Typescriptify libsquoosh's codecs and emscripten-utils

libsquoosh/src/codecs.ts

@@ -1,5 +1,28 @@
 import { promises as fsp } from 'fs';
-import { instantiateEmscriptenWasm, pathify } from './emscripten-utils.js';
+import { instantiateEmscriptenWasm, pathify } from './emscripten-utils';
+
+interface RotateModuleInstance {
+  exports: {
+    memory: WebAssembly.Memory;
+    rotate(width: number, height: number, rotate: number): void;
+  };
+}
+
+interface ResizeWithAspectParams {
+  input_width: number;
+  input_height: number;
+  target_width: number;
+  target_height: number;
+}
+
+declare global {
+  // Needed for being able to use ImageData as type in codec types
+  type ImageData = typeof import('./image_data');
+  // Needed for being able to assign to `globalThis.ImageData`
+  var ImageData: ImageData['constructor'];
+}
+
+import type { QuantizerModule } from '../../codecs/imagequant/imagequant';
 
 // MozJPEG
 import mozEnc from '../../codecs/mozjpeg/enc/mozjpeg_node_enc.js';
@@ -51,16 +74,22 @@ const resizePromise = resize.default(fsp.readFile(pathify(resizeWasm)));
 // rotate
 import rotateWasm from 'asset-url:../../codecs/rotate/rotate.wasm';
 
+// TODO(ergunsh): Type definitions of some modules do not exist
+// Figure out creating type definitions for them and remove `allowJs` rule
+// We shouldn't need to use Promise<QuantizerModule> below after getting type definitions for imageQuant
 // ImageQuant
 import imageQuant from '../../codecs/imagequant/imagequant_node.js';
 import imageQuantWasm from 'asset-url:../../codecs/imagequant/imagequant_node.wasm';
-const imageQuantPromise = instantiateEmscriptenWasm(imageQuant, imageQuantWasm);
+const imageQuantPromise: Promise<QuantizerModule> = instantiateEmscriptenWasm(
+  imageQuant,
+  imageQuantWasm,
+);
 
 // Our decoders currently rely on a `ImageData` global.
-import ImageData from './image_data.js';
+import ImageData from './image_data';
 globalThis.ImageData = ImageData;
 
-function resizeNameToIndex(name) {
+function resizeNameToIndex(name: string) {
   switch (name) {
     case 'triangle':
       return 0;
@@ -80,25 +109,26 @@ function resizeWithAspect({
   input_height,
   target_width,
   target_height,
-}) {
+}: ResizeWithAspectParams): { width: number; height: number } {
   if (!target_width && !target_height) {
     throw Error('Need to specify at least width or height when resizing');
   }
+
   if (target_width && target_height) {
     return { width: target_width, height: target_height };
   }
+
   if (!target_width) {
     return {
       width: Math.round((input_width / input_height) * target_height),
       height: target_height,
     };
   }
-  if (!target_height) {
+
   return {
     width: target_width,
     height: Math.round((input_height / input_width) * target_width),
   };
-  }
 }
 
