Create wasm-in-wasm-imports example (#2229)

rustwasm · Jul 8, 2020 · 1795020 · 1795020
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diff --git a/Cargo.toml b/Cargo.toml
@@ -79,6 +79,7 @@ members = [
   "examples/request-animation-frame",
   "examples/todomvc",
   "examples/wasm-in-wasm",
+  "examples/wasm-in-wasm-imports",
   "examples/wasm2js",
   "examples/webaudio",
   "examples/webgl",

diff --git a/examples/wasm-in-wasm-imports/Cargo.toml b/examples/wasm-in-wasm-imports/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "wasm-in-wasm-imports"
+version = "0.1.0"
+authors = ["The wasm-bindgen Developers"]
+edition = "2018"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+wasm-bindgen = "0.2.64"
+js-sys = "0.3.41"
+wasm-bindgen-futures = "0.4.14"
diff --git a/examples/wasm-in-wasm-imports/README.md b/examples/wasm-in-wasm-imports/README.md
@@ -0,0 +1,15 @@
+# js-sys: WebAssembly in WebAssembly
+
+[View documentation for this example online][dox] or [View compiled example
+online][compiled]
+
+[compiled]: https://rustwasm.github.io/wasm-bindgen/exbuild/wasm-in-wasm/
+[dox]: https://rustwasm.github.io/docs/wasm-bindgen/examples/wasm-in-wasm.html
+
+You can build the example locally with:
+
+```
+$ npm run serve
+```
+
+and then visiting http://localhost:8080 in a browser should run the example!
diff --git a/examples/wasm-in-wasm-imports/index.html b/examples/wasm-in-wasm-imports/index.html
@@ -0,0 +1,8 @@
+<html>
+  <head>
+    <meta content="text/html;charset=utf-8" http-equiv="Content-Type"/>
+  </head>
+  <body>
+    <p>The developer console should have messages in it</p>
+  </body>
+</html>
diff --git a/examples/wasm-in-wasm-imports/index.js b/examples/wasm-in-wasm-imports/index.js
@@ -0,0 +1,4 @@
+// For more comments about what's going on here, check out the `hello_world`
+// example
+import('./pkg')
+  .catch(console.error);
diff --git a/examples/wasm-in-wasm-imports/package.json b/examples/wasm-in-wasm-imports/package.json
@@ -0,0 +1,14 @@
+{
+  "scripts": {
+    "build": "webpack",
+    "serve": "webpack-dev-server"
+  },
+  "devDependencies": {
+    "@wasm-tool/wasm-pack-plugin": "1.0.1",
+    "text-encoding": "^0.7.0",
+    "html-webpack-plugin": "^3.2.0",
+    "webpack": "^4.29.4",
+    "webpack-cli": "^3.1.1",
+    "webpack-dev-server": "^3.1.0"
+  }
+}
diff --git a/examples/wasm-in-wasm-imports/src/lib.rs b/examples/wasm-in-wasm-imports/src/lib.rs
@@ -0,0 +1,86 @@
+use js_sys::{Function, Map, Object, Reflect, WebAssembly};
+use wasm_bindgen::prelude::*;
+use wasm_bindgen::JsCast;
+use wasm_bindgen_futures::{spawn_local, JsFuture};
+
+#[wasm_bindgen]
+extern "C" {
+    #[wasm_bindgen(js_namespace = console)]
+    pub(crate) fn log(a: &str);
+
+    #[wasm_bindgen(js_namespace = console)]
+    pub(crate) fn error(a: &str);
+
+}
+
+#[macro_use]
+macro_rules! console_log {
+    ($($t:tt)*) => (log(&format_args!($($t)*).to_string()))
+}
+
+#[macro_use]
+macro_rules! console_error {
+    ($($t:tt)*) => (log(&format_args!($($t)*).to_string()))
+}
+
+const WASM: &[u8] = include_bytes!("native_add.wasm");
+
+async fn run_async() -> Result<(), JsValue> {
+    console_log!("instantiating a new wasm module directly");
+
+    let imports = make_imports()?;
+    let a = JsFuture::from(WebAssembly::instantiate_buffer(WASM, &imports)).await?;
+
+    let instance: WebAssembly::Instance = Reflect::get(&a, &"instance".into())?.dyn_into()?;
+
+    let exports = instance.exports();
+
+    let add = Reflect::get(&exports, &"add".into())?
+        .dyn_into::<Function>()
+        .expect("add export wasn't a function");
+
+    let three = add.call2(&JsValue::undefined(), &1.into(), &2.into())?;
+    console_log!("1 + 2 = {:?}", three);
+
+    Ok(())
+}
+
+fn bind(this: &JsValue, func_name: &str) -> Result<(), JsValue> {
+    let property_key = JsValue::from(func_name);
+    let orig_func = Reflect::get(this, &property_key)?.dyn_into::<Function>()?;
+    let func = orig_func.bind(this);
+    if !Reflect::set(this, &property_key, &func)? {
+        return Err(JsValue::from("failed to set property"));
+    }
+    Ok(())
+}
+
+pub fn make_imports() -> Result<Object, JsValue> {
+    let map = Map::new();
+    let imports: JsValue = Imports.into();
+
+    bind(&imports, "native_add")?;
+
+    map.set(&JsValue::from("env"), &imports);
+    Object::from_entries(&map.into())
+}
+
+#[wasm_bindgen]
+pub struct Imports;
+
+#[wasm_bindgen]
+impl Imports {
+    pub fn native_add(&self, a: i32, b: i32) -> i32 {
+        a + b
+    }
+}
+
+#[wasm_bindgen(start)]
+pub fn run() {
+    spawn_local(async {
+        match run_async().await {
+            Ok(_) => console_log!("Finished"),
+            Err(e) => console_error!("{:?}", e),
+        }
+    });
+}
diff --git a/examples/wasm-in-wasm-imports/src/native_add.wasm b/examples/wasm-in-wasm-imports/src/native_add.wasm
diff --git a/examples/wasm-in-wasm-imports/webpack.config.js b/examples/wasm-in-wasm-imports/webpack.config.js
@@ -0,0 +1,27 @@
+const path = require('path');
+const HtmlWebpackPlugin = require('html-webpack-plugin');
+const webpack = require('webpack');
+const WasmPackPlugin = require("@wasm-tool/wasm-pack-plugin");
+
+module.exports = {
+    entry: './index.js',
+    output: {
+        path: path.resolve(__dirname, 'dist'),
+        filename: 'index.js',
+    },
+    plugins: [
+        new HtmlWebpackPlugin({
+            template: 'index.html'
+        }),
+        new WasmPackPlugin({
+            crateDirectory: path.resolve(__dirname, ".")
+        }),
+        // Have this example work in Edge which doesn't ship `TextEncoder` or
+        // `TextDecoder` at this time.
+        new webpack.ProvidePlugin({
+          TextDecoder: ['text-encoding', 'TextDecoder'],
+          TextEncoder: ['text-encoding', 'TextEncoder']
+        })
+    ],
+    mode: 'development'
+};