Publish Canary

- @vercel/build-utils@2.12.3-canary.42
 - vercel@23.1.3-canary.67
 - @vercel/client@10.2.3-canary.45
 - vercel-plugin-middleware@0.0.0-canary.19
 - vercel-plugin-go@1.0.0-canary.30
 - vercel-plugin-node@1.12.2-canary.34
 - vercel-plugin-python@1.0.0-canary.31
 - vercel-plugin-ruby@1.0.0-canary.30
 - @vercel/python@2.1.2-canary.2

.github/CODEOWNERS

@@ -4,24 +4,26 @@
 *                                        @TooTallNate
 /.github/workflows                       @AndyBitz @styfle
 /packages/frameworks                     @AndyBitz
-/packages/cli/src/commands/dev       @TooTallNate @styfle @AndyBitz
-/packages/cli/src/util/dev           @TooTallNate @styfle @AndyBitz
-/packages/cli/src/commands/domains   @javivelasco @mglagola @anatrajkovska
-/packages/cli/src/commands/certs     @javivelasco @mglagola @anatrajkovska
-/packages/cli/src/commands/env       @styfle @lucleray
-/packages/client                     @rdev @styfle @TooTallNate
-/packages/build-utils                @styfle @AndyBitz @TooTallNate
-/packages/node                       @styfle @TooTallNate @lucleray
-/packages/node-bridge                @styfle @TooTallNate @lucleray
-/packages/next                       @Timer @ijjk
-/packages/go                         @styfle @TooTallNate
-/packages/python                     @styfle @TooTallNate
-/packages/ruby                       @styfle @coetry @TooTallNate
-/packages/static-build               @styfle @AndyBitz
-/packages/routing-utils              @styfle @dav-is @ijjk
-/examples                                @mcsdevv @timothyis
+/packages/cli/src/commands/build         @TooTallNate @styfle @AndyBitz @gdborton @jaredpalmer
+/packages/cli/src/commands/dev           @TooTallNate @styfle @AndyBitz
+/packages/cli/src/util/dev               @TooTallNate @styfle @AndyBitz
+/packages/cli/src/commands/domains       @javivelasco @mglagola @anatrajkovska
+/packages/cli/src/commands/certs         @javivelasco @mglagola @anatrajkovska
+/packages/cli/src/commands/env           @styfle @lucleray
+/packages/client                         @styfle @TooTallNate
+/packages/build-utils                    @styfle @AndyBitz @TooTallNate
+/packages/middleware                     @gdborton @javivelasco
+/packages/node                           @styfle @TooTallNate @lucleray
+/packages/node-bridge                    @styfle @TooTallNate @lucleray
+/packages/next                           @Timer @ijjk
+/packages/go                             @styfle @TooTallNate
+/packages/python                         @styfle @TooTallNate
+/packages/ruby                           @styfle @TooTallNate
+/packages/static-build                   @styfle @AndyBitz
+/packages/routing-utils                  @styfle @dav-is @ijjk
+/examples                                @mcsdevv
 /examples/create-react-app               @Timer
 /examples/nextjs                         @timneutkens @Timer
-/examples/hugo                           @mcsdevv @timothyis @styfle
-/examples/jekyll                         @mcsdevv @timothyis @styfle
-/examples/zola                           @mcsdevv @timothyis @styfle
+/examples/hugo                           @mcsdevv @styfle
+/examples/jekyll                         @mcsdevv @styfle
+/examples/zola                           @mcsdevv @styfle

packages/build-utils/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/build-utils",
-  "version": "2.12.3-canary.31",
+  "version": "2.12.3-canary.42",
   "license": "MIT",
   "main": "./dist/index.js",
   "types": "./dist/index.d.js",
@@ -30,7 +30,7 @@
     "@types/node-fetch": "^2.1.6",
     "@types/semver": "6.0.0",
     "@types/yazl": "^2.4.1",
-    "@vercel/frameworks": "0.5.1-canary.16",
+    "@vercel/frameworks": "0.5.1-canary.17",
     "@vercel/ncc": "0.24.0",
     "aggregate-error": "3.0.1",
     "async-retry": "1.2.3",

packages/build-utils/src/convert-runtime-to-plugin.ts

@@ -1,11 +1,10 @@
 import fs from 'fs-extra';
-import { join, dirname, parse, relative } from 'path';
+import { join, parse, relative, dirname, basename, extname } from 'path';
 import glob from './fs/glob';
 import { normalizePath } from './fs/normalize-path';
 import { FILES_SYMBOL, Lambda } from './lambda';
-import type FileBlob from './file-blob';
 import type { BuildOptions, Files } from './types';
-import { getIgnoreFilter } from '.';
+import { debug, getIgnoreFilter } from '.';
 
 // `.output` was already created by the Build Command, so we have
 // to ensure its contents don't get bundled into the Lambda. Similarily,
@@ -87,10 +86,10 @@ export function convertRuntimeToPlugin(
 
     const pages: { [key: string]: any } = {};
     const pluginName = packageName.replace('vercel-plugin-', '');
+    const outputPath = join(workPath, '.output');
 
     const traceDir = join(
-      workPath,
-      `.output`,
+      outputPath,
       `inputs`,
       // Legacy Runtimes can only provide API Routes, so that's
       // why we can use this prefix for all of them. Here, we have to
@@ -101,6 +100,8 @@ export function convertRuntimeToPlugin(
 
     await fs.ensureDir(traceDir);
 
+    const entryRoot = join(outputPath, 'server', 'pages');
+
     for (const entrypoint of Object.keys(entrypoints)) {
       const { output } = await buildRuntime({
         files: sourceFilesPreBuild,
@@ -111,38 +112,10 @@ export function convertRuntimeToPlugin(
         },
         meta: {
           avoidTopLevelInstall: true,
+          skipDownload: true,
         },
       });
 
-      // Legacy Runtimes tend to pollute the `workPath` with compiled results,
-      // because the `workPath` used to be a place that was a place where they could
-      // just put anything, but nowadays it's the working directory of the `vercel build`
-      // command, which is the place where the developer keeps their source files,
-      // so we don't want to pollute this space unnecessarily. That means we have to clean
-      // up files that were created by the build, which is done further below.
-      const sourceFilesAfterBuild = await getSourceFiles(
-        workPath,
-        ignoreFilter
-      );
-
-      // Further down, we will need the filename of the Lambda handler
-      // for placing it inside `server/pages/api`, but because Legacy Runtimes
-      // don't expose the filename directly, we have to construct it
-      // from the handler name, and then find the matching file further below,
-      // because we don't yet know its extension here.
-      const handler = output.handler;
-      const handlerMethod = handler.split('.').reverse()[0];
-      const handlerFileName = handler.replace(`.${handlerMethod}`, '');
-
-      pages[entrypoint] = {
-        handler: handler,
-        runtime: output.runtime,
-        memory: output.memory,
-        maxDuration: output.maxDuration,
-        environment: output.environment,
-        allowQuery: output.allowQuery,
-      };
-
       // @ts-ignore This symbol is a private API
       const lambdaFiles: Files = output[FILES_SYMBOL];
 
@@ -156,95 +129,168 @@ export function convertRuntimeToPlugin(
         }
       }
 
-      const handlerFilePath = Object.keys(lambdaFiles).find(item => {
-        return parse(item).name === handlerFileName;
-      });
+      let handlerFileBase = output.handler;
+      let handlerFile = lambdaFiles[handlerFileBase];
+      let handlerHasImport = false;
 
-      const handlerFileOrigin = lambdaFiles[handlerFilePath || ''].fsPath;
+      const { handler } = output;
+      const handlerMethod = handler.split('.').pop();
+      const handlerFileName = handler.replace(`.${handlerMethod}`, '');
 
-      if (!handlerFileOrigin) {
+      // For compiled languages, the launcher file for the Lambda generated
+      // by the Legacy Runtime matches the `handler` defined for it, but for
+      // interpreted languages, the `handler` consists of the launcher file name
+      // without an extension, plus the name of the method inside of that file
+      // that should be invoked, so we have to construct the file path explicitly.
+      if (!handlerFile) {
+        handlerFileBase = handlerFileName + ext;
+        handlerFile = lambdaFiles[handlerFileBase];
+        handlerHasImport = true;
+      }
+
+      if (!handlerFile || !handlerFile.fsPath) {
         throw new Error(
-          `Could not find a handler file. Please ensure that the list of \`files\` defined for the returned \`Lambda\` contains a file with the name ${handlerFileName} (+ any extension).`
+          `Could not find a handler file. Please ensure that \`files\` for the returned \`Lambda\` contains an \`FileFsRef\` named "${handlerFileBase}" with a valid \`fsPath\`.`
         );
       }
 
-      const entry = join(workPath, '.output', 'server', 'pages', entrypoint);
+      const handlerExtName = extname(handlerFile.fsPath);
 
+      const entryBase = basename(entrypoint).replace(ext, handlerExtName);
+      const entryPath = join(dirname(entrypoint), entryBase);
+      const entry = join(entryRoot, entryPath);
+
+      // Create the parent directory of the API Route that will be created
+      // for the current entrypoint inside of `.output/server/pages/api`.
       await fs.ensureDir(dirname(entry));
-      await linkOrCopy(handlerFileOrigin, entry);
 
-      const toRemove = [];
+      // For compiled languages, the launcher file will be binary and therefore
+      // won't try to import a user-provided request handler (instead, it will
+      // contain it). But for interpreted languages, the launcher might try to
+      // load a user-provided request handler from the source file instead of bundling
+      // it, so we have to adjust the import statement inside the launcher to point
+      // to the respective source file. Previously, Legacy Runtimes simply expected
+      // the user-provided request-handler to be copied right next to the launcher,
+      // but with the new File System API, files won't be moved around unnecessarily.
+      if (handlerHasImport) {
+        const { fsPath } = handlerFile;
+        const encoding = 'utf-8';
 