 export const preprocessors = {
@@ -108,10 +138,22 @@ export const preprocessors = {
     instantiate: async () => {
       await resizePromise;
       return (
-        buffer,
+        buffer: Uint8Array,
-        input_width,
+        input_width: number,
-        input_height,
+        input_height: number,
-        { width, height, method, premultiply, linearRGB },
+        {
+          width,
+          height,
+          method,
+          premultiply,
+          linearRGB,
+        }: {
+          width: number;
+          height: number;
+          method: string;
+          premultiply: boolean;
+          linearRGB: boolean;
+        },
       ) => {
         ({ width, height } = resizeWithAspect({
           input_width,
@@ -148,7 +190,12 @@ export const preprocessors = {
     description: 'Reduce the number of colors used (aka. paletting)',
     instantiate: async () => {
       const imageQuant = await imageQuantPromise;
-      return (buffer, width, height, { numColors, dither }) =>
+      return (
+        buffer: Uint8Array,
+        width: number,
+        height: number,
+        { numColors, dither }: { numColors: number; dither: number },
+      ) =>
         new ImageData(
           imageQuant.quantize(buffer, width, height, numColors, dither),
           width,
@@ -164,13 +211,18 @@ export const preprocessors = {
     name: 'Rotate',
     description: 'Rotate image',
     instantiate: async () => {
-      return async (buffer, width, height, { numRotations }) => {
+      return async (
+        buffer: Uint8Array,
+        width: number,
+        height: number,
+        { numRotations }: { numRotations: number },
+      ) => {
         const degrees = (numRotations * 90) % 360;
         const sameDimensions = degrees == 0 || degrees == 180;
         const size = width * height * 4;
-        const { instance } = await WebAssembly.instantiate(
+        const instance = (
-          await fsp.readFile(pathify(rotateWasm)),
+          await WebAssembly.instantiate(await fsp.readFile(pathify(rotateWasm)))
-        );
+        ).instance as RotateModuleInstance;
         const { memory } = instance.exports;
         const additionalPagesNeeded = Math.ceil(
           (size * 2 - memory.buffer.byteLength + 8) / (64 * 1024),
@@ -346,13 +398,18 @@ export const codecs = {
       await pngEncDecPromise;
       await oxipngPromise;
       return {
-        encode: (buffer, width, height, opts) => {
+        encode: (
+          buffer: Uint8Array,
+          width: number,
+          height: number,
+          opts: { level: number },
+        ) => {
           const simplePng = pngEncDec.encode(
             new Uint8Array(buffer),
             width,
             height,
           );
-          return oxipng.optimise(simplePng, opts.level);
+          return oxipng.optimise(simplePng, opts.level, false);
         },
       };
     },

libsquoosh/src/emscripten-utils.ts

@@ -1,13 +1,16 @@
 import { fileURLToPath } from 'url';
 
-export function pathify(path) {
+export function pathify(path: string): string {
   if (path.startsWith('file://')) {
     path = fileURLToPath(path);
   }
   return path;
 }
 
-export function instantiateEmscriptenWasm(factory, path) {
+export function instantiateEmscriptenWasm<T extends EmscriptenWasm.Module>(
+  factory: EmscriptenWasm.ModuleFactory<T>,
+  path: string,
+): Promise<T> {
   return factory({
     locateFile() {
       return pathify(path);

libsquoosh/src/image_data.ts

@@ -1,9 +1,13 @@
 export default class ImageData {
-  readonly data: Uint8ClampedArray;
+  readonly data: Uint8ClampedArray | Uint8Array;
   readonly width: number;
   readonly height: number;
 
-  constructor(data: Uint8ClampedArray, width: number, height: number) {
+  constructor(
+    data: Uint8ClampedArray | Uint8Array,
+    width: number,
+    height: number,
+  ) {
     this.data = data;
     this.width = width;
     this.height = height;

