Return Type Improvements

Added some more established function return types, and looked into additional type checking capabilities for the `DataTransferItem` type.

BenjaminAster/Better-TypeScript#3

Had the Service Worker TypeScript-ready again, but realized that would be a bit too much to change all at once, and I didn't want to implement too many things to where it would break something unexpectedly again.

public/service-worker.js

@@ -3,7 +3,9 @@
 
 var self = /** @type { ServiceWorkerGlobalScope } */ (/** @type { unknown } */ (globalThis));
 
-const version = "Dovetail v1.6.0";
+const NAME = "Dovetail";
+const VERSION = "v1.6.1";
+const CACHE_NAME = /** @type { const } */ (`${NAME} ${VERSION}`);
 
 self.addEventListener("activate",event => {
  event.waitUntil(removeOutdatedVersions());
@@ -15,12 +17,14 @@ self.addEventListener("fetch",event => {
 
 /**
  * Clears out old versions of the app from Cache Storage.
+ * 
+ * @returns { Promise<void> }
 */
 async function removeOutdatedVersions(){
  const keys = await caches.keys();
 
  await Promise.all(keys.map(async key => {
- const isOutdatedVersion = key.startsWith("Dovetail ") && key !== version;
+ const isOutdatedVersion = key.startsWith(NAME) && key !== CACHE_NAME;
 
  if (isOutdatedVersion){
  await caches.delete(key);
@@ -36,6 +40,7 @@ async function removeOutdatedVersions(){
  * If it hasn't been cached yet, it will fetch the network for a response, cache a clone, then return the response.
  * 
  * @param { Request } request
+ * @returns { Promise<Response> }
 */
 async function matchRequest(request){
  let response = await caches.match(request);
@@ -52,8 +57,9 @@ async function matchRequest(request){
  * 
  * @param { Request } request
  * @param { Response } response
+ * @return { Promise<void> }
 */
 async function cacheRequest(request,response){
- const cache = await caches.open(version);
+ const cache = await caches.open(CACHE_NAME);
  await cache.put(request,response.clone());
 }

src/app.ts

@@ -1,5 +1,5 @@
 import "./compression-polyfill.js";
-import { read, write, parse, stringify, Name, Endian, Compression, BedrockLevel, Int32, NBTData, NBTDataOptions, CompressionFormat } from "nbtify";
+import { read, write, parse, stringify, Name, Endian, Compression, BedrockLevel, NBTData, NBTDataOptions, RootTag, Int32, CompressionFormat } from "nbtify";
 
 if (window.isSecureContext){
  await navigator.serviceWorker.register("./service-worker.js");
@@ -37,11 +37,12 @@ document.addEventListener("drop",async event => {
  event.preventDefault();
  if (event.dataTransfer === null) return;
 
- const items = [...event.dataTransfer.items].filter(item => item.kind === "file");
+ const items = [...event.dataTransfer.items]
+ .filter((item): item is Omit<DataTransferItem,"getAsFile"> & { getAsFile(): File; } => item.kind === "file");
  if (items.length === 0) return;
 
  const [item] = items;
- const file = item.getAsFile()!;
+ const file = item.getAsFile();
  await openFile(file);
 });
 
@@ -76,18 +77,10 @@ formatOpener.addEventListener("click",() => {
  formatDialog.showModal();
 });
 
-// const demo = await fetch("../NBTify/test/nbt/ridiculous.nbt")
-// .then(response => response.blob())
-// .then(blob => new File([blob],"ridiculous.nbt"));
-
-// await openFile(demo);
-
-// formatOpener.click();
-
 /**
  * Attempts to read an NBT file, then open it in the editor.
 */
-export async function openFile(file: File){
+export async function openFile(file: File): Promise<void> {
  saver.disabled = true;
  formatOpener.disabled = true;
  editor.disabled = true;
@@ -118,7 +111,7 @@ export interface FormatOptionsCollection extends HTMLFormControlsCollection {
 /**
  * Updates the Format Options dialog to match the NBT file's metadata.
 */
-export function openOptions({ name, endian, compression, bedrockLevel }: NBTData){
+export function openOptions({ name, endian, compression, bedrockLevel }: NBTData): NBTDataOptions {
  const elements = formatForm.elements as FormatOptionsCollection;
 
  if (name !== null){
@@ -134,23 +127,21 @@ export function openOptions({ name, endian, compression, bedrockLevel }: NBTData
  elements.compression.value = (compression === null) ? "none" : compression;
  elements.bedrockLevel.value = (bedrockLevel === null) ? "" : `${bedrockLevel}`;
 