-      // You can find more details about this at the point where the
-      // `sourceFilesAfterBuild` is created originally.
-      for (const file in sourceFilesAfterBuild) {
-        if (!sourceFilesPreBuild[file]) {
-          const path = sourceFilesAfterBuild[file].fsPath;
-          toRemove.push(fs.remove(path));
+        // This is the true directory of the user-provided request handler in the
+        // source files, so that's what we will use as an import path in the launcher.
+        const locationPrefix = relative(entry, outputPath);
+
+        let handlerContent = await fs.readFile(fsPath, encoding);
+
+        const importPaths = [
+          // This is the full entrypoint path, like `./api/test.py`. In our tests
+          // Python didn't support importing from a parent directory without using different
+          // code in the launcher that registers it as a location for modules and then changing
+          // the importing syntax, but continuing to import it like before seems to work. If
+          // other languages need this, we should consider excluding Python explicitly.
+          // `./${entrypoint}`,
+
+          // This is the entrypoint path without extension, like `api/test`
+          entrypoint.slice(0, -ext.length),
+        ];
+
+        // Generate a list of regular expressions that we can use for
+        // finding matches, but only allow matches if the import path is
+        // wrapped inside single (') or double quotes (").
+        const patterns = importPaths.map(path => {
+          // eslint-disable-next-line no-useless-escape
+          return new RegExp(`('|")(${path.replace(/\./g, '\\.')})('|")`, 'g');
+        });
+
+        let replacedMatch = null;
+
+        for (const pattern of patterns) {
+          const newContent = handlerContent.replace(
+            pattern,
+            (_, p1, p2, p3) => {
+              return `${p1}${join(locationPrefix, p2)}${p3}`;
+            }
+          );
+
+          if (newContent !== handlerContent) {
+            debug(
+              `Replaced "${pattern}" inside "${entry}" to ensure correct import of user-provided request handler`
+            );
+
+            handlerContent = newContent;
+            replacedMatch = true;
+          }
         }
+
+        if (!replacedMatch) {
+          new Error(
+            `No replacable matches for "${importPaths[0]}" or "${importPaths[1]}" found in "${fsPath}"`
+          );
+        }
+
+        await fs.writeFile(entry, handlerContent, encoding);
+      } else {
+        await fs.copy(handlerFile.fsPath, entry);
       }
 
-      await Promise.all(toRemove);
+      // Legacy Runtimes based on interpreted languages will create a new launcher file
+      // for every entrypoint, but they will create each one inside `workPath`, which means that
+      // the launcher for one entrypoint will overwrite the launcher provided for the previous
+      // entrypoint. That's why, above, we copy the file contents into the new destination (and
+      // optionally transform them along the way), instead of linking. We then also want to remove
+      // the copy origin right here, so that the `workPath` doesn't contain a useless launcher file
+      // once the build has finished running.
+      await fs.remove(handlerFile.fsPath);
+      debug(`Removed temporary file "${handlerFile.fsPath}"`);
 
-      const tracedFiles: {
-        absolutePath: string;
-        relativePath: string;
-      }[] = [];
-
-      Object.entries(lambdaFiles).forEach(async ([relPath, file]) => {
-        const newPath = join(traceDir, relPath);
-
-        // The handler was already moved into position above.
-        if (relPath === handlerFilePath) {
-          return;
-        }
-
-        tracedFiles.push({ absolutePath: newPath, relativePath: relPath });
-
-        if (file.fsPath) {
-          await linkOrCopy(file.fsPath, newPath);
-        } else if (file.type === 'FileBlob') {
-          const { data, mode } = file as FileBlob;
-          await fs.writeFile(newPath, data, { mode });
-        } else {
-          throw new Error(`Unknown file type: ${file.type}`);
-        }
-      });
-
-      const nft = join(
-        workPath,
-        '.output',
-        'server',
-        'pages',
-        `${entrypoint}.nft.json`
-      );
+      const nft = `${entry}.nft.json`;
 
       const json = JSON.stringify({
-        version: 1,
-        files: tracedFiles.map(file => ({
-          input: normalizePath(relative(nft, file.absolutePath)),
-          output: normalizePath(file.relativePath),
-        })),
+        version: 2,
+        files: Object.keys(lambdaFiles)
+          .map(file => {
+            const { fsPath } = lambdaFiles[file];
+
+            if (!fsPath) {
+              throw new Error(
+                `File "${file}" is missing valid \`fsPath\` property`
+              );
+            }
+
+            // The handler was already moved into position above.
+            if (file === handlerFileBase) {
+              return;
+            }
+
+            return normalizePath(relative(dirname(nft), fsPath));
+          })
+          .filter(Boolean),
       });
 
-      await fs.ensureDir(dirname(nft));
       await fs.writeFile(nft, json);
+
+      // Add an entry that will later on be added to the `functions-manifest.json`
+      // file that is placed inside of the `.output` directory.
+      pages[normalizePath(entryPath)] = {
+        // Because the underlying file used as a handler was placed
+        // inside `.output/server/pages/api`, it no longer has the name it originally
+        // had and is now named after the API Route that it's responsible for,
+        // so we have to adjust the name of the Lambda handler accordingly.
+        handler: handler.replace(handlerFileName, parse(entry).name),
+        runtime: output.runtime,
+        memory: output.memory,
+        maxDuration: output.maxDuration,
+        environment: output.environment,
+        allowQuery: output.allowQuery,
+      };
     }
 
+    // Add any Serverless Functions that were exposed by the Legacy Runtime
+    // to the `functions-manifest.json` file provided in `.output`.
     await updateFunctionsManifest({ workPath, pages });
   };
 }
 
-async function linkOrCopy(existingPath: string, newPath: string) {
-  try {
-    await fs.createLink(existingPath, newPath);
-  } catch (err: any) {
-    if (err.code !== 'EEXIST') {
-      await fs.copyFile(existingPath, newPath);
-    }
-  }
-}
-
 async function readJson(filePath: string): Promise<{ [key: string]: any }> {
   try {
     const str = await fs.readFile(filePath, 'utf8');
@@ -275,7 +321,7 @@ export async function updateFunctionsManifest({
   );
   const functionsManifest = await readJson(functionsManifestPath);
 
-  if (!functionsManifest.version) functionsManifest.version = 1;
+  if (!functionsManifest.version) functionsManifest.version = 2;
   if (!functionsManifest.pages) functionsManifest.pages = {};
 
   for (const [pageKey, pageConfig] of Object.entries(pages)) {

packages/build-utils/test/unit.convert-runtime-to-plugin.test.ts

@@ -62,7 +62,6 @@ describe('convert-runtime-to-plugin', () => {
       return { output: lambda };
     };
 
-    const lambdaFiles = await fsToJson(workPath);
     const packageName = 'vercel-plugin-python';
     const build = await convertRuntimeToPlugin(buildRuntime, packageName, ext);
 
@@ -70,14 +69,8 @@ describe('convert-runtime-to-plugin', () => {
 
     const output = await fsToJson(join(workPath, '.output'));
 
-    delete lambdaFiles['vercel.json'];
-    delete lambdaFiles['vc__handler__python.py'];
-
     expect(output).toMatchObject({
       'functions-manifest.json': expect.stringContaining('{'),
-      inputs: {
-        'api-routes-python': lambdaFiles,
-      },
       server: {
         pages: {
           api: {
@@ -96,50 +89,30 @@ describe('convert-runtime-to-plugin', () => {
 
     const funcManifest = JSON.parse(output['functions-manifest.json']);
     expect(funcManifest).toMatchObject({
-      version: 1,
+      version: 2,
       pages: {
-        'api/index.py': lambdaOptions,
-        'api/users/get.py': lambdaOptions,
-        'api/users/post.py': { ...lambdaOptions, memory: 512 },
+        'api/index.py': { ...lambdaOptions, handler: 'index.vc_handler' },
+        'api/users/get.py': { ...lambdaOptions, handler: 'get.vc_handler' },
+        'api/users/post.py': {
+          ...lambdaOptions,
+          handler: 'post.vc_handler',
+          memory: 512,
+        },
       },
     });
 
     const indexJson = JSON.parse(output.server.pages.api['index.py.nft.json']);
     expect(indexJson).toMatchObject({
-      version: 1,
+      version: 2,
       files: [
-        {
-          input: `../../../../inputs/api-routes-python/api/db/[id].py`,
-          output: 'api/db/[id].py',
-        },
-        {
-          input: `../../../../inputs/api-routes-python/api/index.py`,
-          output: 'api/index.py',
-        },
-        {
-          input: `../../../../inputs/api-routes-python/api/project/[aid]/[bid]/index.py`,
-          output: 'api/project/[aid]/[bid]/index.py',
-        },
-        {
-          input: `../../../../inputs/api-routes-python/api/users/get.py`,
-          output: 'api/users/get.py',
-        },
-        {
-          input: `../../../../inputs/api-routes-python/api/users/post.py`,
-          output: 'api/users/post.py',
-        },
-        {
-          input: `../../../../inputs/api-routes-python/file.txt`,
-          output: 'file.txt',
-        },
-        {
-          input: `../../../../inputs/api-routes-python/util/date.py`,
-          output: 'util/date.py',
-        },
-        {
-          input: `../../../../inputs/api-routes-python/util/math.py`,
-          output: 'util/math.py',
-        },
+        '../../../../api/db/[id].py',
+        '../../../../api/index.py',
+        '../../../../api/project/[aid]/[bid]/index.py',
+        '../../../../api/users/get.py',
+        '../../../../api/users/post.py',
+        '../../../../file.txt',
+        '../../../../util/date.py',
+        '../../../../util/math.py',
       ],
     });
 
@@ -147,40 +120,16 @@ describe('convert-runtime-to-plugin', () => {
       output.server.pages.api.users['get.py.nft.json']
     );
     expect(getJson).toMatchObject({
-      version: 1,
+      version: 2,
       files: [
-        {
-          input: `../../../../../inputs/api-routes-python/api/db/[id].py`,
-          output: 'api/db/[id].py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/index.py`,
-          output: 'api/index.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/project/[aid]/[bid]/index.py`,
-          output: 'api/project/[aid]/[bid]/index.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/users/get.py`,
-          output: 'api/users/get.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/users/post.py`,
-          output: 'api/users/post.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/file.txt`,
-          output: 'file.txt',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/util/date.py`,
-          output: 'util/date.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/util/math.py`,
-          output: 'util/math.py',
-        },
+        '../../../../../api/db/[id].py',
+        '../../../../../api/index.py',
+        '../../../../../api/project/[aid]/[bid]/index.py',
+        '../../../../../api/users/get.py',
+        '../../../../../api/users/post.py',
+        '../../../../../file.txt',
+        '../../../../../util/date.py',
+        '../../../../../util/math.py',
       ],
     });
 
@@ -188,40 +137,16 @@ describe('convert-runtime-to-plugin', () => {
       output.server.pages.api.users['post.py.nft.json']
     );
     expect(postJson).toMatchObject({
-      version: 1,
+      version: 2,
       files: [
-        {
-          input: `../../../../../inputs/api-routes-python/api/db/[id].py`,
-          output: 'api/db/[id].py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/index.py`,
-          output: 'api/index.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/project/[aid]/[bid]/index.py`,
-          output: 'api/project/[aid]/[bid]/index.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/users/get.py`,
-          output: 'api/users/get.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/api/users/post.py`,
-          output: 'api/users/post.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/file.txt`,
-          output: 'file.txt',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/util/date.py`,
-          output: 'util/date.py',
-        },
-        {
-          input: `../../../../../inputs/api-routes-python/util/math.py`,
-          output: 'util/math.py',
-        },
+        '../../../../../api/db/[id].py',
+        '../../../../../api/index.py',
+        '../../../../../api/project/[aid]/[bid]/index.py',
+        '../../../../../api/users/get.py',
+        '../../../../../api/users/post.py',
+        '../../../../../file.txt',
+        '../../../../../util/date.py',
+        '../../../../../util/math.py',
       ],
     });
 

packages/cli/README.md

@@ -34,7 +34,7 @@ Finally, [connect your Git repository to Vercel](https://vercel.com/docs/git) an
 
 ## Documentation
 
-For details on how to use Vercel CLI, check out our [documentation](https://vercel.com/docs).
+For details on how to use Vercel CLI, check out our [documentation](https://vercel.com/docs/cli).
 
