Convert project to TypeScript

Remove `SharpLayer` variable from all templates and documentation
Use @types/aws-lambda where possible

Author: mbklein

.eslintrc

@@ -4,11 +4,11 @@
 deploy.yml
 deploy.yaml
 node_modules
-samconfig.toml
+samconfig.*
+!sam/samconfig.example.yaml
 env.json
 package.yml
 package.yaml
-samconfig.*
 
 # NodeJS Build
 coverage

.gitignore

@@ -0,0 +1,35 @@
+# Repository Guidelines
+
+## Project Structure & Module Organization
+- `src/`: Lambda handler (`index.js`), helpers, resolvers, error handling, streaming.
+- `tests/`: Jest tests (`*.test.js`) and mocks.
+- `sam/`: AWS SAM templates.
+- `docs/`: Next.js site for documentation.
+- `scripts/`, `bin/`, `examples/`, `Dockerfile`, `Makefile`: tooling and examples.
+
+## Build, Test, and Development Commands
+- `npm test`: run Jest (watch locally; single run on CI).
+- `npm run test-coverage`: Jest with coverage.
+- `npm run lint` / `npm run lint-fix`: ESLint check/fix for `src/*.js`.
+- `npm run build`: `sam build -t sam/template.yml --use-container`.
+- `npm run deploy` / `npm run deploy-guided`: deploy via SAM using `deploy.yml`.
+- Make targets (advanced): `make aws-package`, `make aws-publish` (requires Docker and `AWS_PROFILE`).
+
+## Coding Style & Naming Conventions
+- JavaScript with 2‑space indentation, LF line endings, final newline (`.editorconfig`).
+- ESLint (Standard config). Key rules: semicolons required, object spacing, `prefer-const`, max lines per function warning.
+- Files in `src/` are small, single‑purpose modules. Tests live in `tests/` and end with `.test.js` (e.g., `helpers.test.js`).
+
+## Testing Guidelines
+- Framework: Jest; coverage from `src/**/*.js`; Node test environment.
+- Name tests descriptively (e.g., `index.v2.test.js`, `resolvers.test.js`).
+- Run: `npm test` (watch) or `npm test -- --runInBand` for CI‑like runs. Keep PRs from decreasing coverage.
+
+## Commit & Pull Request Guidelines
+- Branch from `main` (do not create `master`). Keep changes focused.
+- Commits: present‑tense summary + wrapped body; reference issues (e.g., “Closes #123”).
+- PRs must include: clear description, linked issues, tests, passing CI (CircleCI), and clean lint. Add screenshots for docs/UI changes when relevant.
+
+## Security & Configuration Tips
+- Core env vars: `tiffBucket`, `resolverTemplate`, `preflight`, `corsAllow*`, `forceHost`, `pyramidLimit`, `pageThreshold`, `density`, `debugBorder`.
+- S3 access uses AWS SDK v3; grant least‑privilege IAM to the source bucket.

AGENTS.md

@@ -86,27 +86,42 @@ be considered for inclusion in the code base and history of this repository.
 #### Prerequisites
 
 - Some basic knowledge of AWS and [CloudFormation](https://aws.amazon.com/cloudformation/)
-- Requires the [SAM CLI](https://aws.amazon.com/serverless/sam/) and [AWS CLI](https://aws.amazon.com/cli/)
-- Building dependencies with the correct architecture on non-Linux systems requires [Docker](https://docs.docker.com/get-docker/).
+- [AWS CLI](https://aws.amazon.com/cli/)
+- [SAM CLI](https://aws.amazon.com/serverless/sam/)
+- [Docker](https://docs.docker.com/get-docker/)
+- The [make](https://www.gnu.org/software/make/) build tool (included with build tools on most UNIX-like operating systems)
 
-#### Deploy
+#### Building and Deploying
 
-The following instructions require you to `cd` into the correct directory for whichever flavor of the template you're using - `sam/standalone` for the Lambda-only version, or `sam/cloudfront` for the CloudFront-enabled version.
+The first time you run any of the build/package/publish/deploy commands, the `libvips`/`sharp` dependency layer will 
+be built from source, which may take a while. But as long as you don't clear the Docker build cache (via 
+`docker builder prune` or `docker system prune`), future calls should be nice and fast.
 
-For iterative development, you may want to use [SAM Accelerate](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/accelerate.html) to keep the deployed stack in sync with local changes automatically.
+The file `sam/samconfig.example.yaml` contains examples of both `deploy` and `sync` configurations for command-line
+deployment and iterative development. Copy it to `sam/samconfig.yaml` and modify it to suit your configuration before
+running the commands below.
 
-##### Using SAM
+##### Deploying
 
-The easiest way to deploy is using the SAM guided command:
+```sh
+make deploy
+```
+
+If you haven't created a [SAM configuration file](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-config.html) per the above instructions, you will be guided through a series of prompts to provide the correct values, and then prompted to save the configuration file at the end before the stack is deployed.
+
+If the stack deploys successfully, make note of the `Endpoint - IIIF Endpoint URL` output. You'll need this to test the API.
+
+##### Iterative Development
 
 ```sh
-sam build --use-container
-sam deploy --guided
+make dev
 ```
 
-If successful, make note of the `Endpoint - IIIF Endpoint URL` output. You'll need this to test the API.
+This command deploys a stack and then watches the source for changes, which are synced automatically to the stack
+without all the CloudFormation overhead until you quit the watch process. This command does not have a guided
+deployment option, so it relies on the `default.sync` section of the SAM configuration file.
 