- const options: NBTDataOptions = { name, endian, compression, bedrockLevel };
- return options;
+ return { name, endian, compression, bedrockLevel };
 }
 
 /**
  * Attempts to create an NBTData object from a File object.
 */
-export async function readFile(file: File){
+export async function readFile<T extends RootTag = any>(file: File): Promise<NBTData<T> | null> {
  const buffer = await file.arrayBuffer();
  try {
- const nbt = await read(buffer);
- return nbt;
- } catch (error: any){
- if ((error as Error).message.includes("unread bytes remaining")){
+ return await read(buffer);
+ } catch (error: unknown){
+ if (error instanceof Error && error.message.includes("unread bytes remaining")){
  const reattempt = confirm(`${error}\n\nEncountered extra data at the end of the file. Would you like to try opening it again without 'strict mode' enabled? The trailing data will be lost when re-saving your file again.`);
  if (!reattempt) return null;
- return read(buffer,{ strict: false });
+ return read<T>(buffer,{ strict: false });
  } else {
  alert(error);
  return null; 
@@ -161,22 +152,21 @@ export async function readFile(file: File){
 /**
  * Turns the values from the Format Options dialog into the NBT file's metadata.
 */
-export function saveOptions(){
+export function saveOptions(): NBTDataOptions {
  const elements = formatForm.elements as FormatOptionsCollection;
 
  const name: Name = (elements.disableName.checked) ? null : elements.name.value;
  const endian: Endian = elements.endian.value as Endian;
  const compression: Compression = (elements.compression.value === "none") ? null : elements.compression.value as CompressionFormat;
  const bedrockLevel: BedrockLevel = (elements.bedrockLevel.value === "") ? null : new Int32(parseInt(elements.bedrockLevel.value));
 
- const options: NBTDataOptions = { name, endian, compression, bedrockLevel };
- return options;
+ return { name, endian, compression, bedrockLevel };
 }
 
 /**
  * Shows the save file picker to the user.
 */
-export function saveFile(file: File){
+export function saveFile(file: File): void {
  const anchor = document.createElement("a");
  const blob = URL.createObjectURL(file);
 
@@ -190,7 +180,7 @@ export function saveFile(file: File){
 /**
  * Shows the file share menu to the user.
 */
-export async function shareFile(file: File){
+export async function shareFile(file: File): Promise<void> {
  try {
  await navigator.share({ files: [file] });
  } catch (error){
@@ -201,8 +191,7 @@ export async function shareFile(file: File){
 /**
  * Creates a File object from an NBTData object.
 */
-export async function writeFile(nbt: NBTData){
+export async function writeFile(nbt: NBTData): Promise<File> {
  const data = await write(nbt);
- const file = new File([data],name);
- return file;
+ return new File([data],name);
 }

src/compression-polyfill.ts

@@ -1,4 +1,7 @@
-export const usePolyfill: boolean = (() => {
+/**
+ * Specifies whether the Compression Streams API must be polyfilled to run in the current browser.
+*/
+const usePolyfill: boolean = (() => {
  try {
  new CompressionStream("deflate-raw");
  new DecompressionStream("deflate-raw");
@@ -9,14 +12,13 @@ export const usePolyfill: boolean = (() => {
 })();
 
 if (usePolyfill){
- const {
- makeCompressionStream,
- makeDecompressionStream
- } = await import("compression-streams-polyfill/ponyfill");
+ const { makeCompressionStream, makeDecompressionStream } = await import("compression-streams-polyfill/ponyfill");
 
  const CompressionStream = makeCompressionStream(TransformStream);
  const DecompressionStream = makeDecompressionStream(TransformStream);
 
  globalThis.CompressionStream = CompressionStream as typeof globalThis.CompressionStream;
  globalThis.DecompressionStream = DecompressionStream as typeof globalThis.DecompressionStream;
-}
+}
+
+export default usePolyfill;