Support Preview Mode

packages/compat-layers/lambda-at-edge-compat/__tests__/next-aws-cloudfront.response.test.js

@@ -144,6 +144,16 @@ describe("Response Tests", () => {
     });
   });
 
+  it("writeHead can be chained", () => {
+    const { res, responsePromise } = create({
+      request: { uri: "/", headers: {} }
+    });
+
+    res.writeHead(200, { "Content-Length": "1234" }).end();
+
+    return responsePromise;
+  });
+
   it("setHeader (multiple headers with same name)", () => {
     const { res, responsePromise } = create({
       request: {

packages/compat-layers/lambda-at-edge-compat/next-aws-cloudfront.js

@@ -214,6 +214,7 @@ const handler = (event) => {
     if (headers) {
       res.headers = Object.assign(res.headers, headers);
     }
+    return res;
   };
   res.write = (chunk) => {
     if (!response.body) {

packages/libs/lambda-at-edge/.gitignore

@@ -1,2 +1,2 @@
 !tests/**
-dist/
+dist/

packages/libs/lambda-at-edge/package.json

@@ -9,7 +9,7 @@
   "types": "dist/index.d.ts",
   "scripts": {
     "prepare": "yarn build",
-    "build": "tsc -p tsconfig.build.json"
+    "build": "rollup --config && tsc -p tsconfig.build.json"
   },
   "files": [
     "dist"
@@ -31,18 +31,27 @@
   },
   "homepage": "https://github.com/danielcondemarin/serverless-next.js#readme",
   "devDependencies": {
+    "@rollup/plugin-commonjs": "^15.0.0",
+    "@rollup/plugin-node-resolve": "^9.0.0",
+    "@rollup/plugin-typescript": "^5.0.2",
     "@types/aws-lambda": "^8.10.57",
+    "@types/cookie": "^0.4.0",
     "@types/execa": "^2.0.0",
     "@types/fs-extra": "^9.0.1",
+    "@types/jsonwebtoken": "^8.5.0",
     "@types/node": "^14.0.14",
     "@types/path-to-regexp": "^1.7.0",
+    "path-to-regexp": "^6.1.0",
+    "rollup": "^2.26.6",
+    "rollup-plugin-node-externals": "^2.2.0",
     "ts-loader": "^7.0.5",
     "typescript": "^3.9.6"
   },
   "dependencies": {
     "@zeit/node-file-trace": "^0.6.5",
+    "cookie": "^0.4.1",
     "execa": "^4.0.2",
     "fs-extra": "^9.0.1",
-    "path-to-regexp": "^6.1.0"
+    "jsonwebtoken": "^8.5.1"
   }
 }

packages/libs/lambda-at-edge/rollup.config.js

@@ -0,0 +1,32 @@
+import commonjs from "@rollup/plugin-commonjs";
+import typescript from "@rollup/plugin-typescript";
+import { nodeResolve } from "@rollup/plugin-node-resolve";
+import externals from "rollup-plugin-node-externals";
+
+const LOCAL_EXTERNALS = [
+  "./manifest.json",
+  "./routes-manifest.json",
+  "./prerender-manifest.json"
+];
+const NPM_EXTERNALS = ["aws-lambda", "aws-sdk/clients/s3"];
+
+const generateConfig = (filename) => ({
+  input: `./src/${filename}.ts`,
+  output: {
+    file: `./dist/${filename}.js`,
+    format: "cjs"
+  },
+  plugins: [
+    commonjs(),
+    externals({
+      exclude: "@sls-next/next-aws-cloudfront"
+    }),
+    nodeResolve(),
+    typescript({
+      tsconfig: "tsconfig.bundle.json"
+    })
+  ],
+  external: [...NPM_EXTERNALS, ...LOCAL_EXTERNALS]
+});
+
+export default ["default-handler", "api-handler"].map(generateConfig);

packages/libs/lambda-at-edge/src/build.ts

@@ -175,14 +175,6 @@ class Builder {
         join(this.outputDir, DEFAULT_LAMBDA_CODE_DIR, "manifest.json"),
         buildManifest
       ),
-      fse.copy(
-        require.resolve("@sls-next/next-aws-cloudfront"),
-        join(
-          this.outputDir,
-          DEFAULT_LAMBDA_CODE_DIR,
-          "node_modules/@sls-next/next-aws-cloudfront/index.js"
-        )
-      ),
       fse.copy(
         join(this.serverlessDir, "pages"),
         join(this.outputDir, DEFAULT_LAMBDA_CODE_DIR, "pages"),
@@ -245,14 +237,6 @@ class Builder {
         require.resolve("@sls-next/lambda-at-edge/dist/api-handler.js"),
         join(this.outputDir, API_LAMBDA_CODE_DIR, "index.js")
       ),
-      fse.copy(
-        require.resolve("@sls-next/next-aws-cloudfront"),
-        join(
-          this.outputDir,
-          API_LAMBDA_CODE_DIR,
-          "node_modules/@sls-next/next-aws-cloudfront/index.js"
-        )
-      ),
       fse.copy(
         join(this.serverlessDir, "pages/api"),
         join(this.outputDir, API_LAMBDA_CODE_DIR, "pages/api")

