Auto-updating development mode on file changes

README.md

@@ -28,6 +28,7 @@ zeplin connect [options]
 |--------------|---------------------------------------------------|-------------------------|
 | -f, --file   | Path to components configuration file             | .zeplin/components.json |
 | -d, --dev    | Activate development mode                         | false                   |
+| --no-watch   | Disable watching file changes on development mode | false                   |
 | -p, --plugin | npm package name of a Zeplin CLI `connect` plugin |                         |
 | -h, --help   | Output usage information                          |                         |
 | --verbose    | Enable verbose logs                               |                         |

package.json

@@ -58,6 +58,7 @@
     "@hapi/joi": "^16.1.7",
     "axios": "^0.19.0",
     "chalk": "^3.0.0",
+    "chokidar": "^3.3.1",
     "ci-info": "^2.0.0",
     "commander": "^4.1.0",
     "endent": "^1.3.0",

src/app.ts

@@ -48,12 +48,14 @@ const connectCommand = program.command("connect")
     .description("Connect components to code")
     .option("-f, --file <file>", "Full path to components file", createCollector(), defaults.commands.connect.filePaths)
     .option("-d, --dev", "Activate development mode", defaults.commands.connect.devMode)
+    .option("--no-watch", "Disable watch files on development mode", defaults.commands.connect.devModeWatch)
     .option("-p, --plugin <plugin>", "npm package name of a Zeplin CLI connect plugin", createCollector(), [])
     .action(commandRunner(async options => {
         const connectOptions: ConnectOptions = {
             configFiles: options.file,
             devMode: options.dev,
             devModePort: defaults.commands.connect.port,
+            devModeWatch: options.watch,
             plugins: options.plugin
         };
 

src/commands/connect/index.ts

@@ -1,55 +1,110 @@
 import chalk from "chalk";
+import chokidar from "chokidar";
 import dedent from "ts-dedent";
-
+import logger from "../../util/logger";
+import { indent } from "../../util/text";
 import { getComponentConfigFiles } from "./config";
+import { ConnectedBarrelComponents } from "./interfaces/api";
 import { connectComponentConfigFiles } from "./plugin";
 import { ConnectDevServer } from "./server";
 import { ConnectedComponentsService } from "./service";
-import { indent } from "../../util/text";
-import logger from "../../util/logger";
 
-export interface ConnectOptions {
-    configFiles: string[];
-    devMode: boolean;
-    devModePort: number;
-    plugins: string[];
-}
+const connectComponents = async (options: ConnectOptions): Promise<ConnectedBarrelComponents[]> => {
+    const {
+        configFiles,
+        plugins
+    } = options;
 
-export async function connect(options: ConnectOptions): Promise<void> {
-    try {
-        logger.debug(`connect options: ${JSON.stringify(options)}`);
+    const componentConfigFiles = await getComponentConfigFiles(configFiles, plugins);
 
-        const {
-            configFiles,
-            plugins,
-            devMode,
-            devModePort
-        } = options;
+    logger.debug(`component config files: ${JSON.stringify(componentConfigFiles)}`);
 
-        const componentConfigFiles = await getComponentConfigFiles(configFiles, plugins);
+    const connectedBarrels = await connectComponentConfigFiles(componentConfigFiles);
 
-        logger.debug(`component config files: ${JSON.stringify(componentConfigFiles)}`);
+    logger.debug(`connected barrels output: ${JSON.stringify(connectedBarrels)}`);
 
-        const connectedBarrels = await connectComponentConfigFiles(componentConfigFiles);
+    return connectedBarrels;
+};
 
-        logger.debug(`connected barrels output: ${JSON.stringify(connectedBarrels)}`);
+const startDevServer = async (
+    options: ConnectOptions,
+    connectedBarrels: ConnectedBarrelComponents[]
+): Promise<void> => {
+    const {
+        configFiles,
+        devModePort,
+        devModeWatch
+    } = options;
 
-        if (devMode) {
-            logger.info("Starting development server…");
+    logger.info("Starting development server…");
 
-            const devServer = new ConnectDevServer(connectedBarrels);
+    const devServer = new ConnectDevServer(connectedBarrels);
 
-            await devServer.start(devModePort);
+    await devServer.start(devModePort);
 
-            logger.info(`Development server is started on port ${devModePort}!`);
-        } else {
-            logger.info("Connecting all connected components into Zeplin…");
+    logger.info(chalk.green(`Development server is started on port ${devModePort}.`));
 
-            const service = new ConnectedComponentsService();
+    if (devModeWatch) {
+        const componentFiles = connectedBarrels?.map(f =>
+            f.connectedComponents.map(c => c.path)
+        ).reduce((a, b) => [...a, ...b], []);
 
-            await service.uploadConnectedBarrels(connectedBarrels);
+        const watcher = chokidar.watch(
+            [...configFiles, ...componentFiles],
+            {
+                cwd: process.cwd(),
+                persistent: true,
+                awaitWriteFinish: true
+            }
+        );
 
