diff --git a/packages/builder/src/stores/builder/components.ts b/packages/builder/src/stores/builder/components.ts
index 9ad9a75f84..bce7fcb71d 100644
--- a/packages/builder/src/stores/builder/components.ts
+++ b/packages/builder/src/stores/builder/components.ts
@@ -33,7 +33,16 @@ import { Utils } from "@budibase/frontend-core"
 import { Component, FieldType, Screen, Table } from "@budibase/types"
 import { utils } from "@budibase/shared-core"
 
-interface ComponentDefinition {
+export interface ComponentState {
+  components: Record<string, ComponentDefinition>
+  customComponents: string[]
+  selectedComponentId?: string | null
+  componentToPaste?: Component | null
+  settingsCache: Record<string, ComponentSetting[]>
+  selectedScreenId?: string | null
+}
+
+export interface ComponentDefinition {
   component: string
   name: string
   friendlyName?: string
@@ -41,9 +50,11 @@ interface ComponentDefinition {
   settings?: ComponentSetting[]
   features?: Record<string, boolean>
   typeSupportPresets?: Record<string, any>
+  legalDirectChildren: string[]
+  illegalChildren: string[]
 }
 
-interface ComponentSetting {
+export interface ComponentSetting {
   key: string
   type: string
   section?: string
@@ -54,15 +65,6 @@ interface ComponentSetting {
   settings?: ComponentSetting[]
 }
 
-interface ComponentState {
-  components: Record<string, ComponentDefinition>
-  customComponents: string[]
-  selectedComponentId: string | null
-  componentToPaste?: Component | null
-  settingsCache: Record<string, ComponentSetting[]>
-  selectedScreenId?: string | null
-}
-
 export const INITIAL_COMPONENTS_STATE: ComponentState = {
   components: {},
   customComponents: [],
@@ -440,6 +442,11 @@ export class ComponentStore extends BudiStore<ComponentState> {
    * @returns
    */
   createInstance(componentName: string, presetProps: any, parent: any) {
+    const screen = get(selectedScreen)
+    if (!screen || !selectedScreen) {
+      throw "A valid screen must be selected"
+    }
+
     const definition = this.getDefinition(componentName)
     if (!definition) {
       return null
@@ -461,7 +468,7 @@ export class ComponentStore extends BudiStore<ComponentState> {
     // Standard post processing
     this.enrichEmptySettings(instance, {
       parent,
-      screen: get(selectedScreen),
+      screen,
       useDefaultValues: true,
     })
 
@@ -481,7 +488,7 @@ export class ComponentStore extends BudiStore<ComponentState> {
     // Add step name to form steps
     if (componentName.endsWith("/formstep")) {
       const parentForm = findClosestMatchingComponent(
-        get(selectedScreen).props,
+        screen.props,
         get(selectedComponent)._id,
         (component: Component) => component._component.endsWith("/form")
       )
@@ -841,6 +848,9 @@ export class ComponentStore extends BudiStore<ComponentState> {
     const state = get(this.store)
     const componentId = state.selectedComponentId
     const screen = get(selectedScreen)
+    if (!screen) {
+      throw "A valid screen must be selected"
+    }
     const parent = findComponentParent(screen.props, componentId)
     const index = parent?._children.findIndex(
       (x: Component) => x._id === componentId
@@ -890,6 +900,9 @@ export class ComponentStore extends BudiStore<ComponentState> {
     const component = get(selectedComponent)
     const componentId = component?._id
     const screen = get(selectedScreen)
+    if (!screen) {
+      throw "A valid screen must be selected"
+    }
     const parent = findComponentParent(screen.props, componentId)
     const index = parent?._children.findIndex(
       (x: Component) => x._id === componentId
diff --git a/packages/builder/src/stores/builder/index.js b/packages/builder/src/stores/builder/index.js
index 08d87bebf5..0d4682b551 100644
--- a/packages/builder/src/stores/builder/index.js
+++ b/packages/builder/src/stores/builder/index.js
@@ -3,7 +3,7 @@ import { appStore } from "./app.js"
 import { componentStore, selectedComponent } from "./components"
 import { navigationStore } from "./navigation.js"
 import { themeStore } from "./theme.js"
-import { screenStore, selectedScreen, sortedScreens } from "./screens.js"
+import { screenStore, selectedScreen, sortedScreens } from "./screens"
 import { builderStore } from "./builder.js"
 import { hoverStore } from "./hover.js"
 import { previewStore } from "./preview.js"
diff --git a/packages/builder/src/stores/builder/screens.js b/packages/builder/src/stores/builder/screens.ts
similarity index 77%
rename from packages/builder/src/stores/builder/screens.js
rename to packages/builder/src/stores/builder/screens.ts
index 8298a1469d..fd16cbfae8 100644
--- a/packages/builder/src/stores/builder/screens.js
+++ b/packages/builder/src/stores/builder/screens.ts
@@ -13,15 +13,32 @@ import {
 import { createHistoryStore } from "@/stores/builder/history"
 import { API } from "@/api"
 import { BudiStore } from "../BudiStore"
+import {
+  FetchAppPackageResponse,
+  DeleteScreenResponse,
+  Screen,
+  Component,
+} from "@budibase/types"
+import { ComponentDefinition } from "./components"
 
-export const INITIAL_SCREENS_STATE = {
-  screens: [],
-  selectedScreenId: null,
+interface ScreenState {
+  screens: Screen[]
+  selectedScreenId?: string
+  selected?: Screen
 }
 
