Added file watcher to now dev

@types/nsfw/index.d.ts

@@ -0,0 +1,50 @@
+declare function nsfw(
+  dir: string,
+  callback: nsfw.EventsCallback,
+  options?: nsfw.WatcherOptions
+): Promise<nsfw.Watcher>;
+
+declare namespace nsfw {
+  export class Watcher {
+    start(): Promise<void>;
+    stop(): Promise<void>;
+  }
+  export interface BaseEvent {
+    action: number;
+    directory: string;
+  };
+  export interface CreatedEvent extends BaseEvent {
+    action: nsfw.actions.CREATED;
+    file: string;
+  }
+  export interface DeletedEvent extends BaseEvent {
+    action: nsfw.actions.DELETED;
+    file: string;
+  }
+  export interface ModifiedEvent extends BaseEvent {
+    action: nsfw.actions.MODIFIED;
+    file: string;
+  }
+  export interface RenamedEvent extends BaseEvent {
+    action: nsfw.actions.RENAMED;
+    oldFile: string;
+    newDirectory: string;
+    newFile: string;
+  }
+  export type Event = CreatedEvent | DeletedEvent | ModifiedEvent | RenamedEvent;
+  export type EventsCallback = (events: Event[]) => void;
+  export interface WatcherOptions {
+    debouceMS?: number;
+    errorCallback?(errors: Error[]);
+  };
+  export enum actions {
+    CREATED,
+    DELETED,
+    MODIFIED,
+    RENAMED
+  };
+}
+
+declare module 'nsfw' {
+  export = nsfw;
+}

package.json

@@ -169,6 +169,7 @@
     "ms": "2.1.1",
     "node-fetch": "1.7.3",
     "npm-package-arg": "6.1.0",
+    "nsfw": "1.2.2",
     "nyc": "13.2.0",
     "ora": "1.3.0",
     "pcre-to-regexp": "0.0.5",

src/commands/dev/lib/dev-builder.ts

@@ -202,6 +202,8 @@ export async function getBuildMatches(
       // of Now deployments.
       src = src.substring(1);
     }
+
+    // TODO: use the `files` map from DevServer instead of hitting the filesystem
     const entries = Object.values(await collectProjectFiles(src, cwd));
 
     for (const fileRef of entries) {

src/commands/dev/lib/dev-server.ts

@@ -1,6 +1,7 @@
 import ms from 'ms';
 import url from 'url';
 import http from 'http';
+import nsfw from 'nsfw';
 import fs from 'fs-extra';
 import chalk from 'chalk';
 import rawBody from 'raw-body';
@@ -10,6 +11,7 @@ import minimatch from 'minimatch';
 import httpProxy from 'http-proxy';
 import { randomBytes } from 'crypto';
 import serveHandler from 'serve-handler';
+import { FileFsRef } from '@now/build-utils';
 import { parse as parseDotenv } from 'dotenv';
 import { lookup as lookupMimeType } from 'mime-types';
 import { basename, dirname, extname, join, relative } from 'path';
@@ -47,31 +49,99 @@ export default class DevServer {
   public output: Output;
   public env: EnvConfig;
   public buildEnv: EnvConfig;
+  public files: BuilderInputs;
 
+  private cachedNowJson: NowConfig | null;
   private server: http.Server;
   private stopping: boolean;
   private buildMatches: Map<string, BuildMatch>;
   private inProgressBuilds: Map<string, Promise<void>>;
   private originalEnv: EnvConfig;
+  private nsfw?: nsfw.Watcher;
 
   constructor(cwd: string, options: DevServerOptions) {
     this.cwd = cwd;
     this.output = options.output;
     this.env = {};
     this.buildEnv = {};
+    this.files = {};
 
+    this.cachedNowJson = null;
     this.server = http.createServer(this.devServerHandler);
     this.stopping = false;
     this.buildMatches = new Map();
     this.inProgressBuilds = new Map();
     this.originalEnv = { ...process.env };
   }
 
