feat(wds): install node_modules when missing on project open (fixes #102

)

src/server/tasks/task.ts

@@ -159,7 +159,7 @@ export abstract class Task<T> {
   /**
    * Runs the subtask and waits for it to complete.
    */
-  protected async awaitSubtask(task: Task<T>): Promise<T> {
+  protected async awaitSubtask<R>(task: Task<R>): Promise<R> {
     this.subtasks.add(task);
     const retValue = await task.start();
     await task.untilStopped;

src/server/webpack-task.ts

@@ -12,6 +12,7 @@ import { MissingWebpackConfig } from './errors';
 import { Project } from './project';
 import { ConsoleTask } from './tasks/console-task';
 import { exists } from './util';
+import { NpmInstallTask } from './tasks/npm-install-task';
 
 /**
  * Just making a note of some investigations here. *Ideally* I wanted to embed
@@ -61,9 +62,15 @@ export abstract class WebpackTask<T> extends ConsoleTask<T> {
       throw new MissingWebpackConfig();
     }
 
-    const [out, process] = await this.startWebpack(config);
     this.state.next(WebpackState.Starting);
 
+    if (!(await exists(this.project.baseDir('node_modules')))) {
+      this.data.next('Node modules not found, starting installation. This may take a minute.\n');
+      await this.installNodeModules();
+    }
+
+    const [out, process] = await this.startWebpack(config);
+
     process.on('exit', code => {
       if (code === 0) {
         this.state.next(WebpackState.Stopped);
@@ -82,6 +89,16 @@ export abstract class WebpackTask<T> extends ConsoleTask<T> {
     this.state.next(WebpackState.Stopping);
   }
 
+  /**
+   * Runs npm install. This is called when starting webpack if we detect
+   * that the user doesn't have their modules installed.
+   */
+  protected async installNodeModules() {
+    const task = new NpmInstallTask(this.project.baseDir());
+    task.data.subscribe(data => this.data.next(data));
+    await this.awaitSubtask(task);
+  }
+
   /**
    * Reads stdout/err from the process and dispatches it accordingly.
    */