Add support for ES6 style async boot scripts

lib/plugins/boot-script.js

@@ -81,23 +81,24 @@ function runScripts(app, list, callback) {
 
   async.eachSeries(functions, function(f, done) {
     debug('Running script %s', f.path);
-    if (f.func.length >= 2) {
-      debug('Starting async function %s', f.path);
-      f.func(app, function(err) {
-        debug('Async function finished %s', f.path);
-        done(err);
-      });
-    } else {
-      debug('Starting sync function %s', f.path);
-      var error;
-      try {
-        f.func(app);
+    var cb = function(err) {
+      debug('Async function %s %s', err ? 'failed' : 'finished', f.path);
+      done(err);
+      // Make sure done() isn't called twice, e.g. if a script returns a
+      // thenable object and also calls the passed callback.
+      cb = function() {};
+    };
+    try {
+      var result = f.func(app, cb);
+      if (result && typeof result.then === 'function') {
+        result.then(function() { cb(); }, cb);
+      } else if (f.func.length < 2) {
         debug('Sync function finished %s', f.path);
-      } catch (err) {
-        debug('Sync function failed %s', f.path, err);
-        error = err;
+        done();
       }
-      done(error);
+    } catch (err) {
+      debug('Sync function failed %s', f.path, err);
+      done(err);
     }
   }, callback);
 }

test/executor.test.js

@@ -306,9 +306,15 @@ describe('executor', function() {
         'barLoaded',
         'barSyncLoaded',
         'fooLoaded',
+        'promiseLoaded',
+        'thenableLoaded',
         'barStarted',
         'barFinished',
         'barSyncExecuted',
+        'promiseStarted',
+        'promiseFinished',
+        'thenableStarted',
+        'thenableFinished',
       ]);
     });
   });
@@ -322,60 +328,132 @@ describe('executor', function() {
             'barLoaded',
             'barSyncLoaded',
             'fooLoaded',
+            'promiseLoaded',
+            'thenableLoaded',
             'barStarted',
             'barFinished',
             'barSyncExecuted',
+            'promiseStarted',
+            'promiseFinished',
+            'thenableStarted',
+            'thenableFinished',
           ]);
           done();
         });
       });
     });
+  });
 
-    describe('for mixins', function() {
-      var options;
-      beforeEach(function() {
-        appdir.writeFileSync('custom-mixins/example.js',
-          'module.exports = ' +
-          'function(Model, options) {}');
+  describe('with boot script returning a rejected promise', function() {
+    before(function() {
+      // Tell simple-app/boot/reject.js to return a rejected promise
+      process.rejectPromise = true;
+    });
 
-        appdir.writeFileSync('custom-mixins/time-stamps.js',
-          'module.exports = ' +
-          'function(Model, options) {}');
+    after(function() {
+      delete process.rejectPromise;
+    });
 
-        appdir.writeConfigFileSync('custom-mixins/time-stamps.json', {
-          name: 'Timestamping',
+    it('receives rejected promise as callback error',
+    function(done) {
+      simpleAppInstructions(function(err, context) {
+        if (err) return done(err);
+        boot.execute(app, context.instructions, function(err) {
+          expect(err).to.exist.and.be.an.instanceOf(Error)
+            .with.property('message', 'reject');
+          done();
         });
-
-        options = {
-          appRootDir: appdir.PATH,
-        };
       });
+    });
+  });
 
-      it('defines mixins from instructions - using `mixinDirs`',
-        function(done) {
-          options.mixinDirs = ['./custom-mixins'];
-          boot(app, options, function(err) {
-            if (err) return done(err);
-            var modelBuilder = app.registry.modelBuilder;
-            var registry = modelBuilder.mixins.mixins;
-            expect(Object.keys(registry)).to.eql(['Example', 'Timestamping']);
-            done();
-          });
+  describe('with boot script throwing an error', function() {
+    before(function() {
+      // Tell simple-app/boot/throw.js to throw an error
+      process.throwError = true;
+    });
+
+    after(function() {
+      delete process.throwError;
+    });
+
+    it('receives thrown error as callback errors',
+    function(done) {
+      simpleAppInstructions(function(err, context) {
+        if (err) return done(err);
+        boot.execute(app, context.instructions, function(err) {
+          expect(err).to.exist.and.be.an.instanceOf(Error)
+            .with.property('message', 'throw');
+          done();
         });
+      });
+    });
+  });
 