-export class ScreenStore extends BudiStore {
+export const initialScreenState: ScreenState = {
+  screens: [],
+}
+
+// Review the nulls
+export class ScreenStore extends BudiStore<ScreenState> {
+  history: any
+  delete: any
+  save: any
+
   constructor() {
-    super(INITIAL_SCREENS_STATE)
+    super(initialScreenState)
 
     // Bind scope
     this.select = this.select.bind(this)
@@ -34,12 +51,15 @@ export class ScreenStore extends BudiStore {
     this.deleteScreen = this.deleteScreen.bind(this)
     this.syncScreenData = this.syncScreenData.bind(this)
     this.updateSetting = this.updateSetting.bind(this)
+    // TODO review this behaviour
     this.sequentialScreenPatch = this.sequentialScreenPatch.bind(this)
     this.removeCustomLayout = this.removeCustomLayout.bind(this)
 
     this.history = createHistoryStore({
-      getDoc: id => get(this.store).screens?.find(screen => screen._id === id),
+      getDoc: (id: string) =>
+        get(this.store).screens?.find(screen => screen._id === id),
       selectDoc: this.select,
+      beforeAction: () => {},
       afterAction: () => {
         // Ensure a valid component is selected
         if (!get(selectedComponent)) {
@@ -59,14 +79,14 @@ export class ScreenStore extends BudiStore {
    * Reset entire store back to base config
    */
   reset() {
-    this.store.set({ ...INITIAL_SCREENS_STATE })
+    this.store.set({ ...initialScreenState })
   }
 
   /**
    * Replace ALL store screens with application package screens
    * @param {object} pkg
    */
-  syncAppScreens(pkg) {
+  syncAppScreens(pkg: FetchAppPackageResponse) {
     this.update(state => ({
       ...state,
       screens: [...pkg.screens],
@@ -79,7 +99,7 @@ export class ScreenStore extends BudiStore {
    * @param {string} screenId
    * @returns
    */
-  select(screenId) {
+  select(screenId: string) {
     // Check this screen exists
     const state = get(this.store)
     const screen = state.screens.find(screen => screen._id === screenId)
@@ -107,14 +127,14 @@ export class ScreenStore extends BudiStore {
    * @throws Will throw an error containing the name of the component causing
    * the invalid screen state
    */
-  validate(screen) {
+  validate(screen: Screen) {
     // Recursive function to find any illegal children in component trees
     const findIllegalChild = (
-      component,
-      illegalChildren = [],
-      legalDirectChildren = []
-    ) => {
-      const type = component._component
+      component: Component,
+      illegalChildren: string[] = [],
+      legalDirectChildren: string[] = []
+    ): string | undefined => {
+      const type: string = component._component
 
       if (illegalChildren.includes(type)) {
         return type
@@ -137,7 +157,13 @@ export class ScreenStore extends BudiStore {
         illegalChildren = []
       }
 
-      const definition = componentStore.getDefinition(component._component)
+      const definition: ComponentDefinition | null =
+        componentStore.getDefinition(component._component)
+
+      if (definition == null) {
+        throw `Invalid defintion ${component._component}`
+      }
+
       // Reset whitelist for direct children
       legalDirectChildren = []
       if (definition?.legalDirectChildren?.length) {
@@ -172,7 +198,7 @@ export class ScreenStore extends BudiStore {
     const illegalChild = findIllegalChild(screen.props)
     if (illegalChild) {
       const def = componentStore.getDefinition(illegalChild)
-      throw `You can't place a ${def.name} here`
+      throw `You can't place a ${def?.name} here`
     }
   }
 
@@ -183,7 +209,7 @@ export class ScreenStore extends BudiStore {
    * @param {object} screen
    * @returns {object}
    */
-  async saveScreen(screen) {
+  async saveScreen(screen: Screen) {
     const appState = get(appStore)
 
     // Validate screen structure if the app supports it
@@ -230,7 +256,7 @@ export class ScreenStore extends BudiStore {
    * After saving a screen, sync plugins and routes to the appStore
    * @param {object} savedScreen
    */
-  async syncScreenData(savedScreen) {
+  async syncScreenData(savedScreen: Screen) {
     const appState = get(appStore)
     // If plugins changed we need to fetch the latest app metadata
     let usedPlugins = appState.usedPlugins
@@ -256,28 +282,51 @@ export class ScreenStore extends BudiStore {
    * This is slightly better than just a traditional "patch" endpoint and this
    * supports deeply mutating the current doc rather than just appending data.
    */
-  sequentialScreenPatch = Utils.sequential(async (patchFn, screenId) => {
-    const state = get(this.store)
-    const screen = state.screens.find(screen => screen._id === screenId)
-    if (!screen) {
-      return
-    }
-    let clone = cloneDeep(screen)
-    const result = patchFn(clone)
+  // sequentialScreenPatch = (
+  //   patchFn: (screen: Screen) => any,
+  //   screenId: string
+  // ) => {
+  //   return Utils.sequential(async () => {
+  //     const state = get(this.store)
+  //     const screen = state.screens.find(screen => screen._id === screenId)
+  //     if (!screen) {
+  //       return
+  //     }
+  //     let clone = cloneDeep(screen)
+  //     const result = patchFn(clone)
 
-    // An explicit false result means skip this change
-    if (result === false) {
-      return
+  //     // An explicit false result means skip this change
+  //     if (result === false) {
+  //       return
+  //     }
+  //     return this.save(clone)
+  //   })
+  // }
+
+  sequentialScreenPatch = Utils.sequential(
+    async (patchFn: (screen: Screen) => any, screenId: string) => {
+      const state = get(this.store)
+      const screen = state.screens.find(screen => screen._id === screenId)
+      if (!screen) {
+        return
+      }
+      let clone = cloneDeep(screen)
+      const result = patchFn(clone)
+
+      // An explicit false result means skip this change
+      if (result === false) {
+        return
+      }
+      return this.save(clone)
     }
-    return this.save(clone)
-  })
+  )
 
