Install App Dependencies

- Spawns an npm install command from the App root
- Has some special OS checks for windows command spawning

core/server/apps/dependencies.js

@@ -0,0 +1,52 @@
+
+var _ = require('lodash'),
+    fs = require('fs'),
+    path = require('path'),
+    when = require('when'),
+    spawn = require('child_process').spawn,
+    win32 = process.platform === 'win32';
+
+function AppDependencies(appPath) {
+    this.appPath = appPath;
+}
+
+AppDependencies.prototype.install = function installAppDependencies() {
+    var def = when.defer(),
+        spawnOpts;
+
+    fs.exists(path.join(this.appPath, 'package.json'), function (exists) {
+        if (!exists) {
+            // Nothing to do, resolve right away?
+            def.resolve();
+        } else {
+            // Run npm install in the app directory
+            spawnOpts = {
+                cwd: this.appPath
+            };
+
+            this.spawnCommand('npm', ['install', '--production'], spawnOpts)
+                .on('error', def.reject)
+                .on('exit', function (err) {
+                    if (err) {
+                        def.reject(err);
+                    }
+
+                    def.resolve();
+                });
+        }
+    }.bind(this));
+
+    return def.promise;
+};
+
+// Normalize a command across OS and spawn it; taken from yeoman/generator
+AppDependencies.prototype.spawnCommand = function (command, args, opt) {
+    var winCommand = win32 ? 'cmd' : command,
+        winArgs = win32 ? ['/c'].concat(command, args) : args;
+
+    opt = opt || {};
+
+    return spawn(winCommand, winArgs, _.defaults({ stdio: 'inherit' }, opt));
+};
+
+module.exports = AppDependencies;

core/server/apps/loader.js

@@ -5,14 +5,20 @@ var path = require('path'),
     appProxy = require('./proxy'),
     config = require('../config'),
     AppSandbox = require('./sandbox'),
+    AppDependencies = require('./dependencies'),
     loader;
 
+// Get the full path to an app by name
+function getAppAbsolutePath(name) {
+    return path.join(config().paths.appPath, name);
+}
+
 // Get a relative path to the given apps root, defaults
 // to be relative to __dirname
 function getAppRelativePath(name, relativeTo) {
     relativeTo = relativeTo || __dirname;
 
-    return path.relative(relativeTo, path.join(config().paths.appPath, name));
+    return path.relative(relativeTo, getAppAbsolutePath(name));
 }
 
 // Load apps through a psuedo sandbox
@@ -41,6 +47,9 @@ function getAppByName(name) {
 loader = {
     // Load a app and return the instantiated app
     installAppByName: function (name) {
+        // Install the apps dependendencies first
+        var deps = new AppDependencies(getAppAbsolutePath(name));
+        return deps.install().then(function () {
             var app = getAppByName(name);
 
             // Check for an install() method on the app.
@@ -48,11 +57,13 @@ loader = {
                 return when.reject(new Error("Error loading app named " + name + "; no install() method defined."));
             }
 
+            // Run the app.install() method
             // Wrapping the install() with a when because it's possible
             // to not return a promise from it.
             return when(app.install(appProxy)).then(function () {
                 return when.resolve(app);
             });
+        });
     },
 
     // Activate a app and return it

core/test/unit/apps_spec.js

@@ -1,6 +1,7 @@
 /*globals describe, beforeEach, afterEach,  before, it*/
 var fs           = require('fs'),
     path         = require('path'),
+    EventEmitter = require('events').EventEmitter,
     should       = require('should'),
     sinon        = require('sinon'),
     _            = require('lodash'),
@@ -9,7 +10,8 @@ var fs         = require('fs'),
 
     // Stuff we are testing
     appProxy   = require('../../server/apps/proxy'),
-    AppSandbox = require('../../server/apps/sandbox');
+    AppSandbox = require('../../server/apps/sandbox'),
+    AppDependencies = require('../../server/apps/dependencies');
 
 describe('Apps', function () {
 
@@ -154,4 +156,37 @@ describe('Apps', function () {
             loadApp.should.throw(/^Unsafe App require[\w\W]*example$/);
         });
     });
+
+    describe('Dependencies', function () {
+        it('can install by package.json', function (done) {
+            var deps = new AppDependencies(process.cwd()),
+                fakeEmitter = new EventEmitter();
+
+            deps.spawnCommand = sandbox.stub().returns(fakeEmitter);
+
+            deps.install().then(function () {
+                deps.spawnCommand.calledWith('npm').should.equal(true);
+                done();
+            }).otherwise(done);
+
+            _.delay(function () {
+                fakeEmitter.emit('exit');
+            }, 30);
+        });
+        it('does not install when no package.json', function (done) {
+            var deps = new AppDependencies(__dirname),
+                fakeEmitter = new EventEmitter();
+
+            deps.spawnCommand = sandbox.stub().returns(fakeEmitter);
+
+            deps.install().then(function () {
+                deps.spawnCommand.called.should.equal(false);
+                done();
+            }).otherwise(done);
+
+            _.defer(function () {
+                fakeEmitter.emit('exit');
+            });
+        });
+    });
 });