feat: add wasm fallback plugin (#1957)

resolves #1919

Cargo.toml

@@ -91,6 +91,7 @@ rolldown_plugin_manifest                = { version = "0.1.0", path = "./crates/
 rolldown_plugin_module_preload_polyfill = { version = "0.1.0", path = "./crates/rolldown_plugin_module_preload_polyfill" }
 rolldown_plugin_transform               = { version = "0.1.0", path = "./crates/rolldown_plugin_transform" }
 rolldown_plugin_wasm                    = { version = "0.1.0", path = "./crates/rolldown_plugin_wasm" }
+rolldown_plugin_wasm_fallback           = { version = "0.1.0", path = "./crates/rolldown_plugin_wasm_fallback" }
 rolldown_resolver                       = { version = "0.1.0", path = "./crates/rolldown_resolver" }
 rolldown_rstr                           = { version = "0.1.0", path = "./crates/rolldown_rstr" }
 rolldown_sourcemap                      = { version = "0.1.0", path = "./crates/rolldown_sourcemap" }

crates/rolldown_binding/Cargo.toml

@@ -34,6 +34,7 @@ rolldown_plugin_manifest                = { workspace = true }
 rolldown_plugin_module_preload_polyfill = { workspace = true }
 rolldown_plugin_transform               = { workspace = true }
 rolldown_plugin_wasm                    = { workspace = true }
+rolldown_plugin_wasm_fallback           = { workspace = true }
 rolldown_sourcemap                      = { workspace = true }
 rolldown_tracing                        = { workspace = true }
 rolldown_utils                          = { workspace = true }

crates/rolldown_binding/src/options/plugin/binding_builtin_plugin.rs

@@ -10,6 +10,7 @@ use rolldown_plugin_manifest::{ManifestPlugin, ManifestPluginConfig};
 use rolldown_plugin_module_preload_polyfill::ModulePreloadPolyfillPlugin;
 use rolldown_plugin_transform::{StringOrRegex, TransformPlugin};
 use rolldown_plugin_wasm::WasmPlugin;
+use rolldown_plugin_wasm_fallback::WasmFallbackPlugin;
 use serde::Deserialize;
 use std::sync::Arc;
 
@@ -45,6 +46,7 @@ pub enum BindingBuiltinPluginName {
   ManifestPlugin,
   LoadFallbackPlugin,
   TransformPlugin,
+  WasmFallbackPlugin,
 }
 
 #[napi_derive::napi(object)]
@@ -132,6 +134,7 @@ impl TryFrom<BindingBuiltinPlugin> for Arc<dyn Pluginable> {
   fn try_from(plugin: BindingBuiltinPlugin) -> Result<Self, Self::Error> {
     Ok(match plugin.__name {
       BindingBuiltinPluginName::WasmPlugin => Arc::new(WasmPlugin {}),
+      BindingBuiltinPluginName::WasmFallbackPlugin => Arc::new(WasmFallbackPlugin {}),
       BindingBuiltinPluginName::ImportGlobPlugin => {
         let config = if let Some(options) = plugin.options {
           BindingGlobImportPluginConfig::from_unknown(options)?.into()

crates/rolldown_plugin_wasm_fallback/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+edition.workspace    = true
+homepage.workspace   = true
+license.workspace    = true
+name                 = "rolldown_plugin_wasm_fallback"
+repository.workspace = true
+version              = "0.1.0"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+doctest = false
+
+[lints]
+workspace = true
+
+[dependencies]
+anyhow          = { workspace = true }
+rolldown_plugin = { workspace = true }

crates/rolldown_plugin_wasm_fallback/src/lib.rs

@@ -0,0 +1,27 @@
+use std::borrow::Cow;
+
+use rolldown_plugin::{HookLoadArgs, HookLoadReturn, Plugin, SharedPluginContext};
+
+#[derive(Debug)]
+pub struct WasmFallbackPlugin {}
+
+impl Plugin for WasmFallbackPlugin {
+  fn name(&self) -> Cow<'static, str> {
+    Cow::Borrowed("builtin:wasm-fallback-plugin")
+  }
+
+  #[allow(clippy::case_sensitive_file_extension_comparisons)]
+  async fn load(&self, _ctx: &SharedPluginContext, args: &HookLoadArgs<'_>) -> HookLoadReturn {
+    if args.id.ends_with(".wasm") {
+      // TODO: Replace the link here after rolldown's document is ready
+      Err(anyhow::anyhow!(
+        "\"ESM integration proposal for Wasm\" is not supported currently.
+        Use plugin-wasm or other community plugins to handle this.
+        Alternatively, you can use `.wasm?init` or `.wasm?url`.
+        See https://vitejs.dev/guide/features.html#webassembly for more details."
+      ))
+    } else {
+      Ok(None)
+    }
+  }
+}