   /**
    * @param {function} patchFn
    * @param {string | null} screenId
    * @returns
    */
-  async patch(patchFn, screenId) {
+  async patch(patchFn: (screen: Screen) => any, screenId?: string | null) {
     // Default to the currently selected screen
     if (!screenId) {
       const state = get(this.store)
@@ -298,7 +347,7 @@ export class ScreenStore extends BudiStore {
    * @param {object} screen
    * @returns
    */
-  async replace(screenId, screen) {
+  async replace(screenId: string, screen: Screen) {
     if (!screenId) {
       return
     }
@@ -337,17 +386,25 @@ export class ScreenStore extends BudiStore {
    * @param {object | array} screens
    * @returns
    */
-  async deleteScreen(screens) {
+  async deleteScreen(screens: Screen[]) {
     const screensToDelete = Array.isArray(screens) ? screens : [screens]
     // Build array of promises to speed up bulk deletions
-    let promises = []
-    let deleteUrls = []
-    screensToDelete.forEach(screen => {
-      // Delete the screen
-      promises.push(API.deleteScreen(screen._id, screen._rev))
-      // Remove links to this screen
-      deleteUrls.push(screen.routing.route)
-    })
+    let promises: Promise<DeleteScreenResponse>[] = []
+    let deleteUrls: string[] = []
+
+    // In this instance _id will have been set
+    // Underline the expectation that _id and _rev will be set after filtering
+    screensToDelete
+      .filter(
+        (screen): screen is Screen & { _id: string; _rev: string } =>
+          !!screen._id || !!screen._rev
+      )
+      .forEach(screen => {
+        // Delete the screen
+        promises.push(API.deleteScreen(screen._id, screen._rev))
+        // Remove links to this screen
+        deleteUrls.push(screen.routing.route)
+      })
     await Promise.all(promises)
     await navigationStore.deleteLink(deleteUrls)
     const deletedIds = screensToDelete.map(screen => screen._id)
@@ -359,8 +416,11 @@ export class ScreenStore extends BudiStore {
       })
 
       // Deselect the current screen if it was deleted
-      if (deletedIds.includes(state.selectedScreenId)) {
-        state.selectedScreenId = null
+      if (
+        state.selectedScreenId &&
+        deletedIds.includes(state.selectedScreenId)
+      ) {
+        delete state.selectedScreenId
         componentStore.update(state => ({
           ...state,
           selectedComponentId: null,
@@ -389,13 +449,13 @@ export class ScreenStore extends BudiStore {
    * @param {any} value
    * @returns
    */
-  async updateSetting(screen, name, value) {
+  async updateSetting(screen: Screen, name: string, value: any) {
     if (!screen || !name) {
       return
     }
 
     // Apply setting update
-    const patchFn = screen => {
+    const patchFn = (screen: Screen) => {
       if (!screen) {
         return false
       }
@@ -422,7 +482,7 @@ export class ScreenStore extends BudiStore {
       )
     })
     if (otherHomeScreens.length && updatedScreen.routing.homeScreen) {
-      const patchFn = screen => {
+      const patchFn = (screen: Screen) => {
         screen.routing.homeScreen = false
       }
       for (let otherHomeScreen of otherHomeScreens) {
@@ -432,11 +492,11 @@ export class ScreenStore extends BudiStore {
   }
 
   // Move to layouts store
-  async removeCustomLayout(screen) {
+  async removeCustomLayout(screen: Screen) {
     // Pull relevant settings from old layout, if required
     const layout = get(layoutStore).layouts.find(x => x._id === screen.layoutId)
-    const patchFn = screen => {
-      screen.layoutId = null
+    const patchFn = (screen: Screen) => {
+      delete screen.layoutId
       screen.showNavigation = layout?.props.navigation !== "None"
       screen.width = layout?.props.width || "Large"
     }
@@ -448,9 +508,12 @@ export class ScreenStore extends BudiStore {
    * and up-to-date. Ensures stability after a product update.
    * @param {object} screen
    */
-  async enrichEmptySettings(screen) {
+  async enrichEmptySettings(screen: Screen) {
     // Flatten the recursive component tree
-    const components = findAllMatchingComponents(screen.props, x => x)
+    const components = findAllMatchingComponents(
+      screen.props,
+      (x: Component) => x
+    )
 
     // Iterate over all components and run checks
     components.forEach(component => {
diff --git a/packages/builder/src/stores/builder/tests/screens.test.js b/packages/builder/src/stores/builder/tests/screens.test.js
index 430605b77a..87eb03ea04 100644
--- a/packages/builder/src/stores/builder/tests/screens.test.js
+++ b/packages/builder/src/stores/builder/tests/screens.test.js
@@ -3,7 +3,7 @@ import { get, writable } from "svelte/store"
 import { API } from "@/api"
 import { Constants } from "@budibase/frontend-core"
 import { componentStore, appStore } from "@/stores/builder"
-import { INITIAL_SCREENS_STATE, ScreenStore } from "@/stores/builder/screens"
+import { initialScreenState, ScreenStore } from "@/stores/builder/screens"
 import {
   getScreenFixture,
   getComponentFixture,
@@ -73,7 +73,7 @@ describe("Screens store", () => {
     vi.clearAllMocks()
 
     const screenStore = new ScreenStore()
-    ctx.test = {
+    ctx.bb = {
       get store() {
         return get(screenStore)
       },
@@ -81,74 +81,76 @@ describe("Screens store", () => {
     }
   })
 
