fix: cache wasm file locally after first run (#313)

deno.jsonc

@@ -2,43 +2,33 @@
   "lock": false,
   "tasks": {
     "test": "deno test -A",
-    "build": "deno run -A --no-check --unstable https://deno.land/x/wasmbuild@0.10.4/main.ts --out lib/pkg"
-  },
-  "test": {
-    "exclude": [
-      "./tests/declaration_import_project/npm",
-      "./tests/import_map_project/npm",
-      "./tests/json_module_project/npm",
-      "./tests/module_mappings_project/npm",
-      "./tests/node_types_project/npm",
-      "./tests/package_mappings_project/npm",
-      "./tests/polyfill_array_find_last_project/npm",
-      "./tests/polyfill_project/npm",
-      "./tests/shim_project/npm",
-      "./tests/test_project/npm",
-      "./tests/tla_project/npm",
-      "./tests/undici_project/npm",
-      "./tests/web_socket_project/npm"
-    ]
-  },
-  "fmt": {
-    "exclude": [
-      "target/",
-      "wasm/target/"
-    ]
+    "build": "deno run -A --no-check --unstable https://deno.land/x/wasmbuild@0.13.0/main.ts --out lib/pkg"
   },
   "lint": {
     "rules": {
       "exclude": [
         "no-explicit-any",
         "camelcase"
       ]
-    },
-    "exclude": [
-      "target/",
-      "wasm/target/",
-      "lib/pkg/",
-      "rs-lib/src/polyfills/scripts/"
-    ]
-  }
+    }
+  },
+  "exclude": [
+    "target/",
+    "wasm/target/",
+    "lib/pkg/",
+    "rs-lib/src/polyfills/scripts/",
+    "tests/declaration_import_project/npm",
+    "tests/import_map_project/npm",
+    "tests/json_module_project/npm",
+    "tests/module_mappings_project/npm",
+    "tests/node_types_project/npm",
+    "tests/package_mappings_project/npm",
+    "tests/polyfill_array_find_last_project/npm",
+    "tests/polyfill_project/npm",
+    "tests/shim_project/npm",
+    "tests/test_project/npm",
+    "tests/tla_project/npm",
+    "tests/undici_project/npm",
+    "tests/web_socket_project/npm"
+  ]
 }

lib/pkg/dnt_wasm.generated.js

@@ -529,6 +529,13 @@ const imports = {
   },
 };
 
+import { Loader } from "https://deno.land/x/wasmbuild@0.13.0/loader.ts";
+import { cacheToLocalDir } from "https://deno.land/x/wasmbuild@0.13.0/cache.ts";
+
+const loader = new Loader({
+  imports,
+  cache: cacheToLocalDir,
+});
 /**
  * Decompression callback
  *
@@ -554,9 +561,6 @@ export async function instantiate(opts) {
   return (await instantiateWithInstance(opts)).exports;
 }
 
-let instanceWithExports;
-let lastLoadPromise;
-
 /** Instantiates an instance of the Wasm module along with its exports.
  * @remarks It is safe to call this multiple times and once successfully
  * loaded it will always return a reference to the same object.
@@ -566,28 +570,18 @@ let lastLoadPromise;
  *   exports: { transform: typeof transform }
  * }>}
  */
-export function instantiateWithInstance(opts) {
-  if (instanceWithExports != null) {
-    return Promise.resolve(instanceWithExports);
-  }
-  if (lastLoadPromise == null) {
-    lastLoadPromise = (async () => {
-      try {
-        const instance = (await instantiateModule(opts ?? {})).instance;
-        wasm = instance.exports;
-        cachedInt32Memory0 = new Int32Array(wasm.memory.buffer);
-        cachedUint8Memory0 = new Uint8Array(wasm.memory.buffer);
-        instanceWithExports = {
-          instance,
-          exports: getWasmInstanceExports(),
-        };
-        return instanceWithExports;
-      } finally {
-        lastLoadPromise = null;
-      }
-    })();
-  }
-  return lastLoadPromise;
+export async function instantiateWithInstance(opts) {
+  const { instance } = await loader.load(
+    opts?.url ?? new URL("dnt_wasm_bg.wasm", import.meta.url),
+    opts?.decompress,
+  );
+  wasm = wasm ?? instance.exports;
+  cachedInt32Memory0 = cachedInt32Memory0 ?? new Int32Array(wasm.memory.buffer);
+  cachedUint8Memory0 = cachedUint8Memory0 ?? new Uint8Array(wasm.memory.buffer);
+  return {
+    instance,
+    exports: getWasmInstanceExports(),
+  };
 }
 
 function getWasmInstanceExports() {
@@ -596,61 +590,5 @@ function getWasmInstanceExports() {
 
 /** Gets if the Wasm module has been instantiated. */
 export function isInstantiated() {
-  return instanceWithExports != null;
-}
-
-/**
- * @param {InstantiateOptions} opts
- */
-async function instantiateModule(opts) {
-  const wasmUrl = opts.url ?? new URL("dnt_wasm_bg.wasm", import.meta.url);
-  const decompress = opts.decompress;
-  const isFile = wasmUrl.protocol === "file:";
-
-  // make file urls work in Node via dnt
-  const isNode = globalThis.process?.versions?.node != null;
-  if (isNode && isFile) {
-    // the deno global will be shimmed by dnt
-    const wasmCode = await Deno.readFile(wasmUrl);
-    return WebAssembly.instantiate(
-      decompress ? decompress(wasmCode) : wasmCode,
-      imports,
-    );
-  }
-
-  switch (wasmUrl.protocol) {
-    case "file:":
-    case "https:":
-    case "http:": {
-      if (isFile) {
-        if (typeof Deno !== "object") {
-          throw new Error("file urls are not supported in this environment");
-        }
-        if ("permissions" in Deno) {
-          await Deno.permissions.request({ name: "read", path: wasmUrl });
-        }
-      } else if (typeof Deno === "object" && "permissions" in Deno) {
-        await Deno.permissions.request({ name: "net", host: wasmUrl.host });
-      }
-      const wasmResponse = await fetch(wasmUrl);
-      if (decompress) {
-        const wasmCode = new Uint8Array(await wasmResponse.arrayBuffer());
-        return WebAssembly.instantiate(decompress(wasmCode), imports);
-      }
-      if (
-        isFile ||
-        wasmResponse.headers.get("content-type")?.toLowerCase()
-          .startsWith("application/wasm")
-      ) {
-        return WebAssembly.instantiateStreaming(wasmResponse, imports);
-      } else {
-        return WebAssembly.instantiate(
-          await wasmResponse.arrayBuffer(),
-          imports,
-        );
-      }
-    }
-    default:
-      throw new Error(`Unsupported protocol: ${wasmUrl.protocol}`);
-  }
+  return loader.instance != null;
 }