-            logger.info("🦄 Components successfully connected to components in Zeplin.");
+        watcher.on("change", async path => {
+            logger.info((chalk.yellow(`\nFile change detected ${path}.\n`)));
+
+            try {
+                const updatedConnectedBarrels = await connectComponents(options);
+
+                await devServer.stop();
+
+                watcher.close().then(() => startDevServer(options, updatedConnectedBarrels));
+            } catch (error) {
+                logger.error(chalk.red(dedent`
+                    Could not restart development server.
+                    ${error}
+                `));
+            }
+        });
+    }
+};
+
+const upload = async (connectedBarrels: ConnectedBarrelComponents[]): Promise<void> => {
+    logger.info("Connecting all connected components into Zeplin…");
+
+    const service = new ConnectedComponentsService();
+
+    await service.uploadConnectedBarrels(connectedBarrels);
+
+    logger.info("🦄 Components successfully connected to components in Zeplin.");
+};
+
+export interface ConnectOptions {
+    configFiles: string[];
+    devMode: boolean;
+    devModePort: number;
+    devModeWatch: boolean;
+    plugins: string[];
+}
+
+export async function connect(options: ConnectOptions): Promise<void> {
+    try {
+        logger.debug(`connect options: ${JSON.stringify(options)}`);
+
+        const connectedBarrels = await connectComponents(options);
+
+        if (options.devMode) {
+            await startDevServer(options, connectedBarrels);
+        } else {
+            await upload(connectedBarrels);
         }
     } catch (error) {
         error.message = dedent`

src/commands/connect/plugin.ts

@@ -100,6 +100,7 @@ const connectComponentConfig = async (
     const pluginPromises = plugins.map(async plugin => {
         try {
             if (plugin.supports(component)) {
+                logger.debug(`${plugin.name} supports ${component.path}. Processing…`);
                 const componentData = await plugin.process(component);
 
                 data.push({
@@ -110,6 +111,10 @@ const connectComponentConfig = async (
                 componentData.links?.forEach(link =>
                     urlPaths.push(processLink(link))
                 );
+
+                logger.debug(`${plugin.name} processed ${component.path}: ${componentData}`);
+            } else {
+                logger.debug(`${plugin.name} does not support ${component.path}.`);
             }
         } catch (err) {
             throw new CLIError(dedent`

src/commands/connect/server/index.ts

@@ -1,10 +1,16 @@
 import express from "express";
-import { ConnectedBarrelComponents, ConnectedComponent } from "../interfaces/api";
-import { CLIError } from "../../../errors";
+import { Server } from "http";
 import { OK } from "http-status-codes";
+import { Socket } from "net";
+import { CLIError } from "../../../errors";
+import logger from "../../../util/logger";
+import { ConnectedBarrelComponents, ConnectedComponent } from "../interfaces/api";
 
 export class ConnectDevServer {
     connectedBarrels: ConnectedBarrelComponents[] = [];
+    stopped = false;
+    server: Server | undefined;
+    connections: Socket[] = [];
 
     constructor(connectedBarrels: ConnectedBarrelComponents[]) {
         this.connectedBarrels = connectedBarrels;
@@ -18,7 +24,11 @@ export class ConnectDevServer {
         return found ? found.connectedComponents : null;
     }
 
-    start(port: number): Promise<void> {
+    start(port: number): Promise<Server> {
+        if (this.server && this.server.listening) {
+            return Promise.resolve(this.server);
+        }
+
         const app = express();
 
         // CORS
@@ -37,16 +47,37 @@ export class ConnectDevServer {
             return res.status(OK).json({ connectedComponents });
         });
 
-        const promise = new Promise<void>((resolve, reject): void => {
-            app.listen(port, resolve)
+        return new Promise<Server>((resolve, reject): void => {
+            this.server = app.listen(port)
+                .on("listening", () => {
+                    logger.debug(`Started dev server on port ${port}`);
+                    resolve(this.server);
+                })
                 .on("error", (err: NodeJS.ErrnoException) => {
                     if (err.code === "EADDRINUSE") {
                         reject(new CLIError(`Port ${port} is already in use.`));
                     }
+                })
+                .on("connection", connection => {
+                    this.connections.push(connection);
+                    connection.on("close", () =>
+                        (this.connections = this.connections.filter(curr => curr !== connection))
+                    );
                 });
         });
+    }
+
+    stop(): Promise<void> {
+        logger.debug("Stopping dev server.");
+
+        this.stopped = true;
+        this.connections.forEach(conn => conn.end());
 
-        return promise;
+        return new Promise((resolve): void => {
+            this.server?.close(() => {
+                logger.debug("Stopped dev server.");
+                resolve();
+            });
+        });
     }
 }
-

src/config/defaults.ts

@@ -3,6 +3,7 @@ export const defaults = {
         connect: {
             filePaths: [".zeplin/components.json"],
             devMode: false,
+            devModeWatch: true,
             port: 9756
         }
     },