2 files changed, 52 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 ${name}`);
+    }
+  }
+
+  export function create<T>(name: string) {
+    const storage = new AsyncLocalStorage<T>();
+    return {
+      use() {
+        const result = storage.getStore();
+        if (!result) {
+          throw new NotFound(name);
+        }
+        return result;
+      },
+      provide<R>(value: T, fn: () => R) {
+        return storage.run<R>(value, fn);
+      },
+    };
+  }
+}
diff --git a/js/src/util/log.ts b/js/src/util/log.ts
new file mode 100644
index 000000000..9de4eb495
--- /dev/null
+++ b/js/src/util/log.ts
@@ -0,0 +1,27 @@
+export namespace Log {
+  export function create(tags?: Record<string, any>) {
+    tags = tags || {};
+
+    const result = {
+      info(message?: any, extra?: Record<string, any>) {
+        const prefix = Object.entries({
+          ...tags,
+          ...extra,
+        })
+          .map(([key, value]) => `${key}=${value}`)
+          .join(" ");
+        console.log(prefix, message);
+        return result;
+      },
+      tag(key: string, value: string) {
+        if (tags) tags[key] = value;
+        return result;
+      },
+      clone() {
+        return Log.create({ ...tags });
+      },
+    };
+
+    return result;
+  }
+}