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You can use cpp.js to compile native code from your project into WebAssembly. To do this, add the build script and cpp.js as a dependency in the package.json file of your project.

package.json
{
    "name": "myapp",
    "scripts": {
+       "build": "cpp.js generate lib -p wasm",
        "dev": "wrangler dev",
        "deploy": "wrangler dev"
    },
    "devDependencies": {
+       "cpp.js": "^1.0.0-beta.1",
        "wrangler": "^3.75.0"
    }
}

To install the npm packages, use the following command:

npm install

Cpp.js requires a configuration file to work. For a minimal setup, create a cppjs.config.mjs file and add the following content.

cppjs.config.mjs
import getDirName from 'cpp.js/src/utils/getDirName.js';

export default {
    paths: {
        project: getDirName(import.meta.url),
        output: 'dist',
    },
};

Move your C++ code to the src/native directory. For example;

src/native/MySampleClass.h
#pragma once
#include <string>

class MySampleClass {
public:
    static std::string sample() {
        return "Hello World!";
    }
};

#endif

Now, we can compile our C++ code into WebAssembly. Run the following command:

warning

Before proceeding, ensure that you have met all the prerequisites for setting up a working development environment.

npm run build

This command will generate myapp.wasm, myapp.browser.js, and myapp.node.js files inside the dist folder.

├── src
│   └── native
|       └── MySampleClass.h
|
├── dist
│   └── myapp.wasm
|   └── myapp.browser.js
|   └── myapp.node.js
├── ...

You can now access your native code by importing dist/myapp.browser.js into your JavaScript file. For a minimal setup, create a index.js and add the following content.

index.js
import initCppJs from './dist/myapp.browser.js';
import wasmContent from './dist/myapp.wasm';

const { MySampleClass } = await initCppJs({ getWasmFunction: () => wasmContent });

export default {
    async fetch(request, env, ctx) {
        return new Response(MySampleClass.sample());
    },
};

The project is now fully set up and ready to run. To view the output, run the following command:

npm run dev

To deploy the output, run the following command:

npm run deploy
info

Sample Source Code: You can access the sample source code from this link.