-  async getProjectFiles(): Promise<BuilderInputs> {
-    // TODO: use the file watcher to keep the files list up-to-date
-    // incrementally, instead of re-globbing the filesystem every time
-    const files = await collectProjectFiles('**', this.cwd);
-    return files;
+  async handleFilesystemEvents(events: nsfw.Event[]): Promise<void> {
+    const filesChanged: Set<string> = new Set();
+
+    // First, update the `files` mapping of source files
+    for (const event of events) {
+      // TODO: for some reason the type inference isn't working, hence the casting
+      if (event.action === nsfw.actions.CREATED) {
+        await this.handleFileCreated(event as nsfw.CreatedEvent, filesChanged);
+      } else if (event.action === nsfw.actions.DELETED) {
+        this.handleFileDeleted(event as nsfw.DeletedEvent, filesChanged);
+      } else if (event.action === nsfw.actions.MODIFIED) {
+        await this.handleFileModified(event as nsfw.ModifiedEvent, filesChanged);
+      } else if (event.action === nsfw.actions.RENAMED) {
+        await this.handleFileRenamed(event as nsfw.RenamedEvent, filesChanged);
+      }
+    }
+    console.log('changed', filesChanged);
+
+    if (filesChanged.has('now.json')) {
+      // The `now.json` file was changed, so invalidate the in-memory copy
+      this.output.debug('Invalidating cached `now.json`');
+      this.cachedNowJson = null;
+    }
+
+    // Update the build matches in case an entrypoint was created or deleted
+    const nowJson = await this.getNowJson();
+    if (nowJson) {
+      await this.updateBuildMatches(nowJson);
+    }
+
+    // TODO: trigger rebuilds of any existing builds that are dependant
+    // on one of the files that has changed.
+  }
+
+  async handleFileCreated(event: nsfw.CreatedEvent, changed: Set<string>): Promise<void> {
+    const fsPath = join(event.directory, event.file);
+    const name = relative(this.cwd, fsPath);
+    this.output.debug(`File created: ${name}`);
+    this.files[name] = await FileFsRef.fromFsPath({ fsPath });
+    changed.add(name);
+  }
+
+  handleFileDeleted(event: nsfw.DeletedEvent, changed: Set<string>): void {
+    const name = relative(this.cwd, join(event.directory, event.file));
+    this.output.debug(`File deleted: ${name}`);
+    delete this.files[name];
+    changed.add(name);
+  }
+
+  async handleFileModified(event: nsfw.ModifiedEvent, changed: Set<string>): Promise<void> {
+    const fsPath = join(event.directory, event.file);
+    const name = relative(this.cwd, fsPath);
+    this.output.debug(`File modified: ${name}`);
+    this.files[name] = await FileFsRef.fromFsPath({ fsPath });
+    changed.add(name);
+  }
+
+  async handleFileRenamed(event: nsfw.RenamedEvent, changed: Set<string>): Promise<void> {
+    const oldName = relative(this.cwd, join(event.directory, event.oldFile));
+    changed.add(oldName);
+
+    const fsPath = join(event.newDirectory, event.newFile);
+    const name = relative(this.cwd, fsPath);
+    changed.add(name);
+
+    this.output.debug(`File renamed: ${oldName} -> ${name}`);
+    delete this.files[oldName];
+    this.files[name] = await FileFsRef.fromFsPath({ fsPath });
   }
 
   async updateBuildMatches(nowJson: NowConfig): Promise<void> {
@@ -115,15 +185,19 @@ export default class DevServer {
   }
 
   async getNowJson(): Promise<NowConfig | null> {
-    // TODO: use the file watcher to only invalidate this `nowJson`
-    // config once a change to the `now.json` file occurs
+    if (this.cachedNowJson) {
+      return this.cachedNowJson;
+    }
+
+    this.output.debug('Reading "now.json" file');
     const nowJsonPath = getNowJsonPath(this.cwd);
 
     try {
       const config: NowConfig = JSON.parse(
         await fs.readFile(nowJsonPath, 'utf8')
       );
       this.validateNowConfig(config);
+      this.cachedNowJson = config;
       return config;
     } catch (err) {
       if (err.code !== 'ENOENT') {
@@ -190,7 +264,12 @@ export default class DevServer {
    * Launches the `now dev` server.
    */
   async start(port: number = 3000): Promise<void> {
-    let address: string | null = null;
+    this.files = await collectProjectFiles('**', this.cwd);
+
+    // Start the filesystem watcher
+    this.nsfw = await nsfw(this.cwd, this.handleFilesystemEvents.bind(this));
+    await this.nsfw.start();
+
     const [env, buildEnv] = await Promise.all([
       this.getLocalEnv('.env'),
       this.getLocalEnv('.env.build')
@@ -215,14 +294,14 @@ export default class DevServer {
       );
       if (needsInitialBuild.length > 0) {
         this.output.log('Running initial builds');
-        const files = await this.getProjectFiles();
         for (const match of needsInitialBuild) {
-          await executeBuild(nowJson, this, files, match);
+          await executeBuild(nowJson, this, this.files, match);
         }
         this.output.success('Initial builds complete');
       }
     }
 
