Add changeset

.changeset/olive-worms-run.md

@@ -10,13 +10,17 @@ Before:
 
 ```typescript
 import createLogger from '@seek/logger';
-import Koa from 'koa';
+import Koa, { Context } from 'koa';
 import { RequestLogging } from 'seek-koala';
+
 const rootLogger = createLogger();
+
 const contextLogger = (ctx: Context) =>
   rootLogger.child(RequestLogging.contextFields(ctx));
+
 const app = new Koa().use((ctx) => {
   rootLogger.info('Has no context');
+
   contextLogger(ctx).info('Has context');
 });
 ```
@@ -27,10 +31,14 @@ After:
 import createLogger from '@seek/logger';
 import Koa from 'koa';
 import { RequestLogging } from 'seek-koala';
+
 const { createContextMiddleware, mixin } =
   RequestLogging.createContextStorage();
+
 const contextMiddleware = createContextMiddleware();
+
 const logger = createLogger({ mixin });
+
 const app = new Koa().use(contextMiddleware).use((ctx) => {
   logger.info('Has context');
 });

.changeset/pink-flowers-vanish.md

@@ -0,0 +1,45 @@
+---
+'skuba': patch
+---
+
+template/lambda-sqs-worker: Use [AsyncLocalStorage](https://nodejs.org/docs/latest-v16.x/api/async_context.html#asynchronous-context-tracking) to track logger context
+
+We now employ this Node.js API to thread logging context through the handler of your Lambda function. This enables use of a singleton `logger` instance instead of manually propagating Lambda context and juggling `rootLogger`s and `contextLogger`s, and is equivalent to #864.
+
+Before:
+
+```typescript
+import createLogger from '@seek/logger';
+import { Context } from 'aws-lambda';
+
+const rootLogger = createLogger();
+
+const contextLogger = ({ awsRequestId }: Context) =>
+  rootLogger.child({ awsRequestId });
+
+const handler = async (_event: unknown, ctx: Context) => {
+  rootLogger.info('Has no context');
+
+  contextLogger(ctx).info('Has context');
+};
+```
+
+After:
+
+```typescript
+import { AsyncLocalStorage } from 'async_hooks';
+
+import createLogger from '@seek/logger';
+import { Context } from 'aws-lambda';
+
+const loggerContext = new AsyncLocalStorage<{ awsRequestId: string }>();
+
+const logger = createLogger({
+  mixin: () => loggerContext.getStore() ?? {},
+});
+
+const handler = (_event: unknown, { awsRequestId }: Context) =>
+  loggerContext.run({ awsRequestId }, async () => {
+    logger.info('Has context');
+  });
+```