 ## Local Development
 

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "vercel",
-  "version": "23.1.3-canary.52",
+  "version": "23.1.3-canary.67",
   "preferGlobal": true,
   "license": "Apache-2.0",
   "description": "The command-line interface for Vercel",
@@ -43,14 +43,14 @@
     "node": ">= 12"
   },
   "dependencies": {
-    "@vercel/build-utils": "2.12.3-canary.31",
+    "@vercel/build-utils": "2.12.3-canary.42",
     "@vercel/go": "1.2.4-canary.4",
     "@vercel/node": "1.12.2-canary.7",
-    "@vercel/python": "2.1.2-canary.1",
-    "@vercel/ruby": "1.2.8-canary.6",
+    "@vercel/python": "2.1.2-canary.2",
+    "@vercel/ruby": "1.2.10-canary.0",
     "update-notifier": "4.1.0",
-    "vercel-plugin-middleware": "0.0.0-canary.7",
-    "vercel-plugin-node": "1.12.2-canary.23"
+    "vercel-plugin-middleware": "0.0.0-canary.19",
+    "vercel-plugin-node": "1.12.2-canary.34"
   },
   "devDependencies": {
     "@next/env": "11.1.2",
@@ -90,7 +90,7 @@
     "@types/update-notifier": "5.1.0",
     "@types/which": "1.3.2",
     "@types/write-json-file": "2.2.1",
-    "@vercel/frameworks": "0.5.1-canary.16",
+    "@vercel/frameworks": "0.5.1-canary.17",
     "@vercel/ncc": "0.24.0",
     "@vercel/nft": "0.17.0",
     "@zeit/fun": "0.11.2",

packages/cli/src/commands/build.ts

@@ -5,16 +5,16 @@ import {
   GlobOptions,
   scanParentDirs,
   spawnAsync,
+  glob as buildUtilsGlob,
 } from '@vercel/build-utils';
 import { nodeFileTrace } from '@vercel/nft';
 import Sema from 'async-sema';
 import chalk from 'chalk';
 import { SpawnOptions } from 'child_process';
 import { assert } from 'console';
-import { createHash } from 'crypto';
 import fs from 'fs-extra';
 import ogGlob from 'glob';
-import { dirname, isAbsolute, join, parse, relative, resolve } from 'path';
+import { dirname, isAbsolute, join, parse, relative } from 'path';
 import pluralize from 'pluralize';
 import Client from '../util/client';
 import { VercelConfig } from '../util/dev/types';
@@ -353,13 +353,19 @@ export default async function main(client: Client) {
     }
 
     // We cannot rely on the `framework` alone, as it might be a static export,
-    // and the current build might use a differnt project that's not in the settings.
+    // and the current build might use a different project that's not in the settings.
     const isNextOutput = Boolean(dotNextDir);
-    const outputDir = isNextOutput ? OUTPUT_DIR : join(OUTPUT_DIR, 'static');
+    const nextExport = await getNextExportStatus(dotNextDir);
+    const outputDir =
+      isNextOutput && !nextExport ? OUTPUT_DIR : join(OUTPUT_DIR, 'static');
+    const getDistDir = framework.getFsOutputDir || framework.getOutputDirName;
     const distDir =
+      (nextExport?.exportDetail.outDirectory
+        ? relative(cwd, nextExport.exportDetail.outDirectory)
+        : false) ||
       dotNextDir ||
       userOutputDirectory ||
-      (await framework.getFsOutputDir(cwd));
+      (await getDistDir(cwd));
 
     await fs.ensureDir(join(cwd, outputDir));
 
@@ -443,7 +449,53 @@ export default async function main(client: Client) {
     }
 
     // Special Next.js processing.
-    if (isNextOutput) {
+    if (nextExport) {
+      client.output.debug('Found `next export` output.');
+
+      const htmlFiles = await buildUtilsGlob(
+        '**/*.html',
+        join(cwd, OUTPUT_DIR, 'static')
+      );
+
+      if (nextExport.exportDetail.success !== true) {
+        client.output.error(
+          `Export of Next.js app failed. Please check your build logs.`
+        );
+        process.exit(1);
+      }
+
+      await fs.mkdirp(join(cwd, OUTPUT_DIR, 'server', 'pages'));
+      await fs.mkdirp(join(cwd, OUTPUT_DIR, 'static'));
+
+      await Promise.all(
+        Object.keys(htmlFiles).map(async fileName => {
+          await sema.acquire();
+
+          const input = join(cwd, OUTPUT_DIR, 'static', fileName);
+          const target = join(cwd, OUTPUT_DIR, 'server', 'pages', fileName);
+
+          await fs.mkdirp(dirname(target));
+
+          await fs.promises.rename(input, target).finally(() => {
+            sema.release();
+          });
+        })
+      );
+
+      for (const file of [
+        'BUILD_ID',
+        'images-manifest.json',
+        'routes-manifest.json',
+        'build-manifest.json',
+      ]) {
+        const input = join(nextExport.dotNextDir, file);
+
+        if (fs.existsSync(input)) {
+          // Do not use `smartCopy`, since we want to overwrite if they already exist.
+          await fs.copyFile(input, join(OUTPUT_DIR, file));
+        }
+      }
+    } else if (isNextOutput) {
       // The contents of `.output/static` should be placed inside of `.output/static/_next/static`
       const tempStatic = '___static';
       await fs.rename(
@@ -584,30 +636,15 @@ export default async function main(client: Client) {
             ],
           });
           fileList.delete(relative(cwd, f));
-          await resolveNftToOutput({
-            client,
-            baseDir,
-            outputDir: OUTPUT_DIR,
-            nftFileName: f.replace(ext, '.js.nft.json'),
-            distDir,
-            nft: {
-              version: 1,
-              files: Array.from(fileList).map(fileListEntry =>
-                relative(dir, fileListEntry)
-              ),
-            },
-          });
-        }
-      } else {
-        for (let f of nftFiles) {
-          const json = await fs.readJson(f);
-          await resolveNftToOutput({
-            client,
-            baseDir,
-            outputDir: OUTPUT_DIR,
-            nftFileName: f,
-            nft: json,
-            distDir,
+
+          const nftFileName = f.replace(ext, '.js.nft.json');
+          client.output.debug(`Creating ${nftFileName}`);
+
+          await fs.writeJSON(nftFileName, {
+            version: 2,
+            files: Array.from(fileList).map(fileListEntry =>
+              relative(dir, fileListEntry)
+            ),
           });
         }
       }
@@ -631,15 +668,7 @@ export default async function main(client: Client) {
             const originalPath = join(requiredServerFilesJson.appDir, i);
             const relPath = join(OUTPUT_DIR, relative(distDir, originalPath));
 
-            const absolutePath = join(cwd, relPath);
-            const output = relative(baseDir, absolutePath);
-
-            return relPath === output
-              ? relPath
-              : {
-                  input: relPath,
-                  output,
-                };
+            return relPath;
           }),
         });
       }
@@ -797,83 +826,51 @@ async function glob(pattern: string, options: GlobOptions): Promise<string[]> {
 }
 
 /**
- * Computes a hash for the given buf.
- *
- * @param {Buffer} file data
- * @return {String} hex digest
+ * Files will only exist when `next export` was used.
  */
-function hash(buf: Buffer): string {
-  return createHash('sha1').update(buf).digest('hex');
-}
-
-interface NftFile {
-  version: number;
-  files: (string | { input: string; output: string })[];
-}
-
-// resolveNftToOutput takes nft file and moves all of its trace files
-// into the specified directory + `inputs`, (renaming them to their hash + ext) and
-// subsequently updating the original nft file accordingly. This is done
-// to make the `.output` directory be self-contained, so that it works
-// properly with `vc --prebuilt`.
-async function resolveNftToOutput({
-  client,
-  baseDir,
-  outputDir,
-  nftFileName,
-  distDir,
-  nft,
-}: {
-  client: Client;
-  baseDir: string;
-  outputDir: string;
-  nftFileName: string;
-  distDir: string;
-  nft: NftFile;
-}) {
-  client.output.debug(`Processing and resolving ${nftFileName}`);
-  await fs.ensureDir(join(outputDir, 'inputs'));
-  const newFilesList: NftFile['files'] = [];
-
-  // If `distDir` is a subdirectory, then the input has to be resolved to where the `.output` directory will be.
-  const relNftFileName = relative(outputDir, nftFileName);
-  const origNftFilename = join(distDir, relNftFileName);
-
-  if (relNftFileName.startsWith('cache/')) {
-    // No need to process the `cache/` directory.
-    // Paths in it might also not be relative to `cache` itself.
-    return;
+async function getNextExportStatus(dotNextDir: string | null) {
+  if (!dotNextDir) {
+    return null;
   }
 
-  for (let fileEntity of nft.files) {
-    const relativeInput =
-      typeof fileEntity === 'string' ? fileEntity : fileEntity.input;
-    const fullInput = resolve(join(parse(origNftFilename).dir, relativeInput));
+  const exportDetail: {
+    success: boolean;
+    outDirectory: string;
+  } | null = await fs
+    .readJson(join(dotNextDir, 'export-detail.json'))
+    .catch(error => {
+      if (error.code === 'ENOENT') {
+        return null;
+      }
 
-    // if the resolved path is NOT in the .output directory we move in it there
-    if (!fullInput.includes(distDir)) {
-      const { ext } = parse(fullInput);
-      const raw = await fs.readFile(fullInput);
-      const newFilePath = join(outputDir, 'inputs', hash(raw) + ext);
-      smartCopy(client, fullInput, newFilePath);
+      throw error;
+    });
 
