feat: improve AsyncLocalStorage api (#23175)

Fixes: https://github.com/denoland/deno/issues/23174

2 files changed, 42 insertions, 0 deletions

diff --git a/ext/node/polyfills/async_hooks.ts b/ext/node/polyfills/async_hooks.ts
index d60334346..ea0bfb944 100644
--- a/ext/node/polyfills/async_hooks.ts
+++ b/ext/node/polyfills/async_hooks.ts
@@ -316,6 +316,17 @@ export class AsyncLocalStorage {
     );
     Scope.enter(frame);
   }
+
+  static bind(fn: (...args: unknown[]) => unknown) {
+    return AsyncResource.bind(fn);
+  }
+
+  static snapshot() {
+    return AsyncLocalStorage.bind((
+      cb: (...args: unknown[]) => unknown,
+      ...args: unknown[]
+    ) => cb(...args));
+  }
 }
 
 export function executionAsyncId() {
diff --git a/tests/unit_node/async_hooks_test.ts b/tests/unit_node/async_hooks_test.ts
index 076d14b54..2ed197c2d 100644
--- a/tests/unit_node/async_hooks_test.ts
+++ b/tests/unit_node/async_hooks_test.ts
@@ -94,3 +94,34 @@ Deno.test(async function enterWith() {
   assertEquals(await deferred.promise, { x: 2 });
   assertEquals(await deferred1.promise, { x: 1 });
 });
+
+Deno.test(async function snapshot() {
+  const als = new AsyncLocalStorage();
+  const deferred = Promise.withResolvers();
+
+  als.run(null, () => {
+    const snapshot = AsyncLocalStorage.snapshot();
+    als.run({ x: 1 }, () => {
+      deferred.resolve(snapshot(() => als.getStore()));
+    });
+  });
+
+  assertEquals(await deferred.promise, null);
+});
+
+Deno.test(async function bind() {
+  const als = new AsyncLocalStorage();
+  const deferred = Promise.withResolvers();
+
+  const bound = als.run(null, () => {
+    return AsyncLocalStorage.bind(() => {
+      deferred.resolve(als.getStore());
+    });
+  });
+
+  als.run({ x: 1 }, () => {
+    bound();
+  });
+
+  assertEquals(await deferred.promise, null);
+});