Refactor wasm initialization

.eslintrc.js

@@ -2,8 +2,7 @@ module.exports = {
     env: {
       browser: true,
       es6: true,
-      commonjs: true,
-      jest: true
+      commonjs: true
     },
     root: true,
     extends: [
@@ -78,4 +77,4 @@ module.exports = {
         }
       ]
     }
-  };
+  };

.github/workflows/main.yml

@@ -35,7 +35,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v2
         with:
-          node-version: '16' 
+          node-version: '16'
 
       - name: Install dependencies
         run: yarn install
@@ -51,9 +51,3 @@ jobs:
           micromamba activate untarjs
 
           yarn run eslint
-
-      - name: Run test
-        run: |
-          micromamba activate untarjs
-
-          yarn run test

README.md

@@ -18,7 +18,9 @@ This package has 2 methods:
 
 The example of using:
 ```sh
-import untarjs from "@emscripten-forge/untarjs";
+import { initUntarJS } from "@emscripten-forge/untarjs";
+
+const untarjs = await initUntarJS();
 
 const condaPackageUrl = 'https://conda.anaconda.org/conda-forge/linux-64/_libgcc_mutex-0.1-conda_forge.tar.bz2';
 untarjs.extract(condaPackageUrl).then((files)=>{

package.json

@@ -12,8 +12,7 @@
     "prettier": "prettier --list-different --write \"src/**/*.ts\"",
     "prettier:check": "prettier --check \"src/**/*.ts\"",
     "eslint": "eslint --ext .ts --fix .",
-    "eslint:check": "eslint --ext .ts.",
-    "test": "jest"
+    "eslint:check": "eslint --ext .ts."
   },
   "files": [
     "lib/"
@@ -45,20 +44,16 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.13.0",
-    "@types/jest": "^29.5.14",
     "@types/node": "^22.8.1",
     "@typescript-eslint/eslint-plugin": "~6.13.2",
     "@typescript-eslint/parser": "~6.13.2",
     "eslint": "~8.55.0",
     "eslint-config-prettier": "~9.1.0",
-    "eslint-plugin-jest": "~27.6.0",
     "eslint-plugin-prettier": "~5.0.1",
     "eslint-plugin-react": "~7.33.2",
     "globals": "^15.11.0",
-    "jest": "^29.7.0",
     "prettier": "^3.3.3",
     "rimraf": "^3.0.2",
-    "ts-jest": "^29.2.5",
     "typescript": "^5",
     "typescript-eslint": "^8.12.2"
   }

src/helper.ts

@@ -1,21 +1,17 @@
 import unpack, { IWasmModule } from './unpack';
 import unpackWasm from './unpack.wasm';
 
-const initializeWasm = async (): Promise<IWasmModule | undefined> => {
-  try {
-    const wasmModule: IWasmModule = await unpack({
-      locateFile(path: string) {
-        if (path.endsWith('.wasm')) {
-          return unpackWasm;
-        }
-        return path;
+const initializeWasm = async (): Promise<IWasmModule> => {
+  const wasmModule: IWasmModule = await unpack({
+    locateFile(path: string) {
+      if (path.endsWith('.wasm')) {
+        return unpackWasm;
       }
-    });
+      return path;
+    }
+  });
 
-    return wasmModule;
-  } catch (err) {
-    console.error('Error initializing the WASM module:', err);
-    return undefined;
-  }
+  return wasmModule;
 };
+
 export default initializeWasm;

src/index.ts

@@ -1,6 +1,5 @@
 import initializeWasm from './helper';
-import { IFileData } from './types';
-import { IWasmModule } from './unpack';
+import { IFileData, IUnpackJSAPI } from './types';
 
 const fetchByteArray = async (url: string): Promise<Uint8Array> => {
   const response = await fetch(url);
@@ -11,138 +10,125 @@ const fetchByteArray = async (url: string): Promise<Uint8Array> => {
   return new Uint8Array(arrayBuffer);
 };
 
- const init = async (): Promise<IWasmModule | null> => {
-  try {
-    const wasmModule = await initializeWasm();
-    return wasmModule as IWasmModule;
-  } catch (error) {
-    console.error('Error initializing WASM module:', error);
-    return null;
-  }
-};
-
-export const extractData = async (data: Uint8Array): Promise<IFileData[]> => {
-  const wasmModule = await init();
-  if (!wasmModule) {
-    console.error('WASM module not initialized.');
-    return [];
-  }
-
-  /**Since WebAssembly, memory is accessed using pointers 
-    and the first parameter of extract_archive method from unpack.c, which is Uint8Array of file data, should be a pointer 
-    so we have to allocate memory for file data
-  **/
-  const inputPtr = wasmModule._malloc(data.length);
