refactor: split runtime logic

Author: pi0

src/plugin/index.ts

@@ -4,6 +4,8 @@ import MagicString from "magic-string";
 import type { RenderedChunk, Plugin as RollupPlugin } from "rollup";
 import { createUnplugin } from "unplugin";
 import { parseWasm } from "../tools";
+import { getWasmESMBinding, getWasmModuleBinding } from "./runtime/binding";
+import { getPluginUtils } from "./runtime/utils";
 import {
   sha1,
   UMWASM_HELPERS_ID,
@@ -12,11 +14,6 @@ import {
   UnwasmPluginOptions,
   WasmAsset,
 } from "./shared";
-import {
-  getPluginUtils,
-  getWasmESMBinding,
-  getWasmModuleBinding,
-} from "./runtime";
 
 export type { UnwasmPluginOptions } from "./shared";
 

src/plugin/runtime.ts

@@ -0,0 +1,94 @@
+import {
+  UMWASM_HELPERS_ID,
+  UNWASM_EXTERNAL_PREFIX,
+  WasmAsset,
+  UnwasmPluginOptions,
+} from "../shared";
+import { getWasmImports } from "./imports";
+
+/**
+ * Returns ESM compatible exports binding
+ */
+export async function getWasmESMBinding(
+  asset: WasmAsset,
+  opts: UnwasmPluginOptions,
+) {
+  // -- Auto load imports --
+  const autoImports = await getWasmImports(asset, opts);
+
+  // --- Environment dependent code to initialize the wasm module using inlined base64 or dynamic import ---
+  const envCode: string = opts.esmImport
+    ? /* js */ `
+${autoImports.code};
+
+async function _instantiate(imports = _imports) {
+  const _mod = await import("${UNWASM_EXTERNAL_PREFIX}${asset.name}").then(r => r.default || r);
+  return WebAssembly.instantiate(_mod, imports)
+}
+  `
+    : /* js */ `
+import { base64ToUint8Array } from "${UMWASM_HELPERS_ID}";
+${autoImports.code};
+
+function _instantiate(imports = _imports) {
+  const _data = base64ToUint8Array("${asset.source.toString("base64")}")
+  return WebAssembly.instantiate(_data, imports)
+}
+  `;
+
+  // --- Binding code to export the wasm module exports ---
+  const canTopAwait = opts.lazy !== true && autoImports.resolved;
+
+  // eslint-disable-next-line unicorn/prefer-ternary
+  if (canTopAwait) {
+    // -- Non proxied exports when no imports are needed and we can have top-level await ---
+    return /* js */ `
+import { getExports } from "${UMWASM_HELPERS_ID}";
+${envCode}
+
+const $exports = getExports(await _instantiate());
+
+${asset.exports
+  .map((name) => `export const ${name} = $exports.${name};`)
+  .join("\n")}
+
+const defaultExport = () => $exports;
+${asset.exports.map((name) => `defaultExport["${name}"] = $exports.${name};`).join("\n")}
+export default defaultExport;
+    `;
+  } else {
+    // --- Proxied exports when imports are needed or we can't have top-level await ---
+    return /* js */ `
+import { createLazyWasmModule } from "${UMWASM_HELPERS_ID}";
+${envCode}
+
+const _mod = createLazyWasmModule(_instantiate);
+
+${asset.exports
+  .map((name) => `export const ${name} = _mod.${name};`)
+  .join("\n")}
+
+export default _mod;
+    `;
+  }
+}
+
+/**
+ * Returns WebAssembly.Module binding for compatibility
+ */
+export function getWasmModuleBinding(
+  asset: WasmAsset,
+  opts: UnwasmPluginOptions,
+) {
+  return opts.esmImport
+    ? /* js */ `
+const _mod = ${opts.lazy === true ? "" : `await`} import("${UNWASM_EXTERNAL_PREFIX}${asset.name}").then(r => r.default || r);
+export default _mod;
+  `
+    : /* js */ `
+import { base64ToUint8Array } from "${UMWASM_HELPERS_ID}";
+const _data = base64ToUint8Array("${asset.source.toString("base64")}");
+const _mod = new WebAssembly.Module(_data);
+export default _mod;
+  `;
+}