fix: restored the compact layer (#126)

* fix: restored the compact layer

* fix: linter issue

Author: ematipico

src/compatLayer.js

@@ -0,0 +1,122 @@
+// @ts-nocheck
+/**
+ * Credits to https://github.com/danielcondemarin
+ * https://github.com/danielcondemarin/serverless-nextjs-plugin/blob/master/packages/next-aws-lambda/lib/compatLayer.js
+ */
+const Stream = require("stream");
+const queryString = require("querystring");
+
+const requestResponseMapper = (event, callback) => {
+	const base64Support = process.env.BINARY_SUPPORT === "yes";
+	const response = {
+		body: Buffer.from(""),
+		isBase64Encoded: base64Support,
+		statusCode: 200,
+		multiValueHeaders: {}
+	};
+
+	const request = new Stream.Readable();
+	request.url = (event.requestContext.path || event.path || "").replace(new RegExp("^/" + event.requestContext.stage), "");
+
+	let qs = "";
+
+	if (event.multiValueQueryStringParameters) {
+		qs += queryString.stringify(event.multiValueQueryStringParameters);
+	}
+
+	if (event.pathParameters) {
+		const pathParametersQs = queryString.stringify(event.pathParameters);
+
+		if (qs.length > 0) {
+			qs += `&${pathParametersQs}`;
+		} else {
+			qs += pathParametersQs;
+		}
+	}
+
+	const hasQueryString = qs.length > 0;
+
+	if (hasQueryString) {
+		request.url += `?${qs}`;
+	}
+
+	request.method = event.httpMethod;
+	request.rawHeaders = [];
+	request.headers = {};
+
+	const headers = event.multiValueHeaders || {};
+
+	for (const key of Object.keys(headers)) {
+		for (const value of headers[key]) {
+			request.rawHeaders.push(key);
+			request.rawHeaders.push(value);
+		}
+		request.headers[key.toLowerCase()] = headers[key].toString();
+	}
+
+	request.getHeader = name => {
+		return request.headers[name.toLowerCase()];
+	};
+	request.getHeaders = () => {
+		return request.headers;
+	};
+
+	request.connection = {};
+
+	// eslint-disable-next-line unicorn/prevent-abbreviations
+	const res = new Stream();
+	Object.defineProperty(res, "statusCode", {
+		get() {
+			return response.statusCode;
+		},
+		set(statusCode) {
+			response.statusCode = statusCode;
+		}
+	});
+	res.headers = {};
+	res.writeHead = (status, headers) => {
+		response.statusCode = status;
+		if (headers) res.headers = Object.assign(res.headers, headers);
+	};
+	res.write = chunk => {
+		response.body = Buffer.concat([response.body, Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk)]);
+	};
+	res.setHeader = (name, value) => {
+		res.headers[name] = value;
+	};
+	res.removeHeader = name => {
+		delete res.headers[name];
+	};
+	res.getHeader = name => {
+		return res.headers[name.toLowerCase()];
+	};
+	res.getHeaders = () => {
+		return res.headers;
+	};
+	res.end = text => {
+		if (text) res.write(text);
+		response.body = Buffer.from(response.body).toString(base64Support ? "base64" : undefined);
+		response.multiValueHeaders = res.headers;
+		res.writeHead(response.statusCode);
+		fixApiGatewayMultipleHeaders();
+		callback(null, response);
+	};
+	if (event.body) {
+		request.push(event.body, event.isBase64Encoded ? "base64" : undefined);
+		request.push(null);
+	}
+
+	// eslint-disable-next-line unicorn/consistent-function-scoping
+	function fixApiGatewayMultipleHeaders() {
+		for (const key of Object.keys(response.multiValueHeaders)) {
+			if (!Array.isArray(response.multiValueHeaders[key])) {
+				response.multiValueHeaders[key] = [response.multiValueHeaders[key]];
+			}
+		}
+	}
+
+	// eslint-disable-next-line unicorn/prevent-abbreviations
+	return { req: request, res };
+};
+
+module.exports = requestResponseMapper;

src/constants.js

@@ -1,3 +1,5 @@
+const path = require("path");
+
 const PROVIDERS = {
 	AWS: "AWS"
 };
@@ -8,9 +10,11 @@ const FILE_NAMES = {
 };
 
 const NEXT_CONFIG = "next.config.js";
+const COMPAT_LAYER_PATH = path.resolve(__dirname);
 
 module.exports = {
 	PROVIDERS,
 	FILE_NAMES,
-	NEXT_CONFIG
+	NEXT_CONFIG,
+	COMPAT_LAYER_PATH
 };

src/providers/aws/generateLambdas.js

@@ -3,19 +3,19 @@ const path = require("path");
 const { generateLambdaResource } = require("./resources/terraFormLambda");
 const { generateZipResource } = require("./resources/terraFormZip.js");
 const { getBuildPath, getServerlessBuildPath } = require("../../configuration");
-const { FILE_NAMES } = require("../../constants");
+const { COMPAT_LAYER_PATH, FILE_NAMES } = require("../../constants");
 const { getLambdaFiles } = require("../../shared");
 const FolderNotFoundError = require("../../errors/folderNotFoundError");
 
 function generateLambda(filename, thePath) {
 	const lambdaTemplate = `
 
+const compatLayer = require('./compatLayer.js');
 const page = require('./${filename}.original.js');
-const http = require('http')
 
 exports.render = (event, context, callback) => {
-	const server = new http.Server((req, res) => page.render(req, res));
-	server.listen(3000);
+	const { req, res } = compatLayer(event, callback);
+	page.render(req, res);
 };
 
 
@@ -63,8 +63,9 @@ function generateLambdas(write = false) {
 				 * 1. create a folder with name of the file
 				 * 2. copy the next file with a suffix .original.js
 				 * 3. create the lambda from the template
-				 * 4. generate the lambda resource
-				 * 5. generate the zip file resource
+				 * 4. copy the compact layer
+				 * 5. generate the lambda resource
+				 * 6. generate the zip file resource
 				 */
 				// 1.
 				const lambdaName = file.replace(".js", "");
@@ -78,11 +79,17 @@ function generateLambdas(write = false) {
 				generateLambda(lambdaName, buildPath);
 
 				// 4.
+				fs.copyFileSync(
+					path.resolve(COMPAT_LAYER_PATH, "./compatLayer.js"),
+					path.resolve(buildPath, "lambdas", lambdaName, "compatLayer.js")
+				);
+
+				// 5.
 				const lambdaResource = generateLambdaResource({ id: lambdaName });
 				lambdasResources[lambdaResource.resourceUniqueId] = lambdaResource.resource;
 				lambdasPermissions[lambdaResource.permissionUniqueId] = lambdaResource.permission;
 
-				// 5.
+				// 6.
 				const zipResource = generateZipResource({
 					id: lambdaName,
 					directoryName: lambdaName