feat: add experimental inline node target

crates/cli-support/src/js/mod.rs

@@ -142,7 +142,7 @@ impl<'a> Context<'a> {
             self.globals.push_str(c);
         }
         let global = match self.config.mode {
-            OutputMode::Node { module: false } => {
+            OutputMode::InlineNodeJs | OutputMode::Node { module: false } => {
                 if contents.starts_with("class") {
                     format!("{}\nmodule.exports.{1} = {1};\n", contents, export_name)
                 } else {
@@ -291,6 +291,31 @@ impl<'a> Context<'a> {
         reset_indentation(&shim)
     }
 
+    fn generate_isomorphic_wasm_loading(&mut self) -> String {
+        let mut shim = String::new();
+
+        let buf = self.module.emit_wasm();
+
+        let mut serialized = "const bytes = Buffer.from([".to_string();
+        let (last, bytes) = buf.split_last().unwrap();
+        for byte in bytes {
+            serialized.push_str(&format!("{},", byte));
+        }
+        serialized.push_str(&format!("{}", last));
+        serialized.push_str("]);");
+        shim.push_str(&serialized);
+        shim.push_str(
+            "
+                const wasmModule = new WebAssembly.Module(bytes);
+                const wasmInstance = new WebAssembly.Instance(wasmModule, imports);
+                wasm = wasmInstance.exports;
+                module.exports.__wasm = wasm;
+            ",
+        );
+
+        reset_indentation(&shim)
+    }
+
     // generates something like
     // ```js
     // import * as import0 from './snippets/.../inline1.js';
@@ -500,6 +525,32 @@ impl<'a> Context<'a> {
                 footer.push_str("export { initSync };\n");
                 footer.push_str("export default __wbg_init;");
             }
+
+            OutputMode::InlineNodeJs => {
+                js.push_str(&self.generate_node_imports());
+
+                js.push_str("let wasm;\n");
+
+                for (id, js) in crate::sorted_iter(&self.wasm_import_definitions) {
+                    let import = self.module.imports.get_mut(*id);
+                    footer.push_str("\nmodule.exports.");
+                    footer.push_str(&import.name);
+                    footer.push_str(" = ");
+                    footer.push_str(js.trim());
+                    footer.push_str(";\n");
+                }
+
+                footer.push_str(
+                    &self.generate_node_wasm_loading(Path::new(&format!(
+                        "./{}_bg.wasm",
+                        module_name
+                    ))),
+                );
+
+                if needs_manual_start {
+                    footer.push_str("\nwasm.__wbindgen_start();\n");
+                }
+            }
         }
 
         // Before putting the static init code declaration info, put all existing typescript into a `wasm_bindgen` namespace declaration.
@@ -568,7 +619,7 @@ impl<'a> Context<'a> {
                 }
             }
 
-            OutputMode::Node { module: false } => {
+            OutputMode::InlineNodeJs | OutputMode::Node { module: false } => {
                 for (module, items) in crate::sorted_iter(&self.js_imports) {
                     imports.push_str("const { ");
                     for (i, (item, rename)) in items.iter().enumerate() {
@@ -1043,7 +1094,7 @@ impl<'a> Context<'a> {
             */\n  toString(): string;\n",
             );
 
-            if self.config.mode.nodejs() {
+            if self.config.mode.nodejs() || self.config.mode.inline_nodejs() {
                 // `util.inspect` must be imported in Node.js to define [inspect.custom]
                 let module_name = self.import_name(&JsImport {
                     name: JsImportName::Module {
@@ -1522,7 +1573,8 @@ impl<'a> Context<'a> {
         init: Option<&str>,
     ) -> Result<(), Error> {
         match &self.config.mode {
-            OutputMode::Node { .. } => {
+
+            OutputMode::InlineNodeJs | OutputMode::Node { .. } => {
                 let name = self.import_name(&JsImport {
                     name: JsImportName::Module {
                         module: "util".to_string(),
@@ -1555,6 +1607,7 @@ impl<'a> Context<'a> {
         if let Some(init) = init {
             match &self.config.mode {
                 OutputMode::Node { .. }
+                | OutputMode::InlineNodeJs
                 | OutputMode::Bundler {
                     browser_only: false,
                 } => self.global(init),
@@ -3244,7 +3297,7 @@ impl<'a> Context<'a> {
                         | OutputMode::Bundler { .. }
                         | OutputMode::Deno
                         | OutputMode::Node { module: true } => "import.meta.url",
-                        OutputMode::Node { module: false } => {
+                        OutputMode::InlineNodeJs | OutputMode::Node { module: false } => {
                             "require('url').pathToFileURL(__filename)"
                         }
                         OutputMode::NoModules { .. } => {

crates/cli-support/src/lib.rs

@@ -68,6 +68,7 @@ enum OutputMode {
     NoModules { global: String },
     Node { module: bool },
     Deno,
+    InlineNodeJs,
 }
 
 enum Input {
@@ -169,6 +170,16 @@ impl Bindgen {
         Ok(self)
     }
 
+    pub fn inline_nodejs(&mut self, inline_nodejs: bool) -> Result<&mut Bindgen, Error> {
+        if inline_nodejs {
+            self.switch_mode(
+                OutputMode::InlineNodeJs,
+                "--target experimental-inline-nodejs",
+            )?;
+        }
+        Ok(self)
+    }
+
     pub fn bundler(&mut self, bundler: bool) -> Result<&mut Bindgen, Error> {
         if bundler {
             self.switch_mode(
@@ -544,6 +555,10 @@ impl OutputMode {
         matches!(self, OutputMode::Node { .. })
     }
 
+    fn inline_nodejs(&self) -> bool {
+        matches!(self, OutputMode::InlineNodeJs)
+    }
+
     fn no_modules(&self) -> bool {
         matches!(self, OutputMode::NoModules { .. })
     }

crates/cli/src/bin/wasm-bindgen.rs

@@ -110,6 +110,7 @@ fn rmain(args: &Args) -> Result<(), Error> {
             "nodejs" => b.nodejs(true)?,
             "deno" => b.deno(true)?,
             "experimental-nodejs-module" => b.nodejs_module(true)?,
+            "experimental-inline-nodejs" => b.inline_nodejs(true)?,
             s => bail!("invalid encode-into mode: `{}`", s),
         };
     }