-      // We have to use `baseDir` instead of `cwd`, because we want to
-      // mount everything from there (especially `node_modules`).
-      // This is important for NPM Workspaces where `node_modules` is not
-      // in the directory of the workspace.
-      const output = relative(baseDir, fullInput).replace('.output', '.next');
-
-      newFilesList.push({
-        input: relative(parse(nftFileName).dir, newFilePath),
-        output,
-      });
-    } else {
-      newFilesList.push(relativeInput);
-    }
+  if (!exportDetail) {
+    return null;
   }
-  // Update the .nft.json with new input and output mapping
-  await fs.writeJSON(nftFileName, {
-    ...nft,
-    files: newFilesList,
-  });
+
+  const exportMarker: {
+    version: 1;
+    exportTrailingSlash: boolean;
+    hasExportPathMap: boolean;
+  } | null = await fs
+    .readJSON(join(dotNextDir, 'export-marker.json'))
+    .catch(error => {
+      if (error.code === 'ENOENT') {
+        return null;
+      }
+
+      throw error;
+    });
+
+  return {
+    dotNextDir,
+    exportDetail,
+    exportMarker: {
+      trailingSlash: exportMarker?.hasExportPathMap
+        ? exportMarker.exportTrailingSlash
+        : false,
+    },
+  };
 }

packages/cli/src/commands/deploy/index.ts

@@ -447,6 +447,7 @@ export default async (client: Client) => {
       forceNew: argv['--force'],
       withCache: argv['--with-cache'],
       prebuilt: argv['--prebuilt'],
+      rootDirectory,
       quiet,
       wantsPublic: argv['--public'] || localConfig.public,
       isFile,

packages/cli/src/util/deploy/process-deployment.ts

@@ -52,6 +52,7 @@ export default async function processDeployment({
   isSettingUpProject: boolean;
   skipAutoDetectionConfirmation?: boolean;
   cwd?: string;
+  rootDirectory?: string;
 }) {
   let {
     now,
@@ -64,6 +65,7 @@ export default async function processDeployment({
     nowConfig,
     quiet,
     prebuilt,
+    rootDirectory,
   } = args;
 
   const { debug } = output;
@@ -86,6 +88,7 @@ export default async function processDeployment({
     force,
     withCache,
     prebuilt,
+    rootDirectory,
     skipAutoDetectionConfirmation,
   };
 

packages/cli/src/util/index.ts

@@ -37,6 +37,7 @@ export interface CreateOptions {
   project?: string;
   wantsPublic: boolean;
   prebuilt?: boolean;
+  rootDirectory?: string;
   meta: Dictionary<string>;
   regions?: string[];
   quiet?: boolean;
@@ -113,6 +114,7 @@ export default class Now extends EventEmitter {
       name,
       project,
       prebuilt = false,
+      rootDirectory,
       wantsPublic,
       meta,
       regions,
@@ -168,6 +170,7 @@ export default class Now extends EventEmitter {
       skipAutoDetectionConfirmation,
       cwd,
       prebuilt,
+      rootDirectory,
     });
 
     if (deployment && deployment.warnings) {

packages/cli/test/fixtures/unit/edge-middleware-strict/_middleware.ts

@@ -0,0 +1,6 @@
+export default function (req) {
+  const isStrict = (function () {
+    return !this;
+  })();
+  return new Response('is strict mode? ' + (isStrict ? 'yes' : 'no'));
+}

packages/cli/test/util/dev/server.test.ts

@@ -385,4 +385,13 @@ describe('DevServer', () => {
       );
     })
   );
+
+  it(
+    'should run middleware in strict mode',
+    testFixture('edge-middleware-strict', async server => {
+      const response = await fetch(`${server.address}/index.html`);
+      const body = await response.text();
+      expect(body).toStrictEqual('is strict mode? yes');
+    })
+  );
 });

packages/client/.gitignore

@@ -6,3 +6,5 @@ node_modules
 !tests/fixtures/nowignore/node_modules
 !tests/fixtures/vercelignore-allow-nodemodules/node_modules
 !tests/fixtures/vercelignore-allow-nodemodules/sub/node_modules
+!tests/fixtures/file-system-api/.output
+!tests/fixtures/file-system-api-root-directory/**/.output

packages/client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/client",
-  "version": "10.2.3-canary.32",
+  "version": "10.2.3-canary.45",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",
   "homepage": "https://vercel.com",
@@ -40,7 +40,7 @@
     ]
   },
   "dependencies": {
-    "@vercel/build-utils": "2.12.3-canary.31",
+    "@vercel/build-utils": "2.12.3-canary.42",
     "@zeit/fetch": "5.2.0",
     "async-retry": "1.2.3",
     "async-sema": "3.0.0",

packages/client/src/create-deployment.ts

@@ -1,12 +1,12 @@
 import { lstatSync } from 'fs-extra';
 
 import { relative, isAbsolute } from 'path';
-import hashes, { mapToObject } from './utils/hashes';
+import { hashes, mapToObject, resolveNftJsonFiles } from './utils/hashes';
 import { upload } from './upload';
 import { buildFileTree, createDebug, parseVercelConfig } from './utils';
 import { DeploymentError } from './errors';
 import {
-  NowConfig,
+  VercelConfig,
   VercelClientOptions,
   DeploymentOptions,
   DeploymentEventType,
@@ -16,7 +16,7 @@ export default function buildCreateDeployment() {
   return async function* createDeployment(
     clientOptions: VercelClientOptions,
     deploymentOptions: DeploymentOptions = {},
-    nowConfig: NowConfig = {}
+    nowConfig: VercelConfig = {}
   ): AsyncIterableIterator<{ type: DeploymentEventType; payload: any }> {
     const { path } = clientOptions;
 
@@ -74,12 +74,7 @@ export default function buildCreateDeployment() {
       debug(`Provided 'path' is a single file`);
     }
 
-    let { fileList } = await buildFileTree(
-      path,
-      clientOptions.isDirectory,
-      debug,
-      clientOptions.prebuilt
-    );
+    let { fileList } = await buildFileTree(path, clientOptions, debug);
 
     let configPath: string | undefined;
     if (!nowConfig) {
@@ -114,7 +109,11 @@ export default function buildCreateDeployment() {
       };
     }
 
-    const files = await hashes(fileList);
+    const hashedFileMap = await hashes(fileList);
+    const nftFileList = clientOptions.prebuilt
+      ? await resolveNftJsonFiles(hashedFileMap)
+      : [];
+    const files = await hashes(nftFileList, hashedFileMap);
 
     debug(`Yielding a 'hashes-calculated' event with ${files.size} hashes`);
     yield { type: 'hashes-calculated', payload: mapToObject(files) };

packages/client/src/types.ts

@@ -15,6 +15,7 @@ export interface VercelClientOptions {
   apiUrl?: string;
   force?: boolean;
   prebuilt?: boolean;
+  rootDirectory?: string;
   withCache?: boolean;
   userAgent?: string;
   defaultName?: string;

packages/client/src/utils/hashes.ts

@@ -1,6 +1,7 @@
 import { createHash } from 'crypto';
 import fs from 'fs-extra';
 import { Sema } from 'async-sema';
+import { join, dirname } from 'path';
 
 export interface DeploymentFile {
   names: string[];
@@ -15,9 +16,7 @@ export interface DeploymentFile {
  * @return {String} hex digest
  */
 function hash(buf: Buffer): string {
-  return createHash('sha1')
-    .update(buf)
-    .digest('hex');
+  return createHash('sha1').update(buf).digest('hex');
 }
 
 /**
@@ -39,34 +38,68 @@ export const mapToObject = (
 /**
  * Computes hashes for the contents of each file given.
  *
- * @param {Array} of {String} full paths
- * @return {Map}
+ * @param files - absolute file paths
+ * @param map - optional map of files to append
+ * @return Map of hash digest to file object
  */
-async function hashes(files: string[]): Promise<Map<string, DeploymentFile>> {
-  const map = new Map<string, DeploymentFile>();
+export async function hashes(
+  files: string[],
+  map = new Map<string, DeploymentFile>()
+): Promise<Map<string, DeploymentFile>> {
   const semaphore = new Sema(100);
 
   await Promise.all(
-    files.map(
-      async (name: string): Promise<void> => {
-        await semaphore.acquire();
-        const data = await fs.readFile(name);
-        const { mode } = await fs.stat(name);
+    files.map(async (name: string): Promise<void> => {
+      await semaphore.acquire();
+      const data = await fs.readFile(name);
+      const { mode } = await fs.stat(name);
 
-        const h = hash(data);
-        const entry = map.get(h);
+      const h = hash(data);
+      const entry = map.get(h);
 
-        if (entry) {
+      if (entry) {
+        if (entry.names[0] !== name) {
           entry.names.push(name);
-        } else {
-          map.set(h, { names: [name], data, mode });
         }
-
-        semaphore.release();
+      } else {
+        map.set(h, { names: [name], data, mode });
       }
-    )
+
+      semaphore.release();
+    })
   );
   return map;
 }
 
-export default hashes;
+export async function resolveNftJsonFiles(
+  hashedFiles: Map<string, DeploymentFile>
+): Promise<string[]> {
+  const semaphore = new Sema(100);
+  const existingFiles = Array.from(hashedFiles.values());
+  const resolvedFiles = new Set<string>();
+
+  await Promise.all(
+    existingFiles.map(async file => {
+      await semaphore.acquire();
+      const fsPath = file.names[0];
+      if (fsPath.endsWith('.nft.json')) {
+        const json = file.data.toString('utf8');
+        const { version, files } = JSON.parse(json) as {
+          version: number;
+          files: string[] | { input: string; output: string }[];
+        };
+        if (version === 1 || version === 2) {
+          for (let f of files) {
+            const relPath = typeof f === 'string' ? f : f.input;
+            resolvedFiles.add(join(dirname(fsPath), relPath));
+          }
+        } else {
+          console.error(`Invalid nft.json version: ${version}`);
+        }
+      }
+      semaphore.release();
+    })
+  );
+
+  return Array.from(resolvedFiles);
+}

packages/client/src/utils/index.ts

@@ -1,7 +1,7 @@
 import { DeploymentFile } from './hashes';
 import { FetchOptions } from '@zeit/fetch';
 import { nodeFetch, zeitFetch } from './fetch';
-import { join, sep, relative } from 'path';
+import { join, sep, relative, posix } from 'path';
 import { URL } from 'url';
 import ignore from 'ignore';
 type Ignore = ReturnType<typeof ignore>;
@@ -81,13 +81,16 @@ const maybeRead = async function <T>(path: string, default_: T) {
 
 export async function buildFileTree(
   path: string | string[],
-  isDirectory: boolean,
-  debug: Debug,
-  prebuilt?: boolean
+  {
+    isDirectory,
+    prebuilt,
+    rootDirectory,
+  }: Pick<VercelClientOptions, 'isDirectory' | 'prebuilt' | 'rootDirectory'>,
+  debug: Debug
 ): Promise<{ fileList: string[]; ignoreList: string[] }> {
   const ignoreList: string[] = [];
   let fileList: string[];
-  let { ig, ignores } = await getVercelIgnore(path, prebuilt);
+  let { ig, ignores } = await getVercelIgnore(path, prebuilt, rootDirectory);
 
   debug(`Found ${ignores.length} rules in .vercelignore`);
   debug('Building file tree...');
@@ -119,37 +122,50 @@ export async function buildFileTree(
 