+    let address: string | null = null;
     while (typeof address !== 'string') {
       try {
         address = await listen(this.server, port);
@@ -420,7 +499,7 @@ export default class DevServer {
     nowRequestId: string,
     nowJson: NowConfig
   ) => {
-    const files = await this.getProjectFiles();
+    const files = this.files;
     await this.updateBuildMatches(nowJson);
 
     const {

yarn.lock

@@ -2946,7 +2946,7 @@ fs-extra@7.0.0:
     jsonfile "^4.0.0"
     universalify "^0.1.0"
 
-fs-extra@7.0.1:
+fs-extra@7.0.1, fs-extra@^7.0.0:
   version "7.0.1"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-7.0.1.tgz#4f189c44aa123b895f722804f55ea23eadc348e9"
   integrity sha512-YJDaCJZEnBmcbw13fvdAM9AwNOJwOzrE4pqMqBq5nFiEqXUqHwlK4B+3pUw6JNvfSPtX05xFHtYy/1ni01eGCw==
@@ -4173,6 +4173,11 @@ lodash.get@^4.4.2:
   resolved "https://registry.yarnpkg.com/lodash.get/-/lodash.get-4.4.2.tgz#2d177f652fa31e939b4438d5341499dfa3825e99"
   integrity sha1-LRd/ZS+jHpObRDjVNBSZ36OCXpk=
 
+lodash.isinteger@^4.0.4:
+  version "4.0.4"
+  resolved "https://registry.yarnpkg.com/lodash.isinteger/-/lodash.isinteger-4.0.4.tgz#619c0af3d03f8b04c31f5882840b77b11cd68343"
+  integrity sha1-YZwK89A/iwTDH1iChAt3sRzWg0M=
+
 lodash.islength@^4.0.1:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/lodash.islength/-/lodash.islength-4.0.1.tgz#4e9868d452575d750affd358c979543dc20ed577"
@@ -4183,6 +4188,11 @@ lodash.isplainobject@^4.0.6:
   resolved "https://registry.yarnpkg.com/lodash.isplainobject/-/lodash.isplainobject-4.0.6.tgz#7c526a52d89b45c45cc690b88163be0497f550cb"
   integrity sha1-fFJqUtibRcRcxpC4gWO+BJf1UMs=
 
+lodash.isundefined@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/lodash.isundefined/-/lodash.isundefined-3.0.1.tgz#23ef3d9535565203a66cefd5b830f848911afb48"
+  integrity sha1-I+89lTVWUgOmbO/VuDD4SJEa+0g=
+
 lodash.merge@4.6.x, lodash.merge@^4.6.1:
   version "4.6.1"
   resolved "https://registry.yarnpkg.com/lodash.merge/-/lodash.merge-4.6.1.tgz#adc25d9cb99b9391c59624f379fbba60d7111d54"
@@ -4556,7 +4566,7 @@ mute-stream@0.0.7:
   resolved "https://registry.yarnpkg.com/mute-stream/-/mute-stream-0.0.7.tgz#3075ce93bc21b8fab43e1bc4da7e8115ed1e7bab"
   integrity sha1-MHXOk7whuPq0PhvE2n6BFe0ee6s=
 
-nan@^2.9.2:
+nan@^2.0.0, nan@^2.9.2:
   version "2.13.2"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.13.2.tgz#f51dc7ae66ba7d5d55e1e6d4d8092e802c9aefe7"
   integrity sha512-TghvYc72wlMGMVMluVo9WRJc0mB8KxxF/gZ4YYFy7V2ZQX9l7rgbPg7vjS9mt6U5HXODVFVI2bOduCzwOMv/lw==
@@ -4725,6 +4735,16 @@ npmlog@^4.0.2:
     gauge "~2.7.3"
     set-blocking "~2.0.0"
 
+nsfw@1.2.2:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/nsfw/-/nsfw-1.2.2.tgz#95b79b6b0e311268aaa20c5c085b9f3b341b0769"
+  integrity sha512-YwoS39dkrp6loO0gvh61UbQPiOYwmbAiKqWSYuMeoSkpxxy8rbe/RVgxIJ1L+ua5usLGr0FPSo7NEQnDQOGyIw==
+  dependencies:
+    fs-extra "^7.0.0"
+    lodash.isinteger "^4.0.4"
+    lodash.isundefined "^3.0.1"
+    nan "^2.0.0"
+
 number-is-nan@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/number-is-nan/-/number-is-nan-1.0.1.tgz#097b602b53422a522c1afb8790318336941a011d"