libsquoosh/src/missing-types.d.ts

@@ -0,0 +1,166 @@
+/// <reference path="../../missing-types.d.ts" />
+
+declare module 'asset-url:*' {
+  const value: string;
+  export default value;
+}
+
+// Somehow TS picks up definitions from the module itself
+// instead of using `asset-url:*`. It is probably related to
+// specifity of the module declaration and these declarations below fix it
+declare module 'asset-url:../../codecs/png/pkg/squoosh_png_bg.wasm' {
+  const value: string;
+  export default value;
+}
+
+declare module 'asset-url:../../codecs/oxipng/pkg/squoosh_oxipng_bg.wasm' {
+  const value: string;
+  export default value;
+}
+
+// These don't exist in NodeJS types so we're not able to use them but they are referenced in some emscripten and codec types
+// Thus, we need to explicitly assign them to be `never`
+// We're also not able to use the APIs that use these types
+// So, if we want to use those APIs we need to supply its dependencies ourselves
+// However, probably those APIs are more suited to be used in web (i.e. there can be other
+// dependencies to web APIs that might not work in Node)
+type RequestInfo = never;
+type Response = never;
+type WebGLRenderingContext = never;
+type MessageEvent = never;
+
+type BufferSource = ArrayBufferView | ArrayBuffer;
+type URL = import('url').URL;
+
+/**
+ * WebAssembly definitions are not available in `@types/node` yet,
+ * so these are copied from `lib.dom.d.ts`
+ */
+declare namespace WebAssembly {
+  interface CompileError {}
+
+  var CompileError: {
+    prototype: CompileError;
+    new (): CompileError;
+  };
+
+  interface Global {
+    value: any;
+    valueOf(): any;
+  }
+
+  var Global: {
+    prototype: Global;
+    new (descriptor: GlobalDescriptor, v?: any): Global;
+  };
+
+  interface Instance {
+    readonly exports: Exports;
+  }
+
+  var Instance: {
+    prototype: Instance;
+    new (module: Module, importObject?: Imports): Instance;
+  };
+
+  interface LinkError {}
+
+  var LinkError: {
+    prototype: LinkError;
+    new (): LinkError;
+  };
+
+  interface Memory {
+    readonly buffer: ArrayBuffer;
+    grow(delta: number): number;
+  }
+
+  var Memory: {
+    prototype: Memory;
+    new (descriptor: MemoryDescriptor): Memory;
+  };
+
+  interface Module {}
+
+  var Module: {
+    prototype: Module;
+    new (bytes: BufferSource): Module;
+    customSections(moduleObject: Module, sectionName: string): ArrayBuffer[];
+    exports(moduleObject: Module): ModuleExportDescriptor[];
+    imports(moduleObject: Module): ModuleImportDescriptor[];
+  };
+
+  interface RuntimeError {}
+
+  var RuntimeError: {
+    prototype: RuntimeError;
+    new (): RuntimeError;
+  };
+
+  interface Table {
+    readonly length: number;
+    get(index: number): Function | null;
+    grow(delta: number): number;
+    set(index: number, value: Function | null): void;
+  }
+
+  var Table: {
+    prototype: Table;
+    new (descriptor: TableDescriptor): Table;
+  };
+
+  interface GlobalDescriptor {
+    mutable?: boolean;
+    value: ValueType;
+  }
+
+  interface MemoryDescriptor {
+    initial: number;
+    maximum?: number;
+  }
+
+  interface ModuleExportDescriptor {
+    kind: ImportExportKind;
+    name: string;
+  }
+
+  interface ModuleImportDescriptor {
+    kind: ImportExportKind;
+    module: string;
+    name: string;
+  }
+
+  interface TableDescriptor {
+    element: TableKind;
+    initial: number;
+    maximum?: number;
+  }
+
+  interface WebAssemblyInstantiatedSource {
+    instance: Instance;
+    module: Module;
+  }
+
+  type ImportExportKind = 'function' | 'global' | 'memory' | 'table';
+  type TableKind = 'anyfunc';
+  type ValueType = 'f32' | 'f64' | 'i32' | 'i64';
+  type ExportValue = Function | Global | Memory | Table;
+  type Exports = Record<string, ExportValue>;
+  type ImportValue = ExportValue | number;
+  type ModuleImports = Record<string, ImportValue>;
+  type Imports = Record<string, ModuleImports>;
+  function compile(bytes: BufferSource): Promise<Module>;
+  // `compileStreaming` does not exist in NodeJS
+  // function compileStreaming(source: Response | Promise<Response>): Promise<Module>;
+  function instantiate(
+    bytes: BufferSource,
+    importObject?: Imports,
+  ): Promise<WebAssemblyInstantiatedSource>;
+  function instantiate(
+    moduleObject: Module,
+    importObject?: Imports,
+  ): Promise<Instance>;
+  // `instantiateStreaming` does not exist in NodeJS
+  // function instantiateStreaming(response: Response | PromiseLike<Response>, importObject?: Imports): Promise<WebAssemblyInstantiatedSource>;
+  function validate(bytes: BufferSource): boolean;
+}

libsquoosh/tsconfig.json

@@ -2,7 +2,8 @@
   "extends": "../generic-tsconfig.json",
   "compilerOptions": {
     "lib": ["esnext"],
-    "types": ["node"]
+    "types": ["node"],
+    "allowJs": true
   },
-  "include": ["src/**/*"]
+  "include": ["src/**/*", "../codecs/**/*"]
 }