 export async function getVercelIgnore(
   cwd: string | string[],
-  prebuilt?: boolean
+  prebuilt?: boolean,
+  rootDirectory?: string
 ): Promise<{ ig: Ignore; ignores: string[] }> {
-  const ignores: string[] = prebuilt
-    ? ['*', '!.output', '!.output/**']
-    : [
-        '.hg',
-        '.git',
-        '.gitmodules',
-        '.svn',
-        '.cache',
-        '.next',
-        '.now',
-        '.vercel',
-        '.npmignore',
-        '.dockerignore',
-        '.gitignore',
-        '.*.swp',
-        '.DS_Store',
-        '.wafpicke-*',
-        '.lock-wscript',
-        '.env.local',
-        '.env.*.local',
-        '.venv',
-        'npm-debug.log',
-        'config.gypi',
-        'node_modules',
-        '__pycache__',
-        'venv',
-        'CVS',
-        '.output',
-      ];
+  let ignores: string[] = [];
+
+  const outputDir = posix.join(rootDirectory || '', '.output');
+
+  if (prebuilt) {
+    ignores.push('*');
+    const parts = outputDir.split('/');
+    parts.forEach((_, i) => {
+      const level = parts.slice(0, i + 1).join('/');
+      ignores.push(`!${level}`);
+    });
+    ignores.push(`!${outputDir}/**`);
+  } else {
+    ignores = [
+      '.hg',
+      '.git',
+      '.gitmodules',
+      '.svn',
+      '.cache',
+      '.next',
+      '.now',
+      '.vercel',
+      '.npmignore',
+      '.dockerignore',
+      '.gitignore',
+      '.*.swp',
+      '.DS_Store',
+      '.wafpicke-*',
+      '.lock-wscript',
+      '.env.local',
+      '.env.*.local',
+      '.venv',
+      'npm-debug.log',
+      'config.gypi',
+      'node_modules',
+      '__pycache__',
+      'venv',
+      'CVS',
+      `.output`,
+    ];
+  }
   const cwds = Array.isArray(cwd) ? cwd : [cwd];
 
   const files = await Promise.all(
@@ -250,39 +266,31 @@ export const prepareFiles = (
   files: Map<string, DeploymentFile>,
   clientOptions: VercelClientOptions
 ): PreparedFile[] => {
-  const preparedFiles = [...files.keys()].reduce(
-    (acc: PreparedFile[], sha: string): PreparedFile[] => {
-      const next = [...acc];
+  const preparedFiles: PreparedFile[] = [];
+  for (const [sha, file] of files) {
+    for (const name of file.names) {
+      let fileName: string;
 
-      const file = files.get(sha) as DeploymentFile;
-
-      for (const name of file.names) {
-        let fileName: string;
-
-        if (clientOptions.isDirectory) {
-          // Directory
-          fileName =
-            typeof clientOptions.path === 'string'
-              ? relative(clientOptions.path, name)
-              : name;
-        } else {
-          // Array of files or single file
-          const segments = name.split(sep);
-          fileName = segments[segments.length - 1];
-        }
-
-        next.push({
-          file: isWin ? fileName.replace(/\\/g, '/') : fileName,
-          size: file.data.byteLength || file.data.length,
-          mode: file.mode,
-          sha,
-        });
+      if (clientOptions.isDirectory) {
+        // Directory
+        fileName =
+          typeof clientOptions.path === 'string'
+            ? relative(clientOptions.path, name)
+            : name;
+      } else {
+        // Array of files or single file
+        const segments = name.split(sep);
+        fileName = segments[segments.length - 1];
       }
 
-      return next;
-    },
-    []
-  );
+      preparedFiles.push({
+        file: isWin ? fileName.replace(/\\/g, '/') : fileName,
+        size: file.data.byteLength || file.data.length,
+        mode: file.mode,
+        sha,
+      });
+    }
+  }
 
   return preparedFiles;
 };

packages/client/tests/fixtures/file-system-api-root-directory/foo.txt

@@ -0,0 +1 @@
+foo

packages/client/tests/fixtures/file-system-api-root-directory/root/.output/baz.txt

@@ -0,0 +1 @@
+baz

packages/client/tests/fixtures/file-system-api-root-directory/root/.output/sub/qux.txt

@@ -0,0 +1 @@
+qux

packages/client/tests/fixtures/file-system-api-root-directory/root/bar.txt

@@ -0,0 +1 @@
+bar

packages/client/tests/fixtures/file-system-api-root-directory/someother/.output/baz.txt

@@ -0,0 +1 @@
+baz

packages/client/tests/fixtures/file-system-api-root-directory/someother/.output/sub/qux.txt

@@ -0,0 +1 @@
+qux

packages/client/tests/fixtures/file-system-api-root-directory/someother/bar.txt

@@ -0,0 +1 @@
+bar

packages/client/tests/fixtures/file-system-api/.output/baz.txt

@@ -0,0 +1 @@
+baz

packages/client/tests/fixtures/file-system-api/.output/sub/qux.txt

@@ -0,0 +1 @@
+qux

packages/client/tests/fixtures/file-system-api/foo.txt

@@ -0,0 +1 @@
+foo

packages/client/tests/fixtures/file-system-api/sub/bar.txt

@@ -0,0 +1 @@
+bar

packages/client/tests/tsconfig.json

@@ -0,0 +1,4 @@
+{
+  "extends": "../tsconfig.json",
+  "include": ["*.test.ts"]
+}

packages/client/tests/unit.utils.test.ts

@@ -17,7 +17,11 @@ const toAbsolutePaths = (cwd: string, files: string[]) =>
 describe('buildFileTree()', () => {
   it('should exclude files using `.nowignore` blocklist', async () => {
     const cwd = fixture('nowignore');
-    const { fileList, ignoreList } = await buildFileTree(cwd, true, noop);
+    const { fileList, ignoreList } = await buildFileTree(
+      cwd,
+      { isDirectory: true },
+      noop
+    );
 
     const expectedFileList = toAbsolutePaths(cwd, ['.nowignore', 'index.txt']);
     expect(normalizeWindowsPaths(expectedFileList).sort()).toEqual(
@@ -36,7 +40,11 @@ describe('buildFileTree()', () => {
 
   it('should include the node_modules using `.vercelignore` allowlist', async () => {
     const cwd = fixture('vercelignore-allow-nodemodules');
-    const { fileList, ignoreList } = await buildFileTree(cwd, true, noop);
+    const { fileList, ignoreList } = await buildFileTree(
+      cwd,
+      { isDirectory: true },
+      noop
+    );
 
     const expected = toAbsolutePaths(cwd, [
       'node_modules/one.txt',
@@ -54,4 +62,90 @@ describe('buildFileTree()', () => {
       normalizeWindowsPaths(ignoreList).sort()
     );
   });
+
+  it('should find root files but ignore .output files when prebuilt=false', async () => {
+    const cwd = fixture('file-system-api');
+    const { fileList, ignoreList } = await buildFileTree(
+      cwd,
+      { isDirectory: true, prebuilt: false },
+      noop
+    );
+
+    const expectedFileList = toAbsolutePaths(cwd, ['foo.txt', 'sub/bar.txt']);
+    expect(normalizeWindowsPaths(expectedFileList).sort()).toEqual(
+      normalizeWindowsPaths(fileList).sort()
+    );
+
+    const expectedIgnoreList = ['.output'];
+    expect(normalizeWindowsPaths(expectedIgnoreList).sort()).toEqual(
+      normalizeWindowsPaths(ignoreList).sort()
+    );
+  });
+
+  it('should find .output files but ignore other files when prebuilt=true', async () => {
+    const cwd = fixture('file-system-api');
+    const { fileList, ignoreList } = await buildFileTree(
+      cwd,
+      { isDirectory: true, prebuilt: true },
+      noop
+    );
+
+    const expectedFileList = toAbsolutePaths(cwd, [
+      '.output/baz.txt',
+      '.output/sub/qux.txt',
+    ]);
+    expect(normalizeWindowsPaths(expectedFileList).sort()).toEqual(
+      normalizeWindowsPaths(fileList).sort()
+    );
+
+    const expectedIgnoreList = ['foo.txt', 'sub'];
+    expect(normalizeWindowsPaths(expectedIgnoreList).sort()).toEqual(
+      normalizeWindowsPaths(ignoreList).sort()
+    );
+  });
+
+  it('should find root files but ignore all .output files when prebuilt=false and rootDirectory=root', async () => {
+    const cwd = fixture('file-system-api-root-directory');
+    const { fileList, ignoreList } = await buildFileTree(
+      cwd,
+      { isDirectory: true, prebuilt: false, rootDirectory: 'root' },
+      noop
+    );
+
+    const expectedFileList = toAbsolutePaths(cwd, [
+      'foo.txt',
+      'root/bar.txt',
+      'someother/bar.txt',
+    ]);
+    expect(normalizeWindowsPaths(expectedFileList).sort()).toEqual(
+      normalizeWindowsPaths(fileList).sort()
+    );
+
+    const expectedIgnoreList = ['root/.output', 'someother/.output'];
+    expect(normalizeWindowsPaths(expectedIgnoreList).sort()).toEqual(
+      normalizeWindowsPaths(ignoreList).sort()
+    );
+  });
+
+  it('should find root/.output files but ignore other files when prebuilt=true and rootDirectory=root', async () => {
+    const cwd = fixture('file-system-api-root-directory');
+    const { fileList, ignoreList } = await buildFileTree(
+      cwd,
+      { isDirectory: true, prebuilt: true, rootDirectory: 'root' },
+      noop
+    );
+
+    const expectedFileList = toAbsolutePaths(cwd, [
+      'root/.output/baz.txt',
+      'root/.output/sub/qux.txt',
+    ]);
+    expect(normalizeWindowsPaths(expectedFileList).sort()).toEqual(
+      normalizeWindowsPaths(fileList).sort()
+    );
+
+    const expectedIgnoreList = ['foo.txt', 'root/bar.txt', 'someother'];
+    expect(normalizeWindowsPaths(expectedIgnoreList).sort()).toEqual(
+      normalizeWindowsPaths(ignoreList).sort()
+    );
+  });
 });

packages/frameworks/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/frameworks",
-  "version": "0.5.1-canary.16",
+  "version": "0.5.1-canary.17",
   "main": "./dist/frameworks.js",
   "types": "./dist/frameworks.d.ts",
   "files": [

