sync

1 files changed, 25 insertions, 0 deletions

diff --git a/js/src/util/context.ts b/js/src/util/context.ts
new file mode 100644
index 000000000..ec686293e
--- /dev/null
+++ b/js/src/util/context.ts
@@ -0,0 +1,25 @@
+import { AsyncLocalStorage } from "node:async_hooks";
+
+export namespace Context {
+  export class NotFound extends Error {
+    constructor(public readonly name: string) {
+      super(`No context found for ${name}`);
+    }
+  }
+
+  export function create<T>(name: string) {
+    const storage = new AsyncLocalStorage<T>();
+    return {
+      use() {
+        const result = storage.getStore();
+        if (!result) {
+          throw new NotFound(name);
+        }
+        return result;
+      },
+      provide<R>(value: T, fn: () => R) {
+        return storage.run<R>(value, fn);
+      },
+    };
+  }
+}