packages/libs/lambda-at-edge/src/default-handler.ts

@@ -5,6 +5,7 @@ import Manifest from "./manifest.json";
 // @ts-ignore
 import { basePath } from "./routes-manifest.json";
 import lambdaAtEdgeCompat from "@sls-next/next-aws-cloudfront";
+import cookie from "cookie";
 import {
   CloudFrontRequest,
   CloudFrontS3Origin,
@@ -21,6 +22,29 @@ import {
 import S3 from "aws-sdk/clients/s3";
 import { performance } from "perf_hooks";
 import { ServerResponse } from "http";
+import jsonwebtoken from "jsonwebtoken";
+
+const NEXT_PREVIEW_DATA_COOKIE = "__next_preview_data";
+const NEXT_PRERENDER_BYPASS_COOKIE = "__prerender_bypass";
+const defaultPreviewCookies = {
+  [NEXT_PRERENDER_BYPASS_COOKIE]: "",
+  [NEXT_PREVIEW_DATA_COOKIE]: ""
+};
+
+const getPreviewCookies = (request: CloudFrontRequest) => {
+  const targetCookie = request.headers.cookie || [];
+  return targetCookie.reduce((previewCookies, cookieObj) => {
+    const cookieValue = cookie.parse(cookieObj.value);
+    if (
+      cookieValue[NEXT_PREVIEW_DATA_COOKIE] &&
+      cookieValue[NEXT_PRERENDER_BYPASS_COOKIE]
+    ) {
+      return cookieValue as typeof defaultPreviewCookies;
+    } else {
+      return previewCookies;
+    }
+  }, defaultPreviewCookies);
+};
 
 const perfLogger = (logLambdaExecutionTimes: boolean): PerfLogger => {
   if (logLambdaExecutionTimes) {
@@ -211,11 +235,34 @@ const handleOriginRequest = async ({
   const normalisedS3DomainName = normaliseS3OriginDomain(s3Origin);
   const hasFallback = hasFallbackForUri(uri, prerenderManifest);
   const { now, log } = perfLogger(manifest.logLambdaExecutionTimes);
+  const previewCookies = getPreviewCookies(request);
+  const isPreviewRequest =
+    previewCookies[NEXT_PREVIEW_DATA_COOKIE] &&
+    previewCookies[NEXT_PRERENDER_BYPASS_COOKIE];
+
+  if (isPreviewRequest) {
+    try {
+      jsonwebtoken.verify(
+        previewCookies[NEXT_PREVIEW_DATA_COOKIE],
+        prerenderManifest.preview.previewModeSigningKey
+      );
+    } catch (e) {
+      console.error("Failed preview mode verification for URI:", request.uri);
+      return {
+        status: "403",
+        statusDescription: "Forbidden"
+      };
+    }
+  }
 
   s3Origin.domainName = normalisedS3DomainName;
 
-  // Check if we can serve request from S3
-  S3Check: if (isHTMLPage || isPublicFile || hasFallback || isDataReq) {
+  S3Check: if (
+    isPublicFile ||
+    (isHTMLPage && !isPreviewRequest) ||
+    (hasFallback && !isPreviewRequest) ||
+    (isDataReq && !isPreviewRequest)
+  ) {
     if (isHTMLPage || hasFallback) {
       s3Origin.path = `${basePath}/static-pages`;
       const pageName = uri === "/" ? "/index" : uri;
@@ -249,7 +296,7 @@ const handleOriginRequest = async ({
 
   const pagePath = router(manifest)(uri);
 
-  if (pagePath.endsWith(".html")) {
+  if (pagePath.endsWith(".html") && !isPreviewRequest) {
     s3Origin.path = `${basePath}/static-pages`;
     request.uri = pagePath.replace("pages", "");
     addS3HostHeader(request, normalisedS3DomainName);
@@ -272,7 +319,17 @@ const handleOriginRequest = async ({
     }
 