packages/frameworks/src/frameworks.ts

@@ -141,7 +141,6 @@ export const frameworks = [
     },
     dependency: 'gatsby',
     getOutputDirName: async () => 'public',
-    getFsOutputDir: async () => 'public',
     defaultRoutes: async (dirPrefix: string) => {
       // This file could be generated by gatsby-plugin-now or gatsby-plugin-zeit-now
       try {
@@ -226,7 +225,6 @@ export const frameworks = [
       },
     },
     dependency: 'remix',
-    getFsOutputDir: async () => 'public',
     getOutputDirName: async () => 'public',
     defaultRoutes: [
       {
@@ -254,10 +252,13 @@ export const frameworks = [
         source: '/build/(.*)',
         regex: '/build/(.*)',
         headers: [
-          { key: 'cache-control', value: 'public, max-age=31536000, immutable' },
+          {
+            key: 'cache-control',
+            value: 'public, max-age=31536000, immutable',
+          },
         ],
       },
-    ]
+    ],
   },
   {
     name: 'Hexo',
@@ -294,7 +295,6 @@ export const frameworks = [
       },
     },
     dependency: 'hexo',
-    getFsOutputDir: async () => 'public',
     getOutputDirName: async () => 'public',
   },
   {
@@ -332,7 +332,6 @@ export const frameworks = [
       },
     },
     dependency: '@11ty/eleventy',
-    getFsOutputDir: async () => '_site',
     getOutputDirName: async () => '_site',
     cachePattern: '.cache/**',
   },
@@ -372,22 +371,6 @@ export const frameworks = [
       },
     },
     dependency: '@docusaurus/core',
-    getFsOutputDir: async (dirPrefix: string) => {
-      const base = 'build';
-      try {
-        const location = join(dirPrefix, base);
-        const content = await readdir(location, { withFileTypes: true });
-
-        // If there is only one file in it that is a dir we'll use it as dist dir
-        if (content.length === 1 && content[0].isDirectory()) {
-          return join(base, content[0].name);
-        }
-      } catch (error) {
-        console.error(`Error detecting output directory: `, error);
-      }
-
-      return base;
-    },
     getOutputDirName: async (dirPrefix: string) => {
       const base = 'build';
       try {
@@ -527,21 +510,6 @@ export const frameworks = [
       },
     },
     dependency: 'docusaurus',
-    getFsOutputDir: async (dirPrefix: string) => {
-      const base = 'build';
-      try {
-        const location = join(dirPrefix, base);
-        const content = await readdir(location, { withFileTypes: true });
-
-        // If there is only one file in it that is a dir we'll use it as dist dir
-        if (content.length === 1 && content[0].isDirectory()) {
-          return join(base, content[0].name);
-        }
-      } catch (error) {
-        console.error(`Error detecting output directory: `, error);
-      }
-      return base;
-    },
     getOutputDirName: async (dirPrefix: string) => {
       const base = 'build';
       try {
@@ -593,7 +561,6 @@ export const frameworks = [
       },
     },
     dependency: 'preact-cli',
-    getFsOutputDir: async () => 'build',
     getOutputDirName: async () => 'build',
     defaultRoutes: [
       {
@@ -650,7 +617,6 @@ export const frameworks = [
       },
     },
     dependency: '@dojo/cli',
-    getFsOutputDir: async () => 'output/dist',
     getOutputDirName: async () => join('output', 'dist'),
     defaultRoutes: [
       {
@@ -717,7 +683,6 @@ export const frameworks = [
       },
     },
     dependency: 'ember-cli',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async () => 'dist',
     defaultRoutes: [
       {
@@ -772,7 +737,6 @@ export const frameworks = [
       },
     },
     dependency: '@vue/cli-service',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async () => 'dist',
     defaultRoutes: [
       {
@@ -849,7 +813,6 @@ export const frameworks = [
       },
     },
     dependency: '@scullyio/init',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async () => 'dist/static',
   },
   {
@@ -886,7 +849,6 @@ export const frameworks = [
       },
     },
     dependency: '@ionic/angular',
-    getFsOutputDir: async () => 'www',
     getOutputDirName: async () => 'www',
     defaultRoutes: [
       {
@@ -940,7 +902,6 @@ export const frameworks = [
       },
     },
     dependency: '@angular/cli',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async (dirPrefix: string) => {
       const base = 'dist';
       try {
@@ -1008,7 +969,6 @@ export const frameworks = [
       },
     },
     dependency: 'polymer-cli',
-    getFsOutputDir: async () => 'build',
     getOutputDirName: async (dirPrefix: string) => {
       const base = 'build';
       try {
@@ -1078,7 +1038,6 @@ export const frameworks = [
       },
     },
     dependency: 'sirv-cli',
-    getFsOutputDir: async () => 'public',
     getOutputDirName: async () => 'public',
     defaultRoutes: [
       {
@@ -1128,10 +1087,9 @@ export const frameworks = [
         placeholder: 'svelte-kit dev',
       },
       outputDirectory: {
-        placeholder: 'public',
+        value: 'public',
       },
     },
-    getFsOutputDir: async () => '.output',
     getOutputDirName: async () => 'public',
   },
   {
@@ -1168,7 +1126,6 @@ export const frameworks = [
       },
     },
     dependency: '@ionic/react',
-    getFsOutputDir: async () => 'build',
     getOutputDirName: async () => 'build',
     defaultRoutes: [
       {
@@ -1276,7 +1233,6 @@ export const frameworks = [
       },
     },
     dependency: 'react-scripts',
-    getFsOutputDir: async () => 'build',
     getOutputDirName: async () => 'build',
     defaultRoutes: [
       {
@@ -1378,7 +1334,6 @@ export const frameworks = [
       },
     },
     dependency: 'gridsome',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async () => 'dist',
   },
   {
@@ -1416,7 +1371,6 @@ export const frameworks = [
       },
     },
     dependency: 'umi',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async () => 'dist',
     defaultRoutes: [
       {
@@ -1470,7 +1424,6 @@ export const frameworks = [
       },
     },
     dependency: 'sapper',
-    getFsOutputDir: async () => '__sapper__/export',
     getOutputDirName: async () => '__sapper__/export',
   },
   {
@@ -1508,7 +1461,6 @@ export const frameworks = [
       },
     },
     dependency: 'saber',
-    getFsOutputDir: async () => 'public',
     getOutputDirName: async () => 'public',
     defaultRoutes: [
       {
@@ -1577,7 +1529,6 @@ export const frameworks = [
       },
     },
     dependency: '@stencil/core',
-    getFsOutputDir: async () => 'www',
     getOutputDirName: async () => 'www',
     defaultRoutes: [
       {
@@ -1666,7 +1617,6 @@ export const frameworks = [
       },
     },
     dependency: 'nuxt',
-    getFsOutputDir: async () => '.output',
     getOutputDirName: async () => 'dist',
     cachePattern: '.nuxt/**',
     defaultRoutes: [
@@ -1724,7 +1674,6 @@ export const frameworks = [
         placeholder: 'RedwoodJS default',
       },
     },
-    getFsOutputDir: async () => 'public',
     getOutputDirName: async () => 'public',
   },
   {
@@ -1768,16 +1717,6 @@ export const frameworks = [
         placeholder: '`public` or `publishDir` from the `config` file',
       },
     },
-    getFsOutputDir: async (dirPrefix: string): Promise<string> => {
-      type HugoConfig = { publishDir?: string };
-      const config = await readConfigFile<HugoConfig>(
-        ['config.json', 'config.yaml', 'config.toml'].map(fileName => {
-          return join(dirPrefix, fileName);
-        })
-      );
-
-      return (config && config.publishDir) || 'public';
-    },
     getOutputDirName: async (dirPrefix: string): Promise<string> => {
       type HugoConfig = { publishDir?: string };
       const config = await readConfigFile<HugoConfig>(
@@ -1822,13 +1761,6 @@ export const frameworks = [
         placeholder: '`_site` or `destination` from `_config.yml`',
       },
     },
-    getFsOutputDir: async (dirPrefix: string): Promise<string> => {
-      type JekyllConfig = { destination?: string };
-      const config = await readConfigFile<JekyllConfig>(
-        join(dirPrefix, '_config.yml')
-      );
-      return (config && config.destination) || '_site';
-    },
     getOutputDirName: async (dirPrefix: string): Promise<string> => {
       type JekyllConfig = { destination?: string };
       const config = await readConfigFile<JekyllConfig>(
@@ -1870,7 +1802,6 @@ export const frameworks = [
         value: 'public',
       },
     },
-    getFsOutputDir: async () => 'public',
     getOutputDirName: async () => 'public',
   },
   {
@@ -1905,7 +1836,6 @@ export const frameworks = [
         value: 'build',
       },
     },
-    getFsOutputDir: async () => 'build',
     getOutputDirName: async () => 'build',
     cachePattern: '{vendor/bin,vendor/cache,vendor/bundle}/**',
   },
@@ -1940,7 +1870,6 @@ export const frameworks = [
         value: 'public',
       },
     },
-    getFsOutputDir: async () => 'public',
     getOutputDirName: async () => 'public',
     defaultVersion: '0.13.0',
   },
@@ -1980,7 +1909,6 @@ export const frameworks = [
       },
     },
     dependency: 'vite',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async () => 'dist',
   },
   {
@@ -2018,7 +1946,6 @@ export const frameworks = [
       },
     },
     dependency: 'parcel',
-    getFsOutputDir: async () => 'dist',
     getOutputDirName: async () => 'dist',
     defaultRoutes: [
       {

packages/frameworks/src/types.ts

@@ -162,9 +162,9 @@ export interface Framework {
   dependency?: string;
   /**
    * Function that returns the name of the directory that the framework outputs
-   * its build results to. In some cases this is read from a configuration file.
+   * its File System API build results to, usually called `.output`.
    */
-  getFsOutputDir: (dirPrefix: string) => Promise<string>;
+  getFsOutputDir?: (dirPrefix: string) => Promise<string>;
   /**
    * Function that returns the name of the directory that the framework outputs
    * its STATIC build results to. In some cases this is read from a configuration file.