-#### Test the API
+##### Testing the API
 
 To test the API, you'll need an identifier that exists in your source bucket. Make a request for that identifier with:
 

CONTRIBUTING.md

@@ -10,11 +10,10 @@ Previous versions of this application featured an optional [CloudFront](https://
 
 While the CloudFront-enabled version of the application will remain available for the in the Serverless Application Repository for a time to provide an easy upgrade path for existing users, it is _strongly_ recommended that new deployments use the provided [documentation](https://samvera.github.io/serverless-iiif/docs/quick-start/infrastructure) and [examples](./examples) of [CloudFormation](https://aws.amazon.com/cloudformation/) templates and [Terraform](https://terraform.io/) manifests to deploy the standalone function as part of a larger application/infrastructure stack that defines its own CloudFront distribution.
 
-### Breaking Changes from Version 4.x
+### Breaking Changes from Version 5.x
 
-- The value of the `SharpLayer` variable must now be one of `INTERNAL`, `JP2`, or a valid Lambda layer ARN in the same region the 
-  application is being deployed in. The new default is `JP2`, which behaves the same as the former default (empty string). The new
-  value, `INTERNAL`, uses the `sharp` and `libvips` dependencies compiled into the application itself.
+- The `SharpLayer` variable has been removed, and the `sharp` dependency (with JP2 support) bundled into the published
+  package.
 
 ## Description
 

README.md

@@ -20,6 +20,5 @@ default:
         PixelDensity="0"
         Preflight="false"
         ResolverTemplate="%s.tif"
-        SharpLayer=""
         SourceBucket=""
       image_repositories: []

deploy.yml.example

@@ -0,0 +1,106 @@
+import { defineConfig, globalIgnores } from "eslint/config";
+import typescriptEslint from "@typescript-eslint/eslint-plugin";
+import globals from "globals";
+import tsParser from "@typescript-eslint/parser";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import js from "@eslint/js";
+import { FlatCompat } from "@eslint/eslintrc";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+    baseDirectory: __dirname,
+    recommendedConfig: js.configs.recommended,
+    allConfig: js.configs.all
+});
+
+export default defineConfig([
+  globalIgnores([
+    "coverage/**/*",
+    "docs/**/*",
+    "node_modules/**/*",
+    "build/**/*",
+  ]),
+  {
+    extends: compat.extends("plugin:@typescript-eslint/recommended"),
+
+    plugins: {
+      "@typescript-eslint": typescriptEslint,
+    },
+
+    languageOptions: {
+      globals: {
+        ...Object.fromEntries(
+          Object.entries(globals.browser).map(([key]) => [key, "off"])
+        ),
+        ...globals.node,
+        ...globals.jest,
+        __DEV__: false,
+        __TEST__: false,
+        __PROD__: false,
+        __COVERAGE__: false,
+      },
+
+      parser: tsParser,
+    },
+
+    rules: {
+      "brace-style": [2, "1tbs"],
+      "comma-dangle": [2, "never"],
+
+      indent: [
+        "error",
+        2,
+        {
+          SwitchCase: 1,
+        },
+      ],
+
+      "key-spacing": 0,
+      "max-len": [0, 120, 2],
+
+      "max-lines-per-function": [
+        "warn",
+        {
+          max: 30,
+          skipBlankLines: true,
+          skipComments: true,
+        },
+      ],
+
+      "no-unused-vars": [
+        1,
+        {
+          vars: "all",
+          args: "after-used",
+          ignoreRestSiblings: false,
+          argsIgnorePattern: "^_",
+        },
+      ],
+
+      "no-var": 1,
+      "object-curly-spacing": [2, "always"],
+
+      "prefer-const": [
+        1,
+        {
+          destructuring: "any",
+          ignoreReadBeforeAssign: true,
+        },
+      ],
+
+      semi: [2, "always"],
+      "space-in-parens": ["error", "never"],
+      complexity: ["warn", 6],
+      "@typescript-eslint/no-explicit-any": "warn",
+    },
+  },
+  {
+    files: ["tests/**/*.{ts,tsx}"],
+    rules: {
+      "max-lines-per-function": "off",
+      complexity: "off",
+    },
+  },
+]);

eslint.config.mjs

@@ -30,7 +30,6 @@ resource "aws_serverlessapplicationrepository_cloudformation_stack" "serverless_
     PixelDensity            = var.pixel_density
     Preflight               = var.preflight
     ResolverTemplate        = var.resolver_template
-    SharpLayer              = var.sharp_layer
     SourceBucket            = var.source_bucket
   }
 }

extras/terraform/main.tf

@@ -1,10 +1,15 @@
 module.exports = {
-  collectCoverageFrom: ['src/**/*.js'],
+  preset: 'ts-jest',
+  transform: {
+    '^.+\\.(ts|tsx)$': 'ts-jest',
+  },
+  collectCoverageFrom: ['src/**/*.ts'],
   testPathIgnorePatterns: [
     '<rootDir>[/\\\\](build|docs|node_modules|scripts)[/\\\\]',
   ],
   testEnvironment: 'node',
   moduleDirectories: ['node_modules'],
+  moduleFileExtensions: ['ts', 'js', 'json'],
   moduleNameMapper: {
     '^uuid$': require.resolve('uuid'),
   },