diff --git a/src/browser/pages/vscode.ts b/src/browser/pages/vscode.ts
index 128df2c4..61648dd3 100644
--- a/src/browser/pages/vscode.ts
+++ b/src/browser/pages/vscode.ts
@@ -24,13 +24,13 @@ type NlsConfiguration = {
  * Helper function to create the path to the bundle
  * for getNlsConfiguration.
  */
-export function createBundlePath(_resolvedLanguagePackCoreLocation: string, bundle: string) {
+export function createBundlePath(_resolvedLanguagePackCoreLocation: string | undefined, bundle: string) {
   // NOTE@jsjoeio - this comment was here before me
   // Refers to operating systems that use a different path separator.
   // Probably just Windows but we're not sure if "/" breaks on Windows
   // so we'll leave it alone for now.
   // FIXME: Only works if path separators are /.
-  return _resolvedLanguagePackCoreLocation + "/" + bundle.replace(/\//g, "!") + ".nls.json"
+  return (_resolvedLanguagePackCoreLocation || "") + "/" + bundle.replace(/\//g, "!") + ".nls.json"
 }
 
 /**
@@ -72,20 +72,22 @@ export function getNlsConfiguration(_document: Document, base: string) {
 
     type LoadBundleCallback = (_: undefined, result?: string) => void
 
-    nlsConfig.loadBundle = (bundle: string, _language: string, cb: LoadBundleCallback): void => {
+    nlsConfig.loadBundle = async (bundle: string, _language: string, cb: LoadBundleCallback): Promise<void> => {
       const result = bundles[bundle]
+
       if (result) {
         return cb(undefined, result)
       }
-      // FIXME: Only works if path separators are /.
-      const path = createBundlePath(nlsConfig._resolvedLanguagePackCoreLocation || "", bundle)
-      fetch(`${base}/vscode/resource/?path=${encodeURIComponent(path)}`)
-        .then((response) => response.json())
-        .then((json) => {
-          bundles[bundle] = json
-          cb(undefined, json)
-        })
-        .catch(cb)
+
+      try {
+        const path = createBundlePath(nlsConfig._resolvedLanguagePackCoreLocation, bundle)
+        const response = await fetch(`${base}/vscode/resource/?path=${encodeURIComponent(path)}`)
+        const json = await response.json()
+        bundles[bundle] = json
+        return cb(undefined, json)
+      } catch (error) {
+        return cb(error)
+      }
     }
   }
 
diff --git a/test/package.json b/test/package.json
index a23c4d11..4f87bc67 100644
--- a/test/package.json
+++ b/test/package.json
@@ -7,14 +7,15 @@
     "@types/jsdom": "^16.2.6",
     "@types/node-fetch": "^2.5.8",
     "@types/supertest": "^2.0.10",
+    "@types/wtfnode": "^0.7.0",
     "argon2": "^0.28.0",
     "jest": "^26.6.3",
+    "jest-fetch-mock": "^3.0.3",
     "jsdom": "^16.4.0",
     "node-fetch": "^2.6.1",
     "playwright": "^1.12.1",
     "supertest": "^6.1.1",
     "ts-jest": "^26.4.4",
-    "@types/wtfnode": "^0.7.0",
     "wtfnode": "^0.9.0"
   },
   "resolutions": {
diff --git a/test/unit/browser/pages/vscode.test.ts b/test/unit/browser/pages/vscode.test.ts
index 99c109bb..2c0d1a38 100644
--- a/test/unit/browser/pages/vscode.test.ts
+++ b/test/unit/browser/pages/vscode.test.ts
@@ -1,6 +1,7 @@
 /**
  * @jest-environment jsdom
  */
+import fetchMock from "jest-fetch-mock"
 import { JSDOM } from "jsdom"
 import {
   getNlsConfiguration,
@@ -20,6 +21,11 @@ describe("vscode", () => {
       // We use underscores to not confuse with global values
       const { window: _window } = new JSDOM()
       _document = _window.document
+      fetchMock.enableMocks()
+    })
+
+    afterEach(() => {
+      fetchMock.resetMocks()
     })
 
     it("should throw an error if no nlsConfigElement", () => {
@@ -60,7 +66,7 @@ describe("vscode", () => {
 