packages/middleware/package.json

@@ -1,6 +1,6 @@
 {
   "name": "vercel-plugin-middleware",
-  "version": "0.0.0-canary.7",
+  "version": "0.0.0-canary.19",
   "license": "MIT",
   "main": "./dist/index",
   "homepage": "",
@@ -30,6 +30,7 @@
     "@types/node-fetch": "^2",
     "@types/ua-parser-js": "0.7.36",
     "@types/uuid": "8.3.1",
+    "@vercel/build-utils": "2.12.3-canary.42",
     "@vercel/ncc": "0.24.0",
     "cookie": "0.4.1",
     "formdata-node": "4.3.1",

packages/middleware/src/entries.js

@@ -1,4 +1,4 @@
-import * as middleware from './_middleware';
+import * as middleware from './_temp_middleware';
 _ENTRIES = typeof _ENTRIES === 'undefined' ? {} : _ENTRIES;
 _ENTRIES['middleware_pages/_middleware'] = {
   default: async function (ev) {

packages/middleware/src/esbuild-plugins.ts

@@ -0,0 +1,52 @@
+import path from 'path';
+import * as esbuild from 'esbuild';
+
+const processInjectFile = `
+// envOverride is passed by esbuild plugin
+const env = envOverride
+function cwd() {
+    return '/'
+}
+function chdir(dir) {
+    throw new Error('process.chdir is not supported')
+}
+export const process = {
+  argv: [],
+  env,
+  chdir,
+  cwd,
+};
+`;
+
+export function nodeProcessPolyfillPlugin({ env = {} } = {}): esbuild.Plugin {
+  return {
+    name: 'node-process-polyfill',
+    setup({ initialOptions, onResolve, onLoad }) {
+      onResolve({ filter: /_virtual-process-polyfill_\.js/ }, ({ path }) => {
+        return {
+          path,
+          sideEffects: false,
+        };
+      });
+
+      onLoad({ filter: /_virtual-process-polyfill_\.js/ }, () => {
+        const contents = `const envOverride = ${JSON.stringify(
+          env
+        )};\n${processInjectFile}`;
+        return {
+          loader: 'js',
+          contents,
+        };
+      });
+
+      const polyfills = [
+        path.resolve(__dirname, '_virtual-process-polyfill_.js'),
+      ];
+      if (initialOptions.inject) {
+        initialOptions.inject.push(...polyfills);
+      } else {
+        initialOptions.inject = [...polyfills];
+      }
+    },
+  };
+}

packages/middleware/src/index.ts

@@ -5,6 +5,7 @@ import { promises as fsp } from 'fs';
 import { IncomingMessage, ServerResponse } from 'http';
 import libGlob from 'glob';
 import Proxy from 'http-proxy';
+import { updateFunctionsManifest } from '@vercel/build-utils';
 
 import { run } from './websandbox';
 import type { FetchEventResult } from './websandbox/types';
@@ -16,13 +17,15 @@ import {
   UrlWithParsedQuery,
 } from 'url';
 import { toNodeHeaders } from './websandbox/utils';
+import { nodeProcessPolyfillPlugin } from './esbuild-plugins';
 
 const glob = util.promisify(libGlob);
 const SUPPORTED_EXTENSIONS = ['.js', '.ts'];
 
 // File name of the `entries.js` file that gets copied into the
 // project directory. Use a name that is unlikely to conflict.
-const ENTRIES_NAME = '___vc_entries.js';
+const TMP_ENTRIES_NAME = '.output/inputs/middleware/___vc_entries.js';
+const TMP_MIDDLEWARE_BUNDLE = '.output/inputs/middleware/_temp_middleware.js';
 
 async function getMiddlewareFile(workingDirectory: string) {
   // Only the root-level `_middleware.*` files are considered.
@@ -52,17 +55,37 @@ async function getMiddlewareFile(workingDirectory: string) {
 }
 
 export async function build({ workPath }: { workPath: string }) {
-  const entriesPath = join(workPath, ENTRIES_NAME);
+  const entriesPath = join(workPath, TMP_ENTRIES_NAME);
+  const transientFilePath = join(workPath, TMP_MIDDLEWARE_BUNDLE);
   const middlewareFile = await getMiddlewareFile(workPath);
   if (!middlewareFile) return;
 
   console.log('Compiling middleware file: %j', middlewareFile);
 
-  // Create `_ENTRIES` wrapper
-  await fsp.copyFile(join(__dirname, 'entries.js'), entriesPath);
-
-  // Build
+  /**
+   * Two builds happen here, because esbuild doesn't offer a way to add a banner
+   * to individual input files, and the entries wrapper relies on running in
+   * non-strict mode to access the ENTRIES global.
+   *
+   * To work around this, we bundle the middleware directly and add
+   * 'use strict'; to make the entire bundle run in strict mode. We then bundle
+   * a second time, adding the global ENTRIES wrapper and preserving the
+   * 'use strict' for the entire scope of the original bundle.
+   */
   try {
+    await esbuild.build({
+      entryPoints: [middlewareFile],
+      bundle: true,
+      absWorkingDir: workPath,
+      outfile: transientFilePath,
+      banner: {
+        js: '"use strict";',
+      },
+      plugins: [nodeProcessPolyfillPlugin({ env: process.env })],
+      format: 'cjs',
+    });
+    // Create `_ENTRIES` wrapper
+    await fsp.copyFile(join(__dirname, 'entries.js'), entriesPath);
     await esbuild.build({
       entryPoints: [entriesPath],
       bundle: true,
@@ -70,29 +93,24 @@ export async function build({ workPath }: { workPath: string }) {
       outfile: join(workPath, '.output/server/pages/_middleware.js'),
     });
   } finally {
+    await fsp.unlink(transientFilePath);
     await fsp.unlink(entriesPath);
   }
 
-  // Write middleware manifest
-  const middlewareManifest = {
-    version: 1,
-    sortedMiddleware: ['/'],
-    middleware: {
-      '/': {
-        env: [],
-        files: ['server/pages/_middleware.js'],
-        name: 'pages/_middleware',
-        page: '/',
-        regexp: '^/.*$',
-      },
-    },
+  const fileName = basename(middlewareFile);
+  const pages: { [key: string]: any } = {};
+
+  pages[fileName] = {
+    runtime: 'web',
+    env: [],
+    files: ['server/pages/_middleware.js'],
+    name: 'pages/_middleware',
+    page: '/',
+    regexp: '^/.*$',
+    sortingIndex: 1,
   };
-  const middlewareManifestData = JSON.stringify(middlewareManifest, null, 2);
-  const middlewareManifestPath = join(
-    workPath,
-    '.output/server/middleware-manifest.json'
-  );
-  await fsp.writeFile(middlewareManifestPath, middlewareManifestData);
+
+  await updateFunctionsManifest({ workPath, pages });
 }
 
 const stringifyQuery = (req: IncomingMessage, query: ParsedUrlQuery) => {

packages/middleware/src/websandbox/sandbox/sandbox.ts

@@ -114,6 +114,7 @@ export async function run(params: {
     const content = readFileSync(params.path, 'utf-8');
     const esBuildResult = esbuild.transformSync(content, {
       format: 'cjs',
+      banner: '"use strict";',
     });
     const x = vm.runInNewContext(m.wrap(esBuildResult.code), cache.sandbox, {
       filename: params.path,
@@ -163,6 +164,7 @@ function sandboxRequire(referrer: string, specifier: string) {
 
   const transformOptions: esbuild.TransformOptions = {
     format: 'cjs',
+    banner: '"use strict";',
   };
   if (extname(resolved) === '.json') {
     transformOptions.loader = 'json';

packages/middleware/test/__snapshots__/build.test.ts.snap

@@ -2,8 +2,8 @@
 
 exports[`build() should build simple middleware 1`] = `
 Object {
-  "middleware": Object {
-    "/": Object {
+  "pages": Object {
+    "_middleware.js": Object {
       "env": Array [],
       "files": Array [
         "server/pages/_middleware.js",
@@ -11,11 +11,10 @@ Object {
       "name": "pages/_middleware",
       "page": "/",
       "regexp": "^/.*$",
+      "runtime": "web",
+      "sortingIndex": 1,
     },
   },
-  "sortedMiddleware": Array [
-    "/",
-  ],
-  "version": 1,
+  "version": 2,
 }
 `;

packages/middleware/test/build.test.ts

@@ -3,6 +3,30 @@ import { promises as fsp } from 'fs';
 import { build } from '../src';
 import { Response } from 'node-fetch';
 
+const setupFixture = async (fixture: string) => {
+  const fixturePath = join(__dirname, `fixtures/${fixture}`);
+  await build({
+    workPath: fixturePath,
+  });
+
+  const functionsManifest = JSON.parse(
+    await fsp.readFile(
+      join(fixturePath, '.output/functions-manifest.json'),
+      'utf8'
+    )
+  );
+
+  const outputFile = join(fixturePath, '.output/server/pages/_middleware.js');
+  expect(await fsp.stat(outputFile)).toBeTruthy();
+  require(outputFile);
+  //@ts-ignore
+  const middleware = global._ENTRIES['middleware_pages/_middleware'].default;
+  return {
+    middleware,
+    functionsManifest,
+  };
+};
+
 describe('build()', () => {
   beforeEach(() => {
     //@ts-ignore
@@ -15,25 +39,9 @@ describe('build()', () => {
     delete global._ENTRIES;
   });
   it('should build simple middleware', async () => {
-    const fixture = join(__dirname, 'fixtures/simple');
-    await build({
-      workPath: fixture,
-    });
+    const { functionsManifest, middleware } = await setupFixture('simple');
 
-    const middlewareManifest = JSON.parse(
-      await fsp.readFile(
-        join(fixture, '.output/server/middleware-manifest.json'),
-        'utf8'
-      )
-    );
-    expect(middlewareManifest).toMatchSnapshot();
-
-    const outputFile = join(fixture, '.output/server/pages/_middleware.js');
-    expect(await fsp.stat(outputFile)).toBeTruthy();
-
-    require(outputFile);
-    //@ts-ignore
-    const middleware = global._ENTRIES['middleware_pages/_middleware'].default;
+    expect(functionsManifest).toMatchSnapshot();
     expect(typeof middleware).toStrictEqual('function');
     const handledResponse = await middleware({
       request: {
@@ -54,4 +62,38 @@ describe('build()', () => {
       (unhandledResponse.response as Response).headers.get('x-middleware-next')
     ).toEqual('1');
   });
+
+  it('should build simple middleware with env vars', async () => {
+    const expectedEnvVar = 'expected-env-var';
+    const fixture = join(__dirname, 'fixtures/env');
+    process.env.ENV_VAR_SHOULD_BE_DEFINED = expectedEnvVar;
+    await build({
+      workPath: fixture,
+    });
+    // env var should be inlined in the output
+    delete process.env.ENV_VAR_SHOULD_BE_DEFINED;
+
+    const outputFile = join(fixture, '.output/server/pages/_middleware.js');
+    expect(await fsp.stat(outputFile)).toBeTruthy();
+
+    require(outputFile);
+    //@ts-ignore
+    const middleware = global._ENTRIES['middleware_pages/_middleware'].default;
+    expect(typeof middleware).toStrictEqual('function');
+    const handledResponse = await middleware({
+      request: {},
+    });
+    expect(String(handledResponse.response.body)).toEqual(expectedEnvVar);
+    expect(
+      (handledResponse.response as Response).headers.get('x-middleware-next')
+    ).toEqual(null);
+  });
+
+  it('should create a middleware that runs in strict mode', async () => {
+    const { middleware } = await setupFixture('use-strict');
+    const response = await middleware({
+      request: {},
+    });
+    expect(String(response.response.body)).toEqual('is strict mode? yes');
+  });
 });

packages/middleware/test/fixtures/env/_middleware.js

@@ -0,0 +1,3 @@
+export default req => {
+  return new Response(process.env.ENV_VAR_SHOULD_BE_DEFINED);
+};