-  it("Create base screen store with defaults", ctx => {
-    expect(ctx.test.store).toStrictEqual(INITIAL_SCREENS_STATE)
+  it("Create base screen store with defaults", ({ bb }) => {
+    expect(bb.store).toStrictEqual(initialScreenState)
   })
 
-  it("Syncs all screens from the app package", ctx => {
-    expect(ctx.test.store.screens.length).toBe(0)
+  it("Syncs all screens from the app package", ({ bb }) => {
+    expect(bb.store.screens.length).toBe(0)
 
     const screens = Array(2)
       .fill()
       .map(() => getScreenFixture().json())
 
-    ctx.test.screenStore.syncAppScreens({ screens })
+    bb.screenStore.syncAppScreens({ screens })
 
-    expect(ctx.test.store.screens).toStrictEqual(screens)
+    expect(bb.store.screens).toStrictEqual(screens)
   })
 
-  it("Reset the screen store back to the default state", ctx => {
-    expect(ctx.test.store.screens.length).toBe(0)
+  it("Reset the screen store back to the default state", ({ bb }) => {
+    expect(bb.store.screens.length).toBe(0)
 
     const screens = Array(2)
       .fill()
       .map(() => getScreenFixture().json())
 
-    ctx.test.screenStore.syncAppScreens({ screens })
-    expect(ctx.test.store.screens).toStrictEqual(screens)
+    bb.screenStore.syncAppScreens({ screens })
+    expect(bb.store.screens).toStrictEqual(screens)
 
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       selectedScreenId: screens[0]._id,
     }))
 
-    ctx.test.screenStore.reset()
+    bb.screenStore.reset()
 
-    expect(ctx.test.store).toStrictEqual(INITIAL_SCREENS_STATE)
+    expect(bb.store).toStrictEqual(initialScreenState)
   })
 
-  it("Marks a valid screen as selected", ctx => {
+  it("Marks a valid screen as selected", ({ bb }) => {
     const screens = Array(2)
       .fill()
       .map(() => getScreenFixture().json())
 
-    ctx.test.screenStore.syncAppScreens({ screens })
-    expect(ctx.test.store.screens.length).toBe(2)
+    bb.screenStore.syncAppScreens({ screens })
+    expect(bb.store.screens.length).toBe(2)
 
-    ctx.test.screenStore.select(screens[0]._id)
+    bb.screenStore.select(screens[0]._id)
 
-    expect(ctx.test.store.selectedScreenId).toEqual(screens[0]._id)
+    expect(bb.store.selectedScreenId).toEqual(screens[0]._id)
   })
 
-  it("Skip selecting a screen if it is not present", ctx => {
+  it("Skip selecting a screen if it is not present", ({ bb }) => {
     const screens = Array(2)
       .fill()
       .map(() => getScreenFixture().json())
 
-    ctx.test.screenStore.syncAppScreens({ screens })
-    expect(ctx.test.store.screens.length).toBe(2)
+    bb.screenStore.syncAppScreens({ screens })
+    expect(bb.store.screens.length).toBe(2)
 
-    ctx.test.screenStore.select("screen_abc")
+    bb.screenStore.select("screen_abc")
 
-    expect(ctx.test.store.selectedScreenId).toBeNull()
+    expect(bb.store.selectedScreenId).toBeUndefined()
   })
 
-  it("Approve a valid empty screen config", ctx => {
+  it("Approve a valid empty screen config", ({ bb }) => {
     const coreScreen = getScreenFixture()
-    ctx.test.screenStore.validate(coreScreen.json())
+    bb.screenStore.validate(coreScreen.json())
   })
 
-  it("Approve a valid screen config with one component and no illegal children", ctx => {
+  it("Approve a valid screen config with one component and no illegal children", ({
+    bb,
+  }) => {
     const coreScreen = getScreenFixture()
     const formBlock = getComponentFixture(`${COMP_PREFIX}/formblock`)
 
@@ -157,12 +159,12 @@ describe("Screens store", () => {
     const defSpy = vi.spyOn(componentStore, "getDefinition")
     defSpy.mockReturnValueOnce(COMPONENT_DEFINITIONS.formblock)
 
-    ctx.test.screenStore.validate(coreScreen.json())
+    bb.screenStore.validate(coreScreen.json())
 
     expect(defSpy).toHaveBeenCalled()
   })
 
-  it("Reject an attempt to nest invalid components", ctx => {
+  it("Reject an attempt to nest invalid components", ({ bb }) => {
     const coreScreen = getScreenFixture()
 
     const formOne = getComponentFixture(`${COMP_PREFIX}/form`)
@@ -178,14 +180,14 @@ describe("Screens store", () => {
         return defMap[comp]
       })
 
-    expect(() => ctx.test.screenStore.validate(coreScreen.json())).toThrowError(
+    expect(() => bb.screenStore.validate(coreScreen.json())).toThrowError(
       `You can't place a ${COMPONENT_DEFINITIONS.form.name} here`
     )
 
     expect(defSpy).toHaveBeenCalled()
   })
 
-  it("Reject an attempt to deeply nest invalid components", ctx => {
+  it("Reject an attempt to deeply nest invalid components", ({ bb }) => {
     const coreScreen = getScreenFixture()
 
     const formOne = getComponentFixture(`${COMP_PREFIX}/form`)
@@ -210,14 +212,16 @@ describe("Screens store", () => {
         return defMap[comp]
       })
 
