Bi directional communication (#100)

* Use 'child.stdin.write' to send 'eject' command

* Fix bug where app would crash after ejecting with modal open

* Cleanup

* Improve fix to use getDerivedStateFromProps

src/components/TaskRunnerPane/TaskRunnerPane.js

@@ -27,6 +27,21 @@ class TaskRunnerPane extends Component<Props, State> {
     selectedTaskId: null,
   };
 
+  static getDerivedStateFromProps(props, state) {
+    // It's possible that this task is deleted while the modal is open;
+    // For example, This can happen when ejecting the project, since the
+    // create-react-app "eject" task removes itself upon completion.
+    const selectedTaskExists = props.tasks.some(
+      task => task.id === state.selectedTaskId
+    );
+
+    if (!selectedTaskExists) {
+      return { selectedTaskId: null };
+    }
+
+    return null;
+  }
+
   handleToggleTask = taskId => {
     const { tasks, runTask, abortTask } = this.props;
 

src/middlewares/task.middleware.js

@@ -132,16 +132,8 @@ export default (store: any) => (next: any) => (action: any) => {
         additionalArgs.push('--', '--coverage');
       }
 
-      /* Bypasses 'Are you sure?' check when ejecting CRA
-       *
-       * TODO: add windows support
-       */
-      const command =
-        project.type === 'create-react-app' && name === 'eject'
-          ? 'echo yes | npm'
-          : 'npm';
       const child = childProcess.spawn(
-        command,
+        'npm',
         ['run', name, ...additionalArgs],
         {
           cwd: projectPath,
@@ -158,6 +150,20 @@ export default (store: any) => (next: any) => (action: any) => {
       next(attachTaskMetadata(task, child.pid));
 
       child.stdout.on('data', data => {
+        // The 'eject' task prompts the user, to ask if they're sure.
+        // We can bypass this prompt, as our UI already has an alert that
+        // confirms this action.
+        // TODO: Eject deserves its own Redux action, to avoid cluttering up
+        // this generic "RUN_TASK" action.
+        // TODO: Is there a way to "future-proof" this, in case the CRA
+        // confirmation copy changes?
+        const isEjectPrompt = data
+          .toString()
+          .includes('Are you sure you want to eject? This action is permanent');
+
+        if (isEjectPrompt) {
+          sendCommandToProcess(child, 'y');
+        }
         next(receiveDataFromTaskExecution(task, data.toString()));
       });
 
@@ -270,3 +276,9 @@ const getDevServerCommand = (
       throw new Error('Unrecognized project type: ' + projectType);
   }
 };
+
+const sendCommandToProcess = (child: any, command: string) => {
+  // Commands have to be suffixed with '\n' to signal that the command is
+  // ready to be sent. Same as a regular command + hitting the enter key.
+  child.stdin.write(`${command}\n`);
+};