packages/middleware/test/fixtures/use-strict/_middleware.js

@@ -0,0 +1,6 @@
+export default function (req) {
+  const isStrict = (function () {
+    return !this;
+  })();
+  return new Response('is strict mode? ' + (isStrict ? 'yes' : 'no'));
+}

packages/plugin-go/package.json

@@ -1,7 +1,7 @@
 {
   "private": false,
   "name": "vercel-plugin-go",
-  "version": "1.0.0-canary.19",
+  "version": "1.0.0-canary.30",
   "main": "dist/index.js",
   "license": "MIT",
   "files": [
@@ -17,7 +17,7 @@
     "prepublishOnly": "tsc"
   },
   "dependencies": {
-    "@vercel/build-utils": "2.12.3-canary.31",
+    "@vercel/build-utils": "2.12.3-canary.42",
     "@vercel/go": "1.2.4-canary.4"
   },
   "devDependencies": {

packages/plugin-node/package.json

@@ -1,6 +1,6 @@
 {
   "name": "vercel-plugin-node",
-  "version": "1.12.2-canary.23",
+  "version": "1.12.2-canary.34",
   "license": "MIT",
   "main": "./dist/index",
   "homepage": "https://vercel.com/docs/runtimes#official-runtimes/node-js",
@@ -34,7 +34,7 @@
     "@types/node-fetch": "2",
     "@types/test-listen": "1.1.0",
     "@types/yazl": "2.4.2",
-    "@vercel/build-utils": "2.12.3-canary.31",
+    "@vercel/build-utils": "2.12.3-canary.42",
     "@vercel/fun": "1.0.3",
     "@vercel/ncc": "0.24.0",
     "@vercel/nft": "0.14.0",

packages/plugin-python/package.json

@@ -1,7 +1,7 @@
 {
   "private": false,
   "name": "vercel-plugin-python",
-  "version": "1.0.0-canary.20",
+  "version": "1.0.0-canary.31",
   "main": "dist/index.js",
   "license": "MIT",
   "files": [
@@ -17,8 +17,8 @@
     "prepublishOnly": "tsc"
   },
   "dependencies": {
-    "@vercel/build-utils": "2.12.3-canary.31",
-    "@vercel/python": "2.1.2-canary.1"
+    "@vercel/build-utils": "2.12.3-canary.42",
+    "@vercel/python": "2.1.2-canary.2"
   },
   "devDependencies": {
     "@types/node": "*",

packages/plugin-ruby/package.json

@@ -1,7 +1,7 @@
 {
   "private": false,
   "name": "vercel-plugin-ruby",
-  "version": "1.0.0-canary.18",
+  "version": "1.0.0-canary.30",
   "main": "dist/index.js",
   "license": "MIT",
   "files": [
@@ -17,8 +17,8 @@
     "prepublishOnly": "tsc"
   },
   "dependencies": {
-    "@vercel/build-utils": "2.12.3-canary.31",
-    "@vercel/ruby": "1.2.8-canary.6"
+    "@vercel/build-utils": "2.12.3-canary.42",
+    "@vercel/ruby": "1.2.10-canary.0"
   },
   "devDependencies": {
     "@types/node": "*",

packages/python/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vercel/python",
-  "version": "2.1.2-canary.1",
+  "version": "2.1.2-canary.2",
   "main": "./dist/index.js",
   "license": "MIT",
   "homepage": "https://vercel.com/docs/runtimes#official-runtimes/python",

packages/python/src/install.ts

@@ -1,4 +1,3 @@
-import { relative, basename } from 'path';
 import execa from 'execa';
 import { Meta, debug } from '@vercel/build-utils';
 
@@ -136,17 +135,10 @@ export async function installRequirementsFile({
   meta,
   args = [],
 }: InstallRequirementsFileArg) {
-  const fileAtRoot = relative(workPath, filePath) === basename(filePath);
-
-  // If the `requirements.txt` file is located in the Root Directory of the project and
-  // the new File System API is used (`avoidTopLevelInstall`), the Install Command
-  // will have already installed its dependencies, so we don't need to do it again.
-  if (meta.avoidTopLevelInstall && fileAtRoot) {
-    debug(
-      `Skipping requirements file installation, already installed by Install Command`
-    );
-    return;
-  }
+  // The Vercel platform already handles `requirements.txt` for frontend projects,
+  // but the installation logic there is different, because it seems to install all
+  // of the dependencies globally, whereas, for this Runtime, we want it to happen only
+  // locally, so we'll run a separate installation.
 
   if (
     meta.isDev &&

packages/ruby/install-ruby.ts

@@ -9,13 +9,24 @@ interface RubyVersion extends NodeVersion {
 
 const allOptions: RubyVersion[] = [
   { major: 2, minor: 7, range: '2.7.x', runtime: 'ruby2.7' },
-  { major: 2, minor: 5, range: '2.5.x', runtime: 'ruby2.5' },
+  {
+    major: 2,
+    minor: 5,
+    range: '2.5.x',
+    runtime: 'ruby2.5',
+    discontinueDate: new Date('2021-11-30'),
+  },
 ];
 
 function getLatestRubyVersion(): RubyVersion {
   return allOptions[0];
 }
 
+function isDiscontinued({ discontinueDate }: RubyVersion): boolean {
+  const today = Date.now();
+  return discontinueDate !== undefined && discontinueDate.getTime() <= today;
+}
+
 function getRubyPath(meta: Meta, gemfileContents: string) {
   let selection = getLatestRubyVersion();
   if (meta.isDev) {
@@ -37,8 +48,20 @@ function getRubyPath(meta: Meta, gemfileContents: string) {
       if (!found) {
         throw new NowBuildError({
           code: 'RUBY_INVALID_VERSION',
-          message: 'Found `Gemfile` with invalid Ruby version: `' + line + '`.',
-          link: 'https://vercel.com/docs/runtimes#official-runtimes/ruby/ruby-version',
+          message: `Found \`Gemfile\` with invalid Ruby version: \`${line}.\``,
+          link: 'http://vercel.link/ruby-version',
+        });
+      }
+      if (isDiscontinued(selection)) {
+        const latest = getLatestRubyVersion();
+        const intro = `Found \`Gemfile\` with discontinued Ruby version: \`${line}.\``;
+        const hint = `Please set \`ruby "~> ${latest.range}"\` in your \`Gemfile\` to use Ruby ${latest.range}.`;
+        const upstream =
+          'This change is the result of a decision made by an upstream infrastructure provider (AWS).';
+        throw new NowBuildError({
+          code: 'RUBY_DISCONTINUED_VERSION',
+          link: 'http://vercel.link/ruby-version',
+          message: `${intro} ${hint} ${upstream}`,
         });
       }
     }

packages/ruby/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@vercel/ruby",
   "author": "Nathan Cahill <nathan@nathancahill.com>",
-  "version": "1.2.8-canary.6",
+  "version": "1.2.10-canary.0",
   "license": "MIT",
   "main": "./dist/index",
   "homepage": "https://vercel.com/docs/runtimes#official-runtimes/ruby",

packages/ruby/test/fixtures/02-cowsay-vendored/now.json

@@ -1,6 +1,5 @@
 {
   "version": 2,
   "builds": [{ "src": "index.rb", "use": "@vercel/ruby" }],
-  "build": { "env": { "RUBY_VERSION": "2.7.x" } },
   "probes": [{ "path": "/", "mustContain": "gem:RANDOMNESS_PLACEHOLDER" }]
 }

packages/ruby/test/fixtures/04-cowsay-vendored-nested/now.json

@@ -1,7 +1,6 @@
 {
   "version": 2,
   "builds": [{ "src": "project/index.rb", "use": "@vercel/ruby" }],
-  "build": { "env": { "RUBY_VERSION": "2.7.x" } },
   "probes": [
     { "path": "/project/", "mustContain": "gem:RANDOMNESS_PLACEHOLDER" }
   ]

packages/ruby/test/fixtures/05-sinatra/now.json

@@ -1,6 +1,5 @@
 {
   "version": 2,
   "builds": [{ "src": "index.ru", "use": "@vercel/ruby" }],
-  "build": { "env": { "RUBY_VERSION": "2.7.x" } },
   "probes": [{ "path": "/", "mustContain": "gem:RANDOMNESS_PLACEHOLDER" }]
 }

packages/ruby/test/fixtures/11-version-2-5-error/Gemfile

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+ruby "~> 2.5.x"
+
+gem "cowsay", "~> 0.3.0"

packages/ruby/test/fixtures/11-version-2-5-error/Gemfile.lock

@@ -0,0 +1,16 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    cowsay (0.3.0)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  cowsay (~> 0.3.0)
+
+RUBY VERSION
+   ruby 2.5.5p157
+
+BUNDLED WITH
+   2.2.22

packages/ruby/test/fixtures/11-version-2-5-error/index.rb

@@ -0,0 +1,9 @@
+require 'cowsay'
+
+Handler = Proc.new do |req, res|
+  name = req.query['name'] || 'World'
+
+  res.status = 200
+  res['Content-Type'] = 'text/text; charset=utf-8'
+  res.body = Cowsay.say("Hello #{name}", 'cow')
+end

packages/ruby/test/fixtures/11-version-2-5-error/vercel.json

@@ -0,0 +1,4 @@
+{
+  "version": 2,
+  "builds": [{ "src": "index.rb", "use": "@vercel/ruby" }]
+}

packages/ruby/test/test.js

@@ -23,8 +23,32 @@ beforeAll(async () => {
 
 const fixturesPath = path.resolve(__dirname, 'fixtures');
 
+const testsThatFailToBuild = new Map([
+  [
+    '11-version-2-5-error',
+    'Found `Gemfile` with discontinued Ruby version: `ruby "~> 2.5.x".` Please set `ruby "~> 2.7.x"` in your `Gemfile` to use Ruby 2.7.x. This change is the result of a decision made by an upstream infrastructure provider (AWS).',
+  ],
+]);
+
 // eslint-disable-next-line no-restricted-syntax
 for (const fixture of fs.readdirSync(fixturesPath)) {
+  const errMsg = testsThatFailToBuild.get(fixture);
+  if (errMsg) {
+    // eslint-disable-next-line no-loop-func
+    it(`should fail to build ${fixture}`, async () => {
+      try {
+        await testDeployment(
+          { builderUrl, buildUtilsUrl },
+          path.join(fixturesPath, fixture)
+        );
+      } catch (err) {
+        expect(err).toBeTruthy();
+        expect(err.deployment).toBeTruthy();
+        expect(err.deployment.errorMessage).toBe(errMsg);
+      }
+    });
+    continue; //eslint-disable-line
+  }
   // eslint-disable-next-line no-loop-func
   it(`should build ${fixture}`, async () => {
     await expect(