-  wasmModule.HEAPU8.set(data, inputPtr);
-
-  // fileCountPtr is the pointer to 4 bytes of memory in WebAssembly's heap that holds fileCount value from the ExtractedArchive structure in unpack.c.
-  const fileCountPtr = wasmModule._malloc(4);
-
-  try {
-    const resultPtr = wasmModule._extract_archive(
-      inputPtr,
-      data.length,
-      fileCountPtr
-    );
-
-    /**
-     * Since extract_archive returns a pointer that refers to an instance of the ExtractedArchive in unpack.c
-        typedef struct {
-          FileData* files;
-          size_t fileCount;
-          int status;
-          char* error_message; 
-        } ExtractedArchive;
-
-      its fields are laid out in memory sequentially. Based on this and types each field will take 4 bytes:
-
-          4 bytes        4 bytes         4 bytes         4 bytes
-      ---------------|---------------|---------------|---------------
-     files            fileCount         status        error_message
-
-      `resultPtr` points to the beginning of the ExtractedArchive structure in WebAssembly memory 
-      and in order to get pointer of statusPtr we need to calculate it as: 0(offset of file pointer) + 4 (offset of fileCount) + 4 (offset for status)
-      'status' field and pointer of `error_message` are 32-bit signed integer
-    */
-    const statusPtr = wasmModule.getValue(resultPtr + 8, 'i32');
-    const errorMessagePtr = wasmModule.getValue(resultPtr + 12, 'i32');
-    if (statusPtr !== 1) {
-      const errorMessage = wasmModule.UTF8ToString(errorMessagePtr);
-      console.error(
-        'Extraction failed with status:',
-        statusPtr,
-        'Error:',
-        errorMessage
+export const initUntarJS = async (): Promise<IUnpackJSAPI> => {
+  const wasmModule = await initializeWasm();
+
+  const extractData = async (data: Uint8Array): Promise<IFileData[]> => {
+    /**Since WebAssembly, memory is accessed using pointers
+      and the first parameter of extract_archive method from unpack.c, which is Uint8Array of file data, should be a pointer
+      so we have to allocate memory for file data
+    **/
+    const inputPtr = wasmModule._malloc(data.length);
+    wasmModule.HEAPU8.set(data, inputPtr);
+
+    // fileCountPtr is the pointer to 4 bytes of memory in WebAssembly's heap that holds fileCount value from the ExtractedArchive structure in unpack.c.
+    const fileCountPtr = wasmModule._malloc(4);
+
+    try {
+      const resultPtr = wasmModule._extract_archive(
+        inputPtr,
+        data.length,
+        fileCountPtr
       );
+
+      /**
+       * Since extract_archive returns a pointer that refers to an instance of the ExtractedArchive in unpack.c
+          typedef struct {
+            FileData* files;
+            size_t fileCount;
+            int status;
+            char* error_message;
+          } ExtractedArchive;
+
+        its fields are laid out in memory sequentially. Based on this and types each field will take 4 bytes:
+
+            4 bytes        4 bytes         4 bytes         4 bytes
+        ---------------|---------------|---------------|---------------
+      files            fileCount         status        error_message
+
+        `resultPtr` points to the beginning of the ExtractedArchive structure in WebAssembly memory
+        and in order to get pointer of statusPtr we need to calculate it as: 0(offset of file pointer) + 4 (offset of fileCount) + 4 (offset for status)
+        'status' field and pointer of `error_message` are 32-bit signed integer
+      */
+      const statusPtr = wasmModule.getValue(resultPtr + 8, 'i32');
+      const errorMessagePtr = wasmModule.getValue(resultPtr + 12, 'i32');
+      if (statusPtr !== 1) {
+        const errorMessage = wasmModule.UTF8ToString(errorMessagePtr);
+        console.error(
+          'Extraction failed with status:',
+          statusPtr,
+          'Error:',
+          errorMessage
+        );
+        return [];
+      }
+      const filesPtr = wasmModule.getValue(resultPtr, 'i32');
+      const fileCount = wasmModule.getValue(resultPtr + 4, 'i32');
+
+      const files: IFileData[] = [];
+
+      /**