-    expect(() => ctx.test.screenStore.validate(coreScreen.json())).toThrowError(
+    expect(() => bb.screenStore.validate(coreScreen.json())).toThrowError(
       `You can't place a ${COMPONENT_DEFINITIONS.form.name} here`
     )
 
     expect(defSpy).toHaveBeenCalled()
   })
 
-  it("Save a brand new screen and add it to the store. No validation", async ctx => {
+  it("Save a brand new screen and add it to the store. No validation", async ({
+    bb,
+  }) => {
     const coreScreen = getScreenFixture()
     const formOne = getComponentFixture(`${COMP_PREFIX}/form`)
 
@@ -225,7 +229,7 @@ describe("Screens store", () => {
 
     appStore.set({ features: { componentValidation: false } })
 
-    expect(ctx.test.store.screens.length).toBe(0)
+    expect(bb.store.screens.length).toBe(0)
 
     const newDocId = getScreenDocId()
     const newDoc = { ...coreScreen.json(), _id: newDocId }
@@ -235,15 +239,15 @@ describe("Screens store", () => {
     vi.spyOn(API, "fetchAppRoutes").mockResolvedValue({
       routes: [],
     })
-    await ctx.test.screenStore.save(coreScreen.json())
+    await bb.screenStore.save(coreScreen.json())
 
     expect(saveSpy).toHaveBeenCalled()
 
-    expect(ctx.test.store.screens.length).toBe(1)
+    expect(bb.store.screens.length).toBe(1)
 
-    expect(ctx.test.store.screens[0]).toStrictEqual(newDoc)
+    expect(bb.store.screens[0]).toStrictEqual(newDoc)
 
-    expect(ctx.test.store.selectedScreenId).toBe(newDocId)
+    expect(bb.store.selectedScreenId).toBe(newDocId)
 
     // The new screen should be selected
     expect(get(componentStore).selectedComponentId).toBe(
@@ -251,7 +255,7 @@ describe("Screens store", () => {
     )
   })
 
-  it("Sync an updated screen to the screen store on save", async ctx => {
+  it("Sync an updated screen to the screen store on save", async ({ bb }) => {
     const existingScreens = Array(4)
       .fill()
       .map(() => {
@@ -261,7 +265,7 @@ describe("Screens store", () => {
         return screenDoc
       })
 
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       screens: existingScreens.map(screen => screen.json()),
     }))
@@ -279,16 +283,18 @@ describe("Screens store", () => {
     })
 
     // Saved the existing screen having modified it.
-    await ctx.test.screenStore.save(existingScreens[2].json())
+    await bb.screenStore.save(existingScreens[2].json())
 
     expect(routeSpy).toHaveBeenCalled()
     expect(saveSpy).toHaveBeenCalled()
 
     // On save, the screen is spliced back into the store with the saved content
-    expect(ctx.test.store.screens[2]).toStrictEqual(existingScreens[2].json())
+    expect(bb.store.screens[2]).toStrictEqual(existingScreens[2].json())
   })
 
-  it("Sync API data to relevant stores on save. Updated plugins", async ctx => {
+  it("Sync API data to relevant stores on save. Updated plugins", async ({
+    bb,
+  }) => {
     const coreScreen = getScreenFixture()
 
     const newDocId = getScreenDocId()
@@ -318,7 +324,7 @@ describe("Screens store", () => {
       routes: [],
     })
 
-    await ctx.test.screenStore.syncScreenData(newDoc)
+    await bb.screenStore.syncScreenData(newDoc)
 
     expect(routeSpy).toHaveBeenCalled()
     expect(appPackageSpy).toHaveBeenCalled()
@@ -326,7 +332,9 @@ describe("Screens store", () => {
     expect(get(appStore).usedPlugins).toStrictEqual(plugins)
   })
 
-  it("Sync API updates to relevant stores on save. Plugins unchanged", async ctx => {
+  it("Sync API updates to relevant stores on save. Plugins unchanged", async ({
+    bb,
+  }) => {
     const coreScreen = getScreenFixture()
 
     const newDocId = getScreenDocId()
@@ -343,7 +351,7 @@ describe("Screens store", () => {
       routes: [],
     })
 
-    await ctx.test.screenStore.syncScreenData(newDoc)
+    await bb.screenStore.syncScreenData(newDoc)
 
     expect(routeSpy).toHaveBeenCalled()
     expect(appPackageSpy).not.toHaveBeenCalled()
@@ -352,46 +360,48 @@ describe("Screens store", () => {
     expect(get(appStore).usedPlugins).toStrictEqual([plugin])
   })
 
-  it("Proceed to patch if appropriate config are supplied", async ctx => {
-    vi.spyOn(ctx.test.screenStore, "sequentialScreenPatch").mockImplementation(
-      () => {
-        return false
-      }
-    )
+  it("Proceed to patch if appropriate config are supplied", async ({ bb }) => {
+    vi.spyOn(bb.screenStore, "sequentialScreenPatch").mockImplementation(() => {
+      return false
+    })
     const noop = () => {}
 
-    await ctx.test.screenStore.patch(noop, "test")
-    expect(ctx.test.screenStore.sequentialScreenPatch).toHaveBeenCalledWith(
+    await bb.screenStore.patch(noop, "test")
+    expect(bb.screenStore.sequentialScreenPatch).toHaveBeenCalledWith(
       noop,
       "test"
     )
   })
 
