diff --git a/src/testUtils.js b/src/testUtils.js
index 3fa8e37..75ac350 100644
--- a/src/testUtils.js
+++ b/src/testUtils.js
@@ -1,10 +1,22 @@
 import { expect } from '@playwright/test'
 
-// Return a valid URL of the test course or account - assertVariables.js will
-//  ensure these env vars exist and are normalised.
-export const TEST_URL = process.env.CANVAS_HOST + "/" + process.env.TEST_PATH
+/**
+ * Normalised test URL built from `CANVAS_HOST` and `TEST_PATH`.
+ * `src/setup/assertVariables.js` ensures these env vars exist and are normalised.
+ * @type {string}
+ */
+export const TEST_URL = process.env.CANVAS_HOST + '/' + process.env.TEST_PATH
 
 
+/**
+ * Perform an LTI login by requesting a session token and navigating the page
+ * to the returned session URL.
+ * @param {import('@playwright/test').APIRequestContext} request - Playwright request context
+ * @param {import('@playwright/test').Page} page - Playwright page to navigate
+ * @param {string} host - Canvas host (base URL)
+ * @param {string} token - OAuth bearer token
+ * @returns {Promise<void>}
+ */
 export const login = async (request, page, host, token) => {
   await Promise.resolve(
     await request.get(`${host}/login/session_token`, {
@@ -23,7 +35,19 @@ export const login = async (request, page, host, token) => {
   )
 }
 
-export const grantAccessIfNeeded = async(page, context, toolUrl) => {
+
+/**
+ * Visit `toolUrl` and complete the grant-access flow if the tool requests it.
+ * Navigates the page into the LTI tool, waits for loading to finish and
+ * resolves whether the tool requires an explicit grant. If required, the
+ * `grantAccess` helper is used to complete the flow.
+ *
+ * @param {import('@playwright/test').Page} page - Playwright page instance
+ * @param {import('@playwright/test').BrowserContext} context - Playwright browser context
+ * @param {string} toolUrl - URL of the LTI tool to visit
+ * @returns {Promise<void>}
+ */
+export const grantAccessIfNeeded = async (page, context, toolUrl) => {
   await page.goto(toolUrl)
   const ltiToolFrame = getLtiIFrame(page)
 
@@ -36,16 +60,24 @@ export const grantAccessIfNeeded = async(page, context, toolUrl) => {
 
   const needsGrantAccess = await Promise.race([
     ltiToolFrame.getByText('Please Grant Access').waitFor()
-      .then(() => { return true } ),
+      .then(() => { return true }),
     waitForNoSpinners(ltiToolFrame, 3000)
-      .then(() => { return false } )
+      .then(() => { return false })
   ])
 
-  if(needsGrantAccess){
+  if (needsGrantAccess) {
     await grantAccess(context, ltiToolFrame)
   }
 }
 
+/**
+ * Complete the grant access flow by clicking the authorise button in the
+ * popup page. Intended to be used by `grantAccessIfNeeded`.
+ *
+ * @param {import('@playwright/test').BrowserContext} context - Playwright browser context
+ * @param {import('@playwright/test').FrameLocator} frameLocator - Locator for the LTI frame
+ * @returns {Promise<void>}
+ */
 const grantAccess = async (context, frameLocator) => {
   const button = await frameLocator.getByRole('button')
   const [newPage] = await Promise.all([
@@ -53,32 +85,60 @@ const grantAccess = async (context, frameLocator) => {
     button.click()
   ])
 
-  const submit = await newPage.getByRole('button', {name: /Authori[sz]e/})
+  const submit = await newPage.getByRole('button', { name: /Authori[sz]e/ })
   await submit.click()
-  const close = await newPage.getByText('Close', {exact: true})
+  const close = await newPage.getByText('Close', { exact: true })
   await close.click()
 }
 
+
+/**
+ * Return the frame locator for the LTI launch iframe.
+ * @param {import('@playwright/test').Page} page - Playwright page
+ * @returns {import('@playwright/test').FrameLocator}
+ */
 export const getLtiIFrame = (page) => {
   return page.frameLocator('iframe[data-lti-launch="true"]')
 }
 
 let screenshotCount = 1
+/**
+ * Take a screenshot of the provided locator and save it into the test
+ * output directory. Files are numbered sequentially for the duration of the
+ * process.
+ *
+ * @param {import('@playwright/test').Locator} locator - Locator to screenshot
+ * @param {{ outputDir: string }} testInfo - Playwright `testInfo` object (only `outputDir` used)
+ * @returns {Promise<void>}
+ */
 export const screenshot = async (locator, testInfo) => {
-  await locator.screenshot({path: `${testInfo.outputDir}/${screenshotCount}.png`, fullPage: true})
+  await locator.screenshot({ path: `${testInfo.outputDir}/${screenshotCount}.png`, fullPage: true })
   screenshotCount++
 }
 
+/**
+ * Dismiss the beta warning banner if present on the current page.
+ * @param {import('@playwright/test').Page} page - Playwright page
+ * @returns {Promise<void>}
+ */
 export const dismissBetaBanner = async (page) => {
   if (page.url().includes('beta')) {
     const banner = page.getByRole('button', { name: 'Close warning' })
     if (await banner.isVisible()) {
-      await page.getByRole('button', {name: 'Close warning'}).click();
+      await page.getByRole('button', { name: 'Close warning' }).click()
     }
   }
 }
 
+/**
+ * Wait for any `.view-spinner` elements inside the supplied frame locator to
+ * disappear. Optionally provide an initial delay before checking.
+ *
+ * @param {import('@playwright/test').FrameLocator} frameLocator - Frame locator to query
+ * @param {number} [initialDelay=1000] - milliseconds to wait before starting checks
+ * @returns {Promise<void>}
+ */
 export const waitForNoSpinners = async (frameLocator, initialDelay = 1000) => {
-  await new Promise(r => setTimeout(r, initialDelay));
-  await expect(frameLocator.locator('.view-spinner')).toHaveCount(0, { timeout: 10000 });
+  await new Promise(r => setTimeout(r, initialDelay))
+  await expect(frameLocator.locator('.view-spinner')).toHaveCount(0, { timeout: 10000 })
 }
\ No newline at end of file