": "2.3.0",
+          "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
+          "integrity": "sha1-7RQaasBDqEnqWISY59yosVMw6Qw=",
+          "dev": true
+        }
       }
     },
     "pbkdf2": {
@@ -3735,12 +3806,6 @@
         "sha.js": "^2.4.8"
       }
     },
-    "pify": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
-      "integrity": "sha1-7RQaasBDqEnqWISY59yosVMw6Qw=",
-      "dev": true
-    },
     "pinkie": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/pinkie/-/pinkie-2.0.4.tgz",
@@ -4891,6 +4956,12 @@
         "through2-filter": "^3.0.0"
       }
     },
+    "universalify": {
+      "version": "0.1.2",
+      "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
+      "integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
+      "dev": true
+    },
     "unset-value": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/unset-value/-/unset-value-1.0.0.tgz",
diff --git a/package.json b/package.json
index bd78b2a..4c9e754 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,7 @@
     "@types/bootstrap": "^4.3.1",
     "@types/browserify": "^12.0.36",
     "@types/fancy-log": "^1.3.1",
+    "@types/fs-extra": "^8.0.0",
     "@types/gulp": "^4.0.6",
     "@types/gulp-if": "0.0.33",
     "@types/gulp-terser": "^1.2.0",
@@ -23,7 +24,9 @@
     "@types/watchify": "^3.7.4",
     "bootstrap": "^4.3.1",
     "browserify": "^16.5.0",
+    "create-symlink": "^1.0.0",
     "fancy-log": "^1.3.3",
+    "fs-extra": "^8.1.0",
     "gulp": "^4.0.2",
     "gulp-if": "^3.0.0",
     "gulp-terser": "^1.2.0",
diff --git a/test/website/app/_config/theme.yml b/test/website/app/_config/theme.yml
index e1184e7..93d2496 100644
--- a/test/website/app/_config/theme.yml
+++ b/test/website/app/_config/theme.yml
@@ -3,6 +3,6 @@ Name: mytheme
 ---
 SilverStripe\View\SSViewer:
   themes:
+    - 'mantra'
     - '$public'
-    - 'simple'
     - '$default'
diff --git a/test/website/composer.json b/test/website/composer.json
index a69b88a..7bd7885 100644
--- a/test/website/composer.json
+++ b/test/website/composer.json
@@ -12,6 +12,11 @@
         "phpunit/phpunit": "^5.7"
     },
     "extra": {
+        "expose": [
+            "themes/mantra/assets",
+            "themes/mantra/css",
+            "themes/mantra/javascript"
+        ],
         "resources-dir": "_resources",
         "project-files-installed": [
             "app/.htaccess",
diff --git a/test/website/composer.lock b/test/website/composer.lock
index 75f7c42..8d1225d 100644
--- a/test/website/composer.lock
+++ b/test/website/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "7ff31cbd9aa5ee75c9624d2bb8c3bc5f",
+    "content-hash": "0ab3e4aaf71526993c3dbb3ea6179605",
     "packages": [
         {
             "name": "bramus/ansi-php",
@@ -2216,16 +2216,16 @@
         },
         {
             "name": "symfony/cache",
-            "version": "v3.4.31",
+            "version": "v3.4.32",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/cache.git",
-                "reference": "6a9cc3ed7f61c6c2bc042d0594cdb807b6fea62c"
+                "reference": "5c7bd827617fcb9b13e04e423c31c0fb0bcf0160"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/cache/zipball/6a9cc3ed7f61c6c2bc042d0594cdb807b6fea62c",
-                "reference": "6a9cc3ed7f61c6c2bc042d0594cdb807b6fea62c",
+                "url": "https://api.github.com/repos/symfony/cache/zipball/5c7bd827617fcb9b13e04e423c31c0fb0bcf0160",
+                "reference": "5c7bd827617fcb9b13e04e423c31c0fb0bcf0160",
                 "shasum": ""
             },
             "require": {
@@ -2282,20 +2282,20 @@
                 "caching",
                 "psr6"
             ],
-            "time": "2019-08-26T07:52:58+00:00"
+            "time": "2019-09-29T21:19:44+00:00"
         },
         {
             "name": "symfony/config",
-            "version": "v3.4.31",
+            "version": "v3.4.32",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/config.git",
-                "reference": "24a60c0d7ad98a0fa5d1f892e9286095a389404f"
+                "reference": "717ad66b5257e9752ae3c5722b5810bb4c40b236"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/config/zipball/24a60c0d7ad98a0fa5d1f892e9286095a389404f",
-                "reference": "24a60c0d7ad98a0fa5d1f892e9286095a389404f",
+                "url": "https://api.github.com/repos/symfony/config/zipball/717ad66b5257e9752ae3c5722b5810bb4c40b236",
+                "reference": "717ad66b5257e9752ae3c5722b5810bb4c40b236",
                 "shasum": ""
             },
             "require": {
@@ -2346,11 +2346,11 @@
             ],
             "description": "Symfony Config Component",
             "homepage": "https://symfony.com",
-            "time": "2019-08-26T07:52:57+00:00"
+            "time": "2019-09-19T15:32:51+00:00"
         },
         {
             "name": "symfony/filesystem",
-            "version": "v4.3.4",
+            "version": "v4.3.5",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/filesystem.git",
@@ -2400,16 +2400,16 @@
         },
         {
             "name": "symfony/finder",
-            "version": "v3.4.31",
+            "version": "v3.4.32",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/finder.git",
-                "reference": "1fcad80b440abcd1451767349906b6f9d3961d37"
+                "reference": "2b6a666d6ff7fb65d10b97d817c8e7930944afb9"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/finder/zipball/1fcad80b440abcd1451767349906b6f9d3961d37",
-                "reference": "1fcad80b440abcd1451767349906b6f9d3961d37",
+                "url": "https://api.github.com/repos/symfony/finder/zipball/2b6a666d6ff7fb65d10b97d817c8e7930944afb9",
+                "reference": "2b6a666d6ff7fb65d10b97d817c8e7930944afb9",
                 "shasum": ""
             },
             "require": {
@@ -2445,7 +2445,7 @@
             ],
             "description": "Symfony Finder Component",
             "homepage": "https://symfony.com",
-            "time": "2019-08-14T09:39:58+00:00"
+            "time": "2019-09-01T21:32:23+00:00"
         },
         {
             "name": "symfony/polyfill-apcu",
@@ -2686,16 +2686,16 @@
         },
         {
             "name": "symfony/yaml",
-            "version": "v3.4.31",
+            "version": "v3.4.32",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/yaml.git",
-                "reference": "3dc414b7db30695bae671a1d86013d03f4ae9834"
+                "reference": "768f817446da74a776a31eea335540f9dcb53942"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/yaml/zipball/3dc414b7db30695bae671a1d86013d03f4ae9834",
-                "reference": "3dc414b7db30695bae671a1d86013d03f4ae9834",
+                "url": "https://api.github.com/repos/symfony/yaml/zipball/768f817446da74a776a31eea335540f9dcb53942",
+                "reference": "768f817446da74a776a31eea335540f9dcb53942",
                 "shasum": ""
             },
             "require": {
@@ -2741,7 +2741,7 @@
             ],
             "description": "Symfony Yaml Component",
             "homepage": "https://symfony.com",
-            "time": "2019-08-20T13:31:17+00:00"
+            "time": "2019-09-10T10:38:46+00:00"
         },
         {
             "name": "webonyx/graphql-php",