       _document.body.removeChild(mockElement)
     })
-    it("should return have loadBundle property if _resolvedLangaugePackCoreLocation", () => {
+    it("should return and have a loadBundle property if _resolvedLangaugePackCoreLocation", async () => {
       const mockElement = _document.createElement("div")
       const dataSettings = {
         locale: "en",
@@ -76,6 +82,32 @@ describe("vscode", () => {
       expect(nlsConfig._resolvedLanguagePackCoreLocation).not.toBe(undefined)
       expect(nlsConfig.loadBundle).not.toBe(undefined)
 
+      const mockCallbackFn = jest.fn((_, bundle) => {
+        return bundle
+      })
+
+      fetchMock.mockOnce(JSON.stringify({ key: "hello world" }))
+      // Ensure that load bundle works as expected
+      // by mocking the fetch response and checking that the callback
+      // had the expected value
+      await nlsConfig.loadBundle("hello", "en", mockCallbackFn)
+      expect(mockCallbackFn).toHaveBeenCalledTimes(1)
+      expect(mockCallbackFn).toHaveBeenCalledWith(undefined, { key: "hello world" })
+
+      // Call it again to ensure it loads from the cache
+      // it should return the same value
+      await nlsConfig.loadBundle("hello", "en", mockCallbackFn)
+      expect(mockCallbackFn).toHaveBeenCalledTimes(2)
+      expect(mockCallbackFn).toHaveBeenCalledWith(undefined, { key: "hello world" })
+
+      fetchMock.mockReject(new Error("fake error message"))
+      const mockCallbackFn2 = jest.fn((error) => error)
+      // Call it for a different bundle and mock a failed fetch call
+      // to ensure we get the expected error
+      const error = await nlsConfig.loadBundle("goodbye", "es", mockCallbackFn2)
+      expect(error.message).toEqual("fake error message")
+
+      // Clean up
       _document.body.removeChild(mockElement)
     })
   })
@@ -87,6 +119,13 @@ describe("vscode", () => {
       const actual = createBundlePath(_resolvedLangaugePackCoreLocation, bundle)
       expect(actual).toBe(expected)
     })
+    it("should return the correct path (even if _resolvedLangaugePackCoreLocation is undefined)", () => {
+      const _resolvedLangaugePackCoreLocation = undefined
+      const bundle = "/bundle.js"
+      const expected = "/!bundle.js.nls.json"
+      const actual = createBundlePath(_resolvedLangaugePackCoreLocation, bundle)
+      expect(actual).toBe(expected)
+    })
   })
   describe("setBodyBackgroundToThemeBackgroundColor", () => {
     let _document: Document
@@ -228,11 +267,6 @@ describe("vscode", () => {
         },
         recordStats: true,
 
-        // TODO@jsjoeio address trustedTypesPolicy part
-        // might need to look up types
-        // and find a way to test the function
-        // maybe extract function into function
-        // and test manually
         trustedTypesPolicy: undefined,
         "vs/nls": {
           availableLanguages: {},
@@ -280,6 +314,11 @@ describe("vscode", () => {
 
       expect(loader.trustedTypesPolicy).not.toBe(undefined)
       expect(loader.trustedTypesPolicy.name).toBe("amdLoader")
+
+      // Check that we can actually create a script URL
+      // using the createScriptURL on the loader object
+      const scriptUrl = loader.trustedTypesPolicy.createScriptURL("http://localhost/foo.js")
+      expect(scriptUrl).toBe("http://localhost/foo.js")
     })
   })
   describe("_createScriptURL", () => {
diff --git a/test/yarn.lock b/test/yarn.lock
index 418eeeec..2fa48122 100644
--- a/test/yarn.lock
+++ b/test/yarn.lock
@@ -1757,6 +1757,13 @@ core-util-is@1.0.2, core-util-is@~1.0.0:
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
   integrity sha1-tf1UIgqivFq1eqtxQMlAdUUDwac=
 