-  it("Return from the patch if all valid config are not present", async ctx => {
-    vi.spyOn(ctx.test.screenStore, "sequentialScreenPatch")
-    await ctx.test.screenStore.patch()
-    expect(ctx.test.screenStore.sequentialScreenPatch).not.toBeCalled()
+  it("Return from the patch if all valid config are not present", async ({
+    bb,
+  }) => {
+    vi.spyOn(bb.screenStore, "sequentialScreenPatch")
+    await bb.screenStore.patch()
+    expect(bb.screenStore.sequentialScreenPatch).not.toBeCalled()
   })
 
-  it("Acquire the currently selected screen on patch, if not specified", async ctx => {
-    vi.spyOn(ctx.test.screenStore, "sequentialScreenPatch")
-    await ctx.test.screenStore.patch()
+  it("Acquire the currently selected screen on patch, if not specified", async ({
+    bb,
+  }) => {
+    vi.spyOn(bb.screenStore, "sequentialScreenPatch")
+    await bb.screenStore.patch()
 
     const noop = () => {}
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       selectedScreenId: "screen_123",
     }))
 
-    await ctx.test.screenStore.patch(noop)
-    expect(ctx.test.screenStore.sequentialScreenPatch).toHaveBeenCalledWith(
+    await bb.screenStore.patch(noop)
+    expect(bb.screenStore.sequentialScreenPatch).toHaveBeenCalledWith(
       noop,
       "screen_123"
     )
   })
 
   // Used by the websocket
-  it("Ignore a call to replace if no screenId is provided", ctx => {
+  it("Ignore a call to replace if no screenId is provided", ({ bb }) => {
     const existingScreens = Array(4)
       .fill()
       .map(() => {
@@ -400,14 +410,16 @@ describe("Screens store", () => {
         screenDoc._json._id = existingDocId
         return screenDoc.json()
       })
-    ctx.test.screenStore.syncAppScreens({ screens: existingScreens })
+    bb.screenStore.syncAppScreens({ screens: existingScreens })
 
-    ctx.test.screenStore.replace()
+    bb.screenStore.replace()
 
-    expect(ctx.test.store.screens).toStrictEqual(existingScreens)
+    expect(bb.store.screens).toStrictEqual(existingScreens)
   })
 
-  it("Remove a screen from the store if a single screenId is supplied", ctx => {
+  it("Remove a screen from the store if a single screenId is supplied", ({
+    bb,
+  }) => {
     const existingScreens = Array(4)
       .fill()
       .map(() => {
@@ -416,17 +428,17 @@ describe("Screens store", () => {
         screenDoc._json._id = existingDocId
         return screenDoc.json()
       })
-    ctx.test.screenStore.syncAppScreens({ screens: existingScreens })
+    bb.screenStore.syncAppScreens({ screens: existingScreens })
 
-    ctx.test.screenStore.replace(existingScreens[1]._id)
+    bb.screenStore.replace(existingScreens[1]._id)
 
     const filtered = existingScreens.filter(
       screen => screen._id != existingScreens[1]._id
     )
-    expect(ctx.test.store.screens).toStrictEqual(filtered)
+    expect(bb.store.screens).toStrictEqual(filtered)
   })
 
-  it("Replace an existing screen with a new version of itself", ctx => {
+  it("Replace an existing screen with a new version of itself", ({ bb }) => {
     const existingScreens = Array(4)
       .fill()
       .map(() => {
@@ -436,7 +448,7 @@ describe("Screens store", () => {
         return screenDoc
       })
 
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       screens: existingScreens.map(screen => screen.json()),
     }))
@@ -444,15 +456,14 @@ describe("Screens store", () => {
     const formBlock = getComponentFixture(`${COMP_PREFIX}/formblock`)
     existingScreens[2].addChild(formBlock)
 
-    ctx.test.screenStore.replace(
-      existingScreens[2]._id,
-      existingScreens[2].json()
-    )
+    bb.screenStore.replace(existingScreens[2]._id, existingScreens[2].json())
 
-    expect(ctx.test.store.screens.length).toBe(4)
+    expect(bb.store.screens.length).toBe(4)
   })
 
-  it("Add a screen when attempting to replace one not present in the store", ctx => {
+  it("Add a screen when attempting to replace one not present in the store", ({
+    bb,
+  }) => {
     const existingScreens = Array(4)
       .fill()
       .map(() => {
@@ -462,7 +473,7 @@ describe("Screens store", () => {
         return screenDoc
       })
 
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       screens: existingScreens.map(screen => screen.json()),
     }))
@@ -470,13 +481,13 @@ describe("Screens store", () => {
     const newScreenDoc = getScreenFixture()
     newScreenDoc._json._id = getScreenDocId()
 
-    ctx.test.screenStore.replace(newScreenDoc._json._id, newScreenDoc.json())
+    bb.screenStore.replace(newScreenDoc._json._id, newScreenDoc.json())
 
-    expect(ctx.test.store.screens.length).toBe(5)
-    expect(ctx.test.store.screens[4]).toStrictEqual(newScreenDoc.json())
+    expect(bb.store.screens.length).toBe(5)
+    expect(bb.store.screens[4]).toStrictEqual(newScreenDoc.json())
   })
 
-  it("Delete a single screen and remove it from the store", async ctx => {
+  it("Delete a single screen and remove it from the store", async ({ bb }) => {
     const existingScreens = Array(3)
       .fill()
       .map(() => {
@@ -486,14 +497,14 @@ describe("Screens store", () => {
         return screenDoc
       })
 
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       screens: existingScreens.map(screen => screen.json()),
     }))
 
     const deleteSpy = vi.spyOn(API, "deleteScreen")
 
-    await ctx.test.screenStore.delete(existingScreens[2].json())
+    await bb.screenStore.delete(existingScreens[2].json())
 
     vi.spyOn(API, "fetchAppRoutes").mockResolvedValue({
       routes: [],
@@ -501,13 +512,15 @@ describe("Screens store", () => {
 
     expect(deleteSpy).toBeCalled()
 
