feat: streaming lambda handler (#167)

* feat: add prototype implementation

* chore: fix eslint config

* fix: use NodeStream to convert

* refactor: more effectful implementation

* fix: do not wait for empty event loop when using global layer

* chore: add proper dependencies and fix docgen

Author: floydspace

.changeset/lemon-cows-smoke.md

@@ -0,0 +1,53 @@
+---
+"@effect-aws/lambda": minor
+---
+
+Implement streaming lambda handler
+
+### Usage
+
+```ts
+import { LambdaHandler, StreamHandler } from "@effect-aws/lambda"
+import { NodeStream } from "@effect/platform-node"
+import type { LambdaFunctionURLEvent } from "aws-lambda"
+import { Cause, Stream } from "effect"
+import { createGzip } from "node:zlib"
+
+/**
+ * Streaming handler that takes a Lambda Function URL event, compresses it using gzip and
+ * returns the compressed data as a stream.
+ */
+const streamHandler: StreamHandler<
+  LambdaFunctionURLEvent,
+  never,
+  Cause.UnknownException
+> = (event) => {
+  return Stream.make(Buffer.from(JSON.stringify(event))).pipe(
+    Stream.pipeThroughChannelOrFail(
+      NodeStream.fromDuplex(
+        () => createGzip(),
+        (e) => new Cause.UnknownException(e)
+      )
+    )
+  )
+}
+
+export const handler = LambdaHandler.stream(streamHandler)
+```
+
+Set the lambda function URL `InvokeMode` to `RESPONSE_STREAM`:
+
+```yaml
+MyFunctionUrl:
+  Type: AWS::Lambda::Url
+  Properties:
+    TargetFunctionArn: !Ref StreamingFunction
+    AuthType: AWS_IAM
+    InvokeMode: RESPONSE_STREAM
+```
+
+deploy the stack, and then invoke the function URL:
+
+```bash
+curl --request GET https://<url>.lambda-url.<Region>.on.aws/ --user $AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY --aws-sigv4 'aws:amz:<Region>:lambda' --output response.gz
+```

.projen/deps.json

@@ -42,11 +42,11 @@ new Vitest(project, { sharedSetupFiles: ["vitest.setup.ts"] });
 project.addDevDeps("vitest-mock-extended");
 project.addDevDeps("aws-sdk-client-mock", "aws-sdk-client-mock-vitest");
 
-const effectDeps = ["effect@3.14.11"];
+const effectDeps = ["effect"];
 
 project.addScripts({ "codegen-client": "tsx ./scripts/codegen-cli.ts" });
-project.addDeps(...effectDeps, "@effect/cli@0.59.11", "@effect/platform@0.80.11", "@effect/platform-node@0.76.21");
-project.addDevDeps("@effect/language-service", "@effect/vitest@0.20.11");
+project.addDeps(...effectDeps, "@effect/cli", "@effect/platform", "@effect/platform-node");
+project.addDevDeps("@effect/language-service", "@effect/vitest");
 project.tsconfigBase?.file.addOverride("compilerOptions.plugins", [
   { name: "@effect/language-service" },
 ]);
@@ -106,8 +106,8 @@ const lambda = new TypeScriptLibProject({
   parent: project,
   name: "lambda",
   description: "Effectful AWS Lambda handler",
-  devDeps: [...effectDeps, "@types/aws-lambda"],
-  peerDeps: commonPeerDeps,
+  devDeps: [...effectDeps, "@effect/platform", "@effect/platform-node-shared", "@types/aws-lambda"],
+  peerDeps: [...commonPeerDeps, "@effect/platform@>=0.69.25", "@effect/platform-node-shared@>=0.19.26"],
   addExamples: true,
 });
 
@@ -162,7 +162,7 @@ new TypeScriptLibProject({
   parent: project,
   name: "s3",
   description: "Effectful AWS S3 functions",
-  devDeps: [...effectDeps, "@effect/platform@0.80.11", "@aws-sdk/client-s3@^3"],
+  devDeps: [...effectDeps, "@effect/platform", "@aws-sdk/client-s3@^3"],
   peerDeps: [...commonPeerDeps, "@effect/platform@>=0.69.25"],
   workspacePeerDeps: [s3Client],
   addExamples: true,
@@ -173,7 +173,7 @@ new TypeScriptLibProject({
   name: "http-handler",
   description: "Effectful AWS HTTP handler",
   deps: ["@smithy/types", "@smithy/protocol-http", "@smithy/querystring-builder"],
-  devDeps: [...effectDeps, "@effect/platform@0.80.11"],
+  devDeps: [...effectDeps, "@effect/platform"],
   peerDeps: [...commonPeerDeps, "@effect/platform@>=0.69.25"],
   workspacePeerDeps: [commons],
 });

.projenrc.ts

@@ -1,3 +1,4 @@
+import * as effectEslint from "@effect/eslint-plugin";
 import { fixupPluginRules } from "@eslint/compat";
 import { FlatCompat } from "@eslint/eslintrc";
 import js from "@eslint/js";
@@ -25,8 +26,8 @@ export default [
     "eslint:recommended",
     "plugin:@typescript-eslint/eslint-recommended",
     "plugin:@typescript-eslint/recommended",
-    "plugin:@effect/recommended",
   ),
+  ...effectEslint.configs.dprint,
   {
     plugins: {
       import: fixupPluginRules(_import),