     // Render page
-    await page.render(req, res);
+    if (isDataReq) {
+      const { renderOpts } = await page.renderReqToHTML(
+        req,
+        res,
+        "passthrough"
+      );
+      res.setHeader("Content-Type", "application/json");
+      res.end(JSON.stringify(renderOpts.pageData));
+    } else {
+      await page.render(req, res);
+    }
   } catch (error) {
     // Set status to 500 so _error.js will render a 500 page
     console.error(

packages/libs/lambda-at-edge/tests/build/build.test.ts

@@ -156,7 +156,7 @@ describe("Builder Tests", () => {
 
   describe("Default Handler Artefact Files", () => {
     it("copies build files", async () => {
-      expect.assertions(7);
+      expect.assertions(6);
 
       const files = await fse.readdir(
         join(outputDir, `${DEFAULT_LAMBDA_CODE_DIR}`)
@@ -170,24 +170,15 @@ describe("Builder Tests", () => {
       const apiDirExists = await fse.pathExists(
         join(outputDir, `${DEFAULT_LAMBDA_CODE_DIR}/pages/api`)
       );
-      const compatLayerIncluded = await fse.pathExists(
-        join(
-          outputDir,
-          `${DEFAULT_LAMBDA_CODE_DIR}/node_modules/@sls-next/next-aws-cloudfront/index.js`
-        )
-      );
 
       expect(files).toEqual([
         "index.js",
         "manifest.json",
-        "node_modules",
         "pages",
         "prerender-manifest.json",
         "routes-manifest.json"
       ]);
 
-      expect(compatLayerIncluded).toEqual(true);
-
       // api pages should not be included in the default lambda
       expect(apiDirExists).toEqual(false);
 
@@ -203,7 +194,7 @@ describe("Builder Tests", () => {
 
   describe("API Handler Artefact Files", () => {
     it("copies build files", async () => {
-      expect.assertions(3);
+      expect.assertions(2);
 
       const files = await fse.readdir(
         join(outputDir, `${API_LAMBDA_CODE_DIR}`)
@@ -212,18 +203,9 @@ describe("Builder Tests", () => {
         join(outputDir, `${API_LAMBDA_CODE_DIR}/pages`)
       );
 
-      const compatLayerIncluded = await fse.pathExists(
-        join(
-          outputDir,
-          `${API_LAMBDA_CODE_DIR}/node_modules/@sls-next/next-aws-cloudfront/index.js`
-        )
-      );
-
-      expect(compatLayerIncluded).toEqual(true);
       expect(files).toEqual([
         "index.js",
         "manifest.json",
-        "node_modules",
         "pages",
         "routes-manifest.json"
       ]);

packages/libs/lambda-at-edge/tests/default-handler/default-build-manifest-with-trailing-slash.json

@@ -35,7 +35,8 @@
         "/api/getCustomers": "pages/api/getCustomers.js",
         "/_error": "pages/_error.js",
         "/erroredPage": "pages/erroredPage.js",
-        "/404": "pages/404.html"
+        "/404": "pages/404.html",
+        "/preview": "pages/preview.js"
       }
     },
     "html": {

packages/libs/lambda-at-edge/tests/default-handler/default-build-manifest.json

@@ -35,7 +35,8 @@
         "/api/getCustomers": "pages/api/getCustomers.js",
         "/_error": "pages/_error.js",
         "/erroredPage": "pages/erroredPage.js",
-        "/404": "pages/404.html"
+        "/404": "pages/404.html",
+        "/preview": "pages/preview.js"
       }
     },
     "html": {

packages/libs/lambda-at-edge/tests/default-handler/default-handler-with-basepath.test.ts

@@ -32,6 +32,15 @@ const mockPageRequire = (mockPagePath: string): void => {
 };
 
 describe("Lambda@Edge", () => {
+  let consoleWarnSpy: jest.SpyInstance;
+
+  beforeEach(() => {
+    consoleWarnSpy = jest.spyOn(console, "error").mockReturnValue();
+  });
+
+  afterEach(() => {
+    consoleWarnSpy.mockRestore();
+  });
   describe.each`
     trailingSlash
     ${false}
@@ -537,7 +546,11 @@ describe("Lambda@Edge", () => {
           const body = response.body as string;
           const decodedBody = new Buffer(body, "base64").toString("utf8");
 
-          expect(decodedBody).toEqual("pages/_error.js - 404");
+          expect(decodedBody).toEqual(
+            JSON.stringify({
+              page: "pages/_error.js - 404"
+            })
+          );
           expect(response.status).toEqual("404");
         }
       );