Provide .get(), .set() helpers, refactor config

index.js

@@ -26,7 +26,7 @@ module.exports = class TrailsApp extends events.EventEmitter {
     }
 
     this.pkg = app.pkg
-    this.config = lib.Trails.assignConfigDefaults(app.config)
+    this.config = new lib.Config(app.config)
     this.api = app.api
     this.bound = false
     this.started = false

lib/config.js

@@ -0,0 +1,79 @@
+'use strict'
+
+const path = require('path')
+const _ = {
+  get: require('lodash.get'),
+  set: require('lodash.set')
+}
+
+module.exports = class Config {
+
+  /**
+   * Assign default configuration values to an object
+   *
+   * @param     {Object?}     config      Object onto which the defaults should be assigned
+   * @return    {Object}                  The object, modified to have all the defaults
+   */
+  static defaults(config) {
+    config = config || {}
+
+    if (!_.get(config, 'log')) {
+      _.set(config, 'log', {})
+    }
+
+    if (!_.get(config, `env.${process.env.NODE_ENV}`)) {
+      _.set(config, `env.${process.env.NODE_ENV}`, {})
+    }
+
+    if (!_.get(config, 'main.packs')) {
+      _.set(config, 'main.packs', [])
+    }
+
+    if (!_.