-    expect(ctx.test.store.screens.length).toBe(2)
+    expect(bb.store.screens.length).toBe(2)
 
     // Just confirm that the routes at are being initialised
     expect(get(appStore).routes).toEqual([])
   })
 
-  it("Upon delete, reset selected screen and component ids if the screen was selected", async ctx => {
+  it("Upon delete, reset selected screen and component ids if the screen was selected", async ({
+    bb,
+  }) => {
     const existingScreens = Array(3)
       .fill()
       .map(() => {
@@ -517,7 +530,7 @@ describe("Screens store", () => {
         return screenDoc
       })
 
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       screens: existingScreens.map(screen => screen.json()),
       selectedScreenId: existingScreens[2]._json._id,
@@ -528,14 +541,16 @@ describe("Screens store", () => {
       selectedComponentId: existingScreens[2]._json._id,
     }))
 
-    await ctx.test.screenStore.delete(existingScreens[2].json())
+    await bb.screenStore.delete(existingScreens[2].json())
 
-    expect(ctx.test.store.screens.length).toBe(2)
+    expect(bb.store.screens.length).toBe(2)
     expect(get(componentStore).selectedComponentId).toBeNull()
-    expect(ctx.test.store.selectedScreenId).toBeNull()
+    expect(bb.store.selectedScreenId).toBeUndefined()
   })
 
-  it("Delete multiple is not supported and should leave the store unchanged", async ctx => {
+  it("Delete multiple is not supported and should leave the store unchanged", async ({
+    bb,
+  }) => {
     const existingScreens = Array(3)
       .fill()
       .map(() => {
@@ -547,7 +562,7 @@ describe("Screens store", () => {
 
     const storeScreens = existingScreens.map(screen => screen.json())
 
-    ctx.test.screenStore.update(state => ({
+    bb.screenStore.update(state => ({
       ...state,
       screens: existingScreens.map(screen => screen.json()),
     }))
@@ -556,42 +571,40 @@ describe("Screens store", () => {
 
     const deleteSpy = vi.spyOn(API, "deleteScreen")
 
-    await ctx.test.screenStore.delete(targets)
+    await bb.screenStore.delete(targets)
 
     expect(deleteSpy).not.toHaveBeenCalled()
-    expect(ctx.test.store.screens.length).toBe(3)
-    expect(ctx.test.store.screens).toStrictEqual(storeScreens)
+    expect(bb.store.screens.length).toBe(3)
+    expect(bb.store.screens).toStrictEqual(storeScreens)
   })
 
-  it("Update a screen setting", async ctx => {
+  it("Update a screen setting", async ({ bb }) => {
     const screenDoc = getScreenFixture()
     const existingDocId = getScreenDocId()
     screenDoc._json._id = existingDocId
 
-    await ctx.test.screenStore.update(state => ({
+    await bb.screenStore.update(state => ({
       ...state,
       screens: [screenDoc.json()],
     }))
 
     const patchedDoc = screenDoc.json()
     const patchSpy = vi
-      .spyOn(ctx.test.screenStore, "patch")
+      .spyOn(bb.screenStore, "patch")
       .mockImplementation(async patchFn => {
         patchFn(patchedDoc)
         return
       })
 
-    await ctx.test.screenStore.updateSetting(
-      patchedDoc,
-      "showNavigation",
-      false
-    )
+    await bb.screenStore.updateSetting(patchedDoc, "showNavigation", false)
 
     expect(patchSpy).toBeCalled()
     expect(patchedDoc.showNavigation).toBe(false)
   })
 
-  it("Ensure only one homescreen per role after updating setting. All screens same role", async ctx => {
+  it("Ensure only one homescreen per role after updating setting. All screens same role", async ({
+    bb,
+  }) => {
     const existingScreens = Array(3)
       .fill()
       .map(() => {
@@ -611,23 +624,21 @@ describe("Screens store", () => {
     // Set the 2nd screen as the home screen
     storeScreens[1].routing.homeScreen = true
 
-    await ctx.test.screenStore.update(state => ({
+    await bb.screenStore.update(state => ({
       ...state,
       screens: storeScreens,
     }))
 
     const patchSpy = vi
-      .spyOn(ctx.test.screenStore, "patch")
+      .spyOn(bb.screenStore, "patch")
       .mockImplementation(async (patchFn, screenId) => {
-        const target = ctx.test.store.screens.find(
-          screen => screen._id === screenId
-        )
+        const target = bb.store.screens.find(screen => screen._id === screenId)
         patchFn(target)
 
-        await ctx.test.screenStore.replace(screenId, target)
+        await bb.screenStore.replace(screenId, target)
       })
 
-    await ctx.test.screenStore.updateSetting(
+    await bb.screenStore.updateSetting(
       storeScreens[0],
       "routing.homeScreen",
       true
@@ -637,13 +648,15 @@ describe("Screens store", () => {
     expect(patchSpy).toBeCalledTimes(2)
 
     // The new homescreen for BASIC
-    expect(ctx.test.store.screens[0].routing.homeScreen).toBe(true)
+    expect(bb.store.screens[0].routing.homeScreen).toBe(true)
 
     // The previous home screen for the BASIC role is now unset
-    expect(ctx.test.store.screens[1].routing.homeScreen).toBe(false)
+    expect(bb.store.screens[1].routing.homeScreen).toBe(false)
   })
 