packages/rolldown/src/binding.d.ts

@@ -117,7 +117,8 @@ export declare enum BindingBuiltinPluginName {
   ModulePreloadPolyfillPlugin = 3,
   ManifestPlugin = 4,
   LoadFallbackPlugin = 5,
-  TransformPlugin = 6
+  TransformPlugin = 6,
+  WasmFallbackPlugin = 7
 }
 
 export interface BindingEmittedAsset {

packages/rolldown/src/experimental-index.ts

@@ -7,6 +7,7 @@ export {
   modulePreloadPolyfillPlugin,
   dynamicImportVarsPlugin,
   wasmPlugin,
+  wasmFallbackPlugin,
   importGlobPlugin,
   manifestPlugin,
   loadFallbackPlugin,

packages/rolldown/src/plugin/builtin-plugin.ts

@@ -50,6 +50,12 @@ export class WasmPlugin extends BuiltinPlugin {
   }
 }
 
+export class WasmFallbackPlugin extends BuiltinPlugin {
+  constructor() {
+    super(BindingBuiltinPluginName.WasmFallbackPlugin)
+  }
+}
+
 export class LoadFallbackPlugin extends BuiltinPlugin {
   constructor() {
     super(BindingBuiltinPluginName.LoadFallbackPlugin)
@@ -85,6 +91,10 @@ export function wasmPlugin() {
   return new WasmPlugin()
 }
 
+export function wasmFallbackPlugin() {
+  return new WasmFallbackPlugin()
+}
+
 export function transformPlugin(config?: TransformPluginConfig) {
   return new TransformPlugin(config)
 }

packages/rolldown/tests/fixture.test.ts

@@ -22,8 +22,14 @@ function main() {
         const output = await compileFixture(
           nodePath.join(import.meta.dirname, dirPath),
           testConfig,
-        )
-        if (testConfig.afterTest) {
+        ).catch(async (err) => {
+          if (testConfig.catchError) {
+            await testConfig.catchError(err)
+            return
+          }
+          throw err
+        })
+        if (testConfig.afterTest && output) {
           await testConfig.afterTest(output)
         }
       } catch (err) {
@@ -50,8 +56,14 @@ function main() {
           const output = await compileFixture(
             nodePath.join(import.meta.dirname, dirPath),
             testConfig,
-          )
-          if (testConfig.afterTest) {
+          ).catch(async (err) => {
+            if (testConfig.catchError) {
+              await testConfig.catchError(err)
+              return
+            }
+            throw err
+          })
+          if (testConfig.afterTest && output) {
             await testConfig.afterTest(output)
           }
         } catch (err) {

packages/rolldown/tests/fixtures/builtin-plugin/wasm-fallback/_config.ts

@@ -0,0 +1,11 @@
+import { wasmFallbackPlugin } from 'rolldown/experimental'
+import { defineTest } from '@tests'
+
+export default defineTest({
+  config: {
+    plugins: [wasmFallbackPlugin()],
+  },
+  catchError: () => {
+    // Errors are swallowed here
+  },
+})

packages/rolldown/tests/fixtures/builtin-plugin/wasm-fallback/main.js

@@ -0,0 +1,5 @@
+import init from './add.wasm'
+
+init().then(({ exports }) => {
+  exports.add(1, 2) === 3
+})

packages/rolldown/tests/fixtures/builtin-plugin/wasm/_config.ts

@@ -1,8 +1,8 @@
-import { wasmPlugin } from 'rolldown/experimental'
+import { wasmFallbackPlugin, wasmPlugin } from 'rolldown/experimental'
 import { defineTest } from '@tests'
 
 export default defineTest({
   config: {
-    plugins: [wasmPlugin()],
+    plugins: [wasmPlugin(), wasmFallbackPlugin()],
   },
 })

packages/rolldown/tests/src/types.ts

@@ -6,4 +6,5 @@ export interface TestConfig {
   config?: RolldownOptions
   beforeTest?: () => Promise<void> | void
   afterTest?: (output: RolldownOutput) => Promise<void> | void
+  catchError?: (err: unknown) => Promise<void> | void
 }