+       * FilesPtr is a pointer that refers to an instance of the FileData in unpack.c
+          typedef struct {
+            char* filename;
+            uint8_t* data;
+            size_t data_size;
+          } FileData;
+
+        and its fields are laid out in memory sequentially too so each field take 4 bytes:
+
+            4 bytes        4 bytes         4 bytes
+        ---------------|---------------|---------------
+      filename            data         data_size
+
+      `filesPtr + i * 12` calculates the memory address of the i-th FileData element in the array
+        where `12` is the size of each FileData structure in memory in bytes: 4 + 4 + 4
+      */
+
+      for (let i = 0; i < fileCount; i++) {
+        const fileDataPtr = filesPtr + i * 12;
+        const filenamePtr = wasmModule.getValue(fileDataPtr, 'i32');
+        const dataSize = wasmModule.getValue(fileDataPtr + 8, 'i32');
+        const dataPtr = wasmModule.getValue(fileDataPtr + 4, 'i32');
+        const filename = wasmModule.UTF8ToString(filenamePtr);
+        const fileData = new Uint8Array(
+          wasmModule.HEAPU8.buffer,
+          dataPtr,
+          dataSize
+        );
+
+        files.push({
+          filename: filename,
+          data: fileData
+        });
+      }
+
+      wasmModule._free(inputPtr);
+      wasmModule._free(fileCountPtr);
+      wasmModule._free(errorMessagePtr);
+      wasmModule._free(resultPtr);
+
+      return files;
+    } catch (error) {
+      console.error('Error during extraction:', error);
       return [];
     }
-    const filesPtr = wasmModule.getValue(resultPtr, 'i32');
-    const fileCount = wasmModule.getValue(resultPtr + 4, 'i32');
-
-    const files: IFileData[] = [];
-
-    /**
-     * FilesPtr is a pointer that refers to an instance of the FileData in unpack.c
-        typedef struct {
-          char* filename;
-          uint8_t* data;
-          size_t data_size;
-        } FileData;
-
-      and its fields are laid out in memory sequentially too so each field take 4 bytes:
-
-          4 bytes        4 bytes         4 bytes     
-      ---------------|---------------|---------------
-     filename            data         data_size        
-
-     `filesPtr + i * 12` calculates the memory address of the i-th FileData element in the array
-      where `12` is the size of each FileData structure in memory in bytes: 4 + 4 + 4
-    */
-
-    for (let i = 0; i < fileCount; i++) {
-      const fileDataPtr = filesPtr + i * 12;
-      const filenamePtr = wasmModule.getValue(fileDataPtr, 'i32');
-      const dataSize = wasmModule.getValue(fileDataPtr + 8, 'i32');
-      const dataPtr = wasmModule.getValue(fileDataPtr + 4, 'i32');
-      const filename = wasmModule.UTF8ToString(filenamePtr);
-      const fileData = new Uint8Array(
-        wasmModule.HEAPU8.buffer,
-        dataPtr,
-        dataSize
-      );
-
-      files.push({
-        filename: filename,
-        data: fileData
-      });
+  };
+
+  const extract = async (url: string): Promise<IFileData[]> => {
+    try {
+      const data = await fetchByteArray(url);
+      return await extractData(data);
+    } catch (error) {
+      console.error('Error during extracting:', error);
+      return [];
     }
-
-    wasmModule._free(inputPtr);
-    wasmModule._free(fileCountPtr);
-    wasmModule._free(errorMessagePtr);
-    wasmModule._free(resultPtr);
-
-    return files;
-  } catch (error) {
-    console.error('Error during extraction:', error);
-    return [];
   }
-};
 
-export const extract = async (url: string): Promise<IFileData[]> => {
-  try {
-    const data = await fetchByteArray(url);
-    return await extractData(data);
-  } catch (error) {
-    console.error('Error during extracting:', error);
-    return [];
-  }
+  return {
+    extract,
+    extractData
+  };
 };
 
-
 export * from './types';
-
-export default {
-  extract,
-  extractData
-};

src/types.ts

@@ -2,3 +2,8 @@ export interface IFileData {
   filename: string;
   data: Uint8Array;
 }
+
+export interface IUnpackJSAPI {
+  extractData: (data: Uint8Array) => Promise<IFileData[]>;
+  extract: (url: string) => Promise<IFileData[]>;
+}