-  it("Ensure only one homescreen per role when updating screen setting. Multiple screen roles", async ctx => {
+  it("Ensure only one homescreen per role when updating screen setting. Multiple screen roles", async ({
+    bb,
+  }) => {
     const expectedRoles = [
       Constants.Roles.BASIC,
       Constants.Roles.POWER,
@@ -675,30 +688,24 @@ describe("Screens store", () => {
     sorted[9].routing.homeScreen = true
 
     // Set screens state
-    await ctx.test.screenStore.update(state => ({
+    await bb.screenStore.update(state => ({
       ...state,
       screens: sorted,
     }))
 
     const patchSpy = vi
-      .spyOn(ctx.test.screenStore, "patch")
+      .spyOn(bb.screenStore, "patch")
       .mockImplementation(async (patchFn, screenId) => {
-        const target = ctx.test.store.screens.find(
-          screen => screen._id === screenId
-        )
+        const target = bb.store.screens.find(screen => screen._id === screenId)
         patchFn(target)
 
-        await ctx.test.screenStore.replace(screenId, target)
+        await bb.screenStore.replace(screenId, target)
       })
 
     // ADMIN homeScreen updated from 0 to 2
-    await ctx.test.screenStore.updateSetting(
-      sorted[2],
-      "routing.homeScreen",
-      true
-    )
+    await bb.screenStore.updateSetting(sorted[2], "routing.homeScreen", true)
 
-    const results = ctx.test.store.screens.reduce((acc, screen) => {
+    const results = bb.store.screens.reduce((acc, screen) => {
       if (screen.routing.homeScreen) {
         acc[screen.routing.roleId] = acc[screen.routing.roleId] || []
         acc[screen.routing.roleId].push(screen)
@@ -706,7 +713,7 @@ describe("Screens store", () => {
       return acc
     }, {})
 
-    const screens = ctx.test.store.screens
+    const screens = bb.store.screens
     // Should still only be one of each homescreen
     expect(results[Constants.Roles.ADMIN].length).toBe(1)
     expect(screens[2].routing.homeScreen).toBe(true)
@@ -724,74 +731,80 @@ describe("Screens store", () => {
     expect(patchSpy).toBeCalledTimes(2)
   })
 
-  it("Sequential patch check. Exit if the screenId is not valid.", async ctx => {
+  it("Sequential patch check. Exit if the screenId is not valid.", async ({
+    bb,
+  }) => {
     const screenDoc = getScreenFixture()
     const existingDocId = getScreenDocId()
     screenDoc._json._id = existingDocId
 
     const original = screenDoc.json()
 
-    await ctx.test.screenStore.update(state => ({
+    await bb.screenStore.update(state => ({
       ...state,
       screens: [original],
     }))
 
     const saveSpy = vi
-      .spyOn(ctx.test.screenStore, "save")
+      .spyOn(bb.screenStore, "save")
       .mockImplementation(async () => {
         return
       })
 
     // A screen with this Id does not exist
-    await ctx.test.screenStore.sequentialScreenPatch(() => {}, "123")
+    await bb.screenStore.sequentialScreenPatch(() => {}, "123")
     expect(saveSpy).not.toBeCalled()
   })
 
-  it("Sequential patch check. Exit if the patchFn result is false", async ctx => {
+  it("Sequential patch check. Exit if the patchFn result is false", async ({
+    bb,
+  }) => {
     const screenDoc = getScreenFixture()
     const existingDocId = getScreenDocId()
     screenDoc._json._id = existingDocId
 
     const original = screenDoc.json()
     // Set screens state
-    await ctx.test.screenStore.update(state => ({
+    await bb.screenStore.update(state => ({
       ...state,
       screens: [original],
     }))
 
     const saveSpy = vi
-      .spyOn(ctx.test.screenStore, "save")
+      .spyOn(bb.screenStore, "save")
       .mockImplementation(async () => {
         return
       })
 
     // Returning false from the patch will abort the save
-    await ctx.test.screenStore.sequentialScreenPatch(() => {
+    await bb.screenStore.sequentialScreenPatch(() => {
       return false
     }, "123")
 
     expect(saveSpy).not.toBeCalled()
   })
 
-  it("Sequential patch check. Patch applied and save requested", async ctx => {
+  it("Sequential patch check. Patch applied and save requested", async ({
+    bb,
+  }) => {
     const screenDoc = getScreenFixture()
     const existingDocId = getScreenDocId()
     screenDoc._json._id = existingDocId
 
     const original = screenDoc.json()
 
-    await ctx.test.screenStore.update(state => ({
+    await bb.screenStore.update(state => ({
       ...state,
       screens: [original],
     }))
 
     const saveSpy = vi
-      .spyOn(ctx.test.screenStore, "save")
+      .spyOn(bb.screenStore, "save")
       .mockImplementation(async () => {
         return
       })
 
-    await ctx.test.screenStore.sequentialScreenPatch(screen => {
+    await bb.screenStore.sequentialScreenPatch(screen => {
       screen.name = "updated"
     }, existingDocId)
 
diff --git a/packages/frontend-core/src/utils/utils.js b/packages/frontend-core/src/utils/utils.js
index c424aea5b2..eeff561215 100644
--- a/packages/frontend-core/src/utils/utils.js
+++ b/packages/frontend-core/src/utils/utils.js
@@ -8,7 +8,7 @@ export const sleep = ms => new Promise(resolve => setTimeout(resolve, ms))
  * Utility to wrap an async function and ensure all invocations happen
  * sequentially.
  * @param fn the async function to run
- * @return {Promise} a sequential version of the function
+ * @return {Function} a sequential version of the function
  */
 export const sequential = fn => {
   let queue = []