first commit for general discussion

lib/application.js

@@ -19,6 +19,7 @@ var classify = require('underscore.string/classify');
 var camelize = require('underscore.string/camelize');
 var path = require('path');
 var util = require('util');
+var Promise = require('bluebird');
 
 /**
  * The `App` object represents a Loopback application.
@@ -404,30 +405,133 @@ app.enableAuth = function(options) {
 };
 
 app._verifyAuthModelRelations = function() {
+  let self = this;
+
   // Allow unit-tests (but also LoopBack users) to disable the warnings
-  if (this.get('_verifyAuthModelRelations') === false) return;
+  const warnOnBadSetup = self.get('_disableAuthModelRelationsWarnings') !== true;
+  // Prevent the app from being killed although the configuration is inconsistent
+  const dismissRejection = self.get('_dismissBadUserConfigRejection') !== true;
 
-  const AccessToken = this.registry.findModel('AccessToken');
-  const User = this.registry.findModel('User');
-  this.models().forEach(Model => {
-    if (Model === AccessToken || Model.prototype instanceof AccessToken) {
-      scheduleVerification(Model, verifyAccessTokenRelations);
-    }
+  const AccessToken = self.registry.findModel('AccessToken');
+  const User = self.registry.findModel('User');
+  const models = self.models();
 
-    if (Model === User || Model.prototype instanceof User) {
-      scheduleVerification(Model, verifyUserRelations);
-    }
+  verifyUserModelsSetup().then(()=> {
+    verifyRelationsSetup();
   });
 
+  function verifyUserModelsSetup() {
+    let userModels = models.filter(model => {
+      return (model === User || model.prototype instanceof User) ||
+        (model === AccessToken || model.prototype instanceof AccessToken);
+    });
+
+    // we use Promise.reflect() here to let all the tests go without throwing,
+    // this way we can get all the logs for all models we are checking
+    return Promise.map(userModels, (model) => {
+      return scheduleVerification(model, hasMultipleUserModelsConfig).reflect();
+    })
+    .then((inspections) => {
+      // proceed to next checkups if no error
+      let hasErrors = inspections.filter(inspection => {
+        return inspection.isRejected();
+      });
+      if (!hasErrors.length) {
+        return;
+      }
+
+      // else log and eventually kill the app
+      console.warn('Application setup is inconsistent: some models are set to use ' +
+        'the Multiple user models configuration while some other models are set to ' +
+        'use the Single user model configuration. The model config is listed below.');
+
+      // detailed logs
+      inspections.forEach(inspection => {
+        let modelSetup = (inspection.value() || inspection.reason()).modelSetup;
+        console.warn(
+          'Model %j of type %j is set to use the %j user model config',
+          modelSetup.model,
+          modelSetup.instanceOf,
+          modelSetup.hasMultipleUserModelsConfig ? 'Multiple' : 'Single'
+        );
+      });
+
+      delete self.hasMultipleUserModelsConfig;
+
+      if (!dismissRejection) {
+        throw new Error('Application setup is inconsistent, please see the log for more ' +
+          'information');
+      }
+    });
+  }
+
+  function verifyRelationsSetup() {
+    models.forEach(Model => {
+      if (Model === AccessToken || Model.prototype instanceof AccessToken) {
+        scheduleVerification(Model, verifyAccessTokenRelations);
+      }
+
+      if (Model === User || Model.prototype instanceof User) {
+        scheduleVerification(Model, verifyUserRelations);
+      }
+    });
+  }
+
+  // instant or scheduled Model verifications, as a promise
   function scheduleVerification(Model, verifyFn) {
-    if (Model.dataSource) {
-      verifyFn(Model);
-    } else {
-      Model.on('attached', () => verifyFn(Model));
+    return new Promise((resolve, reject) => {
+      if (Model.dataSource) {
+        try {
+          resolve(verifyFn(Model));
+        } catch (e) {
+          reject(e);
+        }
+      } else {
+        Model.on('attached', () => {
+          scheduleVerification(Model, verifyFn);
+        });
+      }
+    });
+  }
+
+  function hasMultipleUserModelsConfig(model) {
+    let hasMultipleUserModelsConfig, isInstanceOfUser;
+
+    // check is the model is set to use mutiple users config (with polymorphic relations)
+    if (model === User || model.prototype instanceof User) {
+      isInstanceOfUser = true;
+      const hasManyTokens = model.relations && model.relations.accessTokens;
+      hasMultipleUserModelsConfig = !!hasManyTokens.polymorphic;
+    } else if (model === AccessToken || model.prototype instanceof AccessToken) {
+      const belongsToUser = model.relations && model.relations.user;
+      // the test on belongsToUser is required as we allow AccessToken model not
+      // to define the relation with custom user model for backward compatibility
+      // see https://github.com/strongloop/loopback/pull/3227
+      hasMultipleUserModelsConfig = !!(belongsToUser && belongsToUser.polymorphic);
     }
+
+    let modelSetup = {
+      model: model.modelName,
+      instanceOf: isInstanceOfUser ? 'User' : 'AccesToken',
+      hasMultipleUserModelsConfig,
+    };
+
+    // check if model config is consistent with already parsed models' config
+    if (self.hasMultipleUserModelsConfig === undefined) {
+      self.hasMultipleUserModelsConfig = hasMultipleUserModelsConfig;
+    } else if (self.hasMultipleUserModelsConfig !== hasMultipleUserModelsConfig) {
+      let error = new Error('User models setup is inconsistent');
+      error.modelSetup = modelSetup;
+      throw error;
+    }
+
+    // if no error, return the modelSetup for further logging purposes
+    return {modelSetup};
   }
 
   function verifyAccessTokenRelations(Model) {
+    if (!warnOnBadSetup) return;
+
     const belongsToUser = Model.relations && Model.relations.user;
     if (belongsToUser) return;
 
@@ -454,6 +558,8 @@ app._verifyAuthModelRelations = function() {
   }
 
   function verifyUserRelations(Model) {
+    if (!warnOnBadSetup) return;
+
     const hasManyTokens = Model.relations && Model.relations.accessTokens;
     if (hasManyTokens) return;
 

test/user.test.js

@@ -2442,7 +2442,7 @@ describe('User', function() {
     it('handles subclassed user with no accessToken relation', () => {
       // setup a new LoopBack app, we don't want to use shared models
       app = loopback({localRegistry: true, loadBuiltinModels: true});
-      app.set('_verifyAuthModelRelations', false);
+      app.set('_disableAuthModelRelationsWarnings', true);
       app.set('remoting', {errorHandler: {debug: true, log: false}});
       app.dataSource('db', {connector: 'memory'});
       const User = app.registry.createModel({