-      it('defines mixins from instructions - using `mixinSources`',
-        function(done) {
-          options.mixinSources = ['./custom-mixins'];
-          boot(app, options, function(err) {
-            if (err) return done(err);
+  describe('with boot script returning a promise and calling callback',
+    function() {
+      before(function() {
+        process.promiseAndCallback = true;
+      });
 
-            var modelBuilder = app.registry.modelBuilder;
-            var registry = modelBuilder.mixins.mixins;
-            expect(Object.keys(registry)).to.eql(['Example', 'Timestamping']);
-            done();
-          });
+      after(function() {
+        delete process.promiseAndCallback;
+      });
+
+      it('should only call the callback once', function(done) {
+        simpleAppInstructions(function(err, context) {
+          if (err) return done(err);
+          // Note: Mocha will fail this test if done() is called twice
+          boot.execute(app, context.instructions, done);
         });
+      });
+    }
+  );
+
+  describe('for mixins', function() {
+    var options;
+    beforeEach(function() {
+      appdir.writeFileSync('custom-mixins/example.js',
+        'module.exports = ' +
+        'function(Model, options) {}');
+
+      appdir.writeFileSync('custom-mixins/time-stamps.js',
+        'module.exports = ' +
+        'function(Model, options) {}');
+
+      appdir.writeConfigFileSync('custom-mixins/time-stamps.json', {
+        name: 'Timestamping',
+      });
+
+      options = {
+        appRootDir: appdir.PATH,
+      };
     });
+
+    it('defines mixins from instructions - using `mixinDirs`',
+      function(done) {
+        options.mixinDirs = ['./custom-mixins'];
+        boot(app, options, function(err) {
+          if (err) return done(err);
+          var modelBuilder = app.registry.modelBuilder;
+          var registry = modelBuilder.mixins.mixins;
+          expect(Object.keys(registry)).to.eql(['Example', 'Timestamping']);
+          done();
+        });
+      });
+
+    it('defines mixins from instructions - using `mixinSources`',
+      function(done) {
+        options.mixinSources = ['./custom-mixins'];
+        boot(app, options, function(err) {
+          if (err) return done(err);
+
+          var modelBuilder = app.registry.modelBuilder;
+          var registry = modelBuilder.mixins.mixins;
+          expect(Object.keys(registry)).to.eql(['Example', 'Timestamping']);
+          done();
+        });
+      });
   });
 
   describe('with PaaS and npm env variables', function() {

test/fixtures/simple-app/boot/promise-callback.js

@@ -0,0 +1,15 @@
+// Copyright IBM Corp. 2017. All Rights Reserved.
+// Node module: loopback-boot
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+'use strict';
+
+var Promise = require('bluebird');
+
+module.exports = function(app, callback) {
+  callback();
+  if (process.promiseAndCallback) {
+    return Promise.reject();
+  }
+};

test/fixtures/simple-app/boot/promise.js

@@ -0,0 +1,21 @@
+// Copyright IBM Corp. 2017. All Rights Reserved.
+// Node module: loopback-boot
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+'use strict';
+
+var Promise = require('bluebird');
+
+process.bootFlags.push('promiseLoaded');
+module.exports = function(app) {
+  process.bootFlags.push('promiseStarted');
+  return Promise.resolve({
+    then: function(onFulfill, onReject) {
+      process.nextTick(function() {
+        process.bootFlags.push('promiseFinished');
+        onFulfill();
+      });
+    },
+  });
+};

test/fixtures/simple-app/boot/reject.js

@@ -0,0 +1,14 @@
+// Copyright IBM Corp. 2017. All Rights Reserved.
+// Node module: loopback-boot
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+'use strict';
+
+var Promise = require('bluebird');
+
+module.exports = function(app) {
+  if (process.rejectPromise) {
+    return Promise.reject(new Error('reject'));
+  }
+};

test/fixtures/simple-app/boot/thenable.js

@@ -0,0 +1,19 @@
+// Copyright IBM Corp. 2017. All Rights Reserved.
+// Node module: loopback-boot
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+'use strict';
+
+process.bootFlags.push('thenableLoaded');
+module.exports = function(app) {
+  process.bootFlags.push('thenableStarted');
+  return {
+    then: function(onFulfill, onReject) {
+      process.nextTick(function() {
+        process.bootFlags.push('thenableFinished');
+        onFulfill();
+      });
+    },
+  };
+};

test/fixtures/simple-app/boot/throw.js

@@ -0,0 +1,12 @@
+// Copyright IBM Corp. 2017. All Rights Reserved.
+// Node module: loopback-boot
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+'use strict';
+
+module.exports = function(app) {
+  if (process.throwError) {
+    throw new Error('throw');
+  }
+};