feat: Allow embedded PDPs to be loaded from precompiled WebAssembly.Modules

docs/embedded.loader._constructor_.md

@@ -88,3 +88,13 @@ import { readFile } from "fs/promises";
 const loader = new Loader(readFile("policies.wasm"));
 ```
 
+## Example 3
+
+Load an embedded PDP bundle from a precompiled WebAssembly module (requires a bundler):
+
+```typescript
+import bundle from "bundle.wasm";
+
+const loader = new Loader(bundle);
+```
+

docs/embedded.source.md

@@ -9,5 +9,5 @@ WebAssembly binary code of an embedded policy decision point bundle, or a URL or
 **Signature:**
 
 ```typescript
-export type Source = string | URL | ArrayBufferView | ArrayBuffer | Response | Promise<ArrayBufferView | ArrayBuffer | Response>;
+export type Source = string | URL | ArrayBufferView | ArrayBuffer | Response | WebAssembly.Module | Promise<ArrayBufferView | ArrayBuffer | Response | WebAssembly.Module>;
 ```

packages/embedded/CHANGELOG.md

@@ -2,7 +2,9 @@
 
 ## [Unreleased]
 
-No notable changes.
+### Added
+
+- Support for loading a precompiled `WebAssembly.Module` ([#1016](https://github.com/cerbos/cerbos-sdk-javascript/pull/1016))
 
 ## [0.7.3] - 2024-06-11
 

packages/embedded/changelog.yaml

@@ -1,3 +1,10 @@
+unreleased:
+  type: minor
+
+  added:
+    - summary: Support for loading a precompiled `WebAssembly.Module`
+      pull: 1016
+
 releases:
   - version: 0.7.3
     date: 2024-06-11

packages/embedded/src/bundle.ts

@@ -156,7 +156,7 @@ export async function download(
 }
 
 async function instantiate(
-  source: ArrayBufferView | ArrayBuffer | Response,
+  source: ArrayBufferView | ArrayBuffer | Response | WebAssembly.Module,
   imports: WebAssembly.Imports,
 ): Promise<Exports> {
   if (source instanceof Response) {
@@ -182,8 +182,11 @@ async function instantiateStreaming(
   );
 }
 
-function instantiated({
-  instance: { exports },
-}: WebAssembly.WebAssemblyInstantiatedSource): Exports {
+function instantiated(
+  result: WebAssembly.Instance | WebAssembly.WebAssemblyInstantiatedSource,
+): Exports {
+  const { exports } =
+    result instanceof WebAssembly.Instance ? result : result.instance;
+
   return exports as Exports;
 }

packages/embedded/src/loader.ts

@@ -61,7 +61,8 @@ export type Source =
   | ArrayBufferView
   | ArrayBuffer
   | Response
-  | Promise<ArrayBufferView | ArrayBuffer | Response>;
+  | WebAssembly.Module
+  | Promise<ArrayBufferView | ArrayBuffer | Response | WebAssembly.Module>;
 
 /**
  * Options for creating a new {@link Embedded} client or {@link Loader}.
@@ -232,6 +233,15 @@ export class Loader {
    *
    * const loader = new Loader(readFile("policies.wasm"));
    * ```
+   *
+   * @example
+   * Load an embedded PDP bundle from a precompiled WebAssembly module (requires a bundler):
+   *
+   * ```typescript
+   * import bundle from "bundle.wasm";
+   *
+   * const loader = new Loader(bundle);
+   * ```
    */
   public constructor(
     source: Source,

private/test/src/matrix-node/embedded/loader.test.ts

@@ -89,6 +89,16 @@ describe("loaders", () => {
         "Promise<Response>",
         async (): Promise<Response> => await fetch(server.url),
       ],
+      [
+        "WebAssembly.Module",
+        (): WebAssembly.Module =>
+          new WebAssembly.Module(readFileSync(bundleFilePath(first))),
+      ],
+      [
+        "Promise<WebAssembly.Module>",
+        async (): Promise<WebAssembly.Module> =>
+          await WebAssembly.compile(await readFile(bundleFilePath(first))),
+      ],
     ])("%s", async (_, source) => {
       const callbacks = new Callbacks();
       const loader = new Loader(source(), callbacks);