+cross-fetch@^3.0.4:
+  version "3.1.4"
+  resolved "https://registry.yarnpkg.com/cross-fetch/-/cross-fetch-3.1.4.tgz#9723f3a3a247bf8b89039f3a380a9244e8fa2f39"
+  integrity sha512-1eAtFWdIubi6T4XPy6ei9iUFoKpUkIF971QLN8lIvvvwueI65+Nw5haMNKUwfJxabqlIIDODJKGrQ66gxC0PbQ==
+  dependencies:
+    node-fetch "2.6.1"
+
 cross-spawn@^6.0.0:
   version "6.0.5"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-6.0.5.tgz#4a5ec7c64dfae22c3a14124dbacdee846d80cbc4"
@@ -2800,6 +2807,14 @@ jest-environment-node@^26.6.2:
     jest-mock "^26.6.2"
     jest-util "^26.6.2"
 
+jest-fetch-mock@^3.0.3:
+  version "3.0.3"
+  resolved "https://registry.yarnpkg.com/jest-fetch-mock/-/jest-fetch-mock-3.0.3.tgz#31749c456ae27b8919d69824f1c2bd85fe0a1f3b"
+  integrity sha512-Ux1nWprtLrdrH4XwE7O7InRY6psIi3GOsqNESJgMJ+M5cv4A8Lh7SN9d2V2kKRZ8ebAfcd1LNyZguAOb6JiDqw==
+  dependencies:
+    cross-fetch "^3.0.4"
+    promise-polyfill "^8.1.3"
+
 jest-get-type@^26.3.0:
   version "26.3.0"
   resolved "https://registry.yarnpkg.com/jest-get-type/-/jest-get-type-26.3.0.tgz#e97dc3c3f53c2b406ca7afaed4493b1d099199e0"
@@ -3418,7 +3433,7 @@ node-addon-api@^3.0.2:
   resolved "https://registry.yarnpkg.com/node-addon-api/-/node-addon-api-3.2.1.tgz#81325e0a2117789c0128dab65e7e38f07ceba161"
   integrity sha512-mmcei9JghVNDYydghQmeDX8KoAm0FAiYyIcUt/N4nhyAipB17pllZQDOJD2fotxABnt4Mdz+dKTO7eftLg4d0A==
 
-node-fetch@^2.6.1:
+node-fetch@2.6.1, node-fetch@^2.6.1:
   version "2.6.1"
   resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.6.1.tgz#045bd323631f76ed2e2b55573394416b639a0052"
   integrity sha512-V4aYg89jEoVRxRb2fJdAg8FHvI7cEyYdVAh94HH0UIK8oJxUfkjlDQN9RbMx+bEjP7+ggMiFRprSti032Oipxw==
@@ -3762,6 +3777,11 @@ progress@^2.0.3:
   resolved "https://registry.yarnpkg.com/progress/-/progress-2.0.3.tgz#7e8cf8d8f5b8f239c1bc68beb4eb78567d572ef8"
   integrity sha512-7PiHtLll5LdnKIMw100I+8xJXR5gW2QwWYkT6iJva0bXitZKa/XMrSbdmg3r2Xnaidz9Qumd0VPaMrZlF9V9sA==
 
+promise-polyfill@^8.1.3:
+  version "8.2.0"
+  resolved "https://registry.yarnpkg.com/promise-polyfill/-/promise-polyfill-8.2.0.tgz#367394726da7561457aba2133c9ceefbd6267da0"
+  integrity sha512-k/TC0mIcPVF6yHhUvwAp7cvL6I2fFV7TzF1DuGPI8mBh4QQazf36xCKEHKTZKRysEoTQoQdKyP25J8MPJp7j5g==
+
 prompts@^2.0.1:
   version "2.4.0"
   resolved "https://registry.yarnpkg.com/prompts/-/prompts-2.4.0.tgz#4aa5de0723a231d1ee9121c40fdf663df73f61d7"