fix(local-process): error if content folder owned by other user

closes TryGhost#501
- if the content folder is owned by a separate user, the local process manager will fail
- improve local process manager errors
- add local process manager tests

Author: acburdine

lib/utils/local-process.js

@@ -1,5 +1,6 @@
 'use strict';
 const fs = require('fs-extra');
+const os = require('os');
 const path = require('path');
 const fkill = require('fkill');
 const spawn = require('child_process').spawn;
@@ -28,6 +29,14 @@ class LocalProcess extends ProcessManager {
      * @public
      */
     start(cwd, environment) {
+        const stat = fs.lstatSync(path.join(cwd, 'content'));
+
+        // Check that content folder is owned by the current user
+        if (stat.uid !== process.getuid()) {
+            return Promise.reject(new errors.SystemError(`The content folder is not owned by the current user.
+Please ensure the content folder has correct permissions and try again.`));
+        }
+
         return new Promise((resolve, reject) => {
             const cp = spawn('node', [process.argv[1] , 'run'], {
                 cwd: cwd,
@@ -39,7 +48,12 @@ class LocalProcess extends ProcessManager {
             // Stick the pid into the pidfile so we can stop the process later
             fs.writeFileSync(path.join(cwd, PID_FILE), cp.pid);
 
-            cp.on('error', reject);
+            cp.on('error', (error) => {
+                reject(new errors.CliError({
+                    message: 'An error occurred while starting Ghost.',
+                    err: error
+                }));
+            });
 
             cp.on('exit', (code) => {
                 fs.removeSync(path.join(cwd, PID_FILE));
@@ -50,8 +64,7 @@ class LocalProcess extends ProcessManager {
             cp.on('message', (msg) => {
                 if (msg.error) {
                     fs.removeSync(path.join(cwd, PID_FILE));
-
-                    return reject(new errors.GhostError(msg));
+                    return reject(new errors.GhostError(msg.error));
                 }
 
                 if (msg.started) {
@@ -80,18 +93,24 @@ class LocalProcess extends ProcessManager {
         } catch (e) {
             if (e.code === 'ENOENT') {
                 // pid was not found, exit
-                return;
+                return Promise.resolve();
             }
 
-            throw e;
+            return Promise.reject(new errors.CliError({
+                message: 'An unexpected error occurred when reading the pidfile.',
+                error: e
+            }));
         }
 
-        const isWindows = process.platform === 'win32';
+        const isWindows = os.platform() === 'win32';
 
         return fkill(pid, {force: isWindows}).catch((error) => {
             // TODO: verify windows outputs same error message as mac/linux
             if (!error.message.match(/No such process/)) {
-                throw error;
+                return Promise.reject(new errors.CliError({
+                    message: 'An unexpected error occurred while stopping Ghost.',
+                    err: error
+                }));
             }
         }).then(() => {
             fs.removeSync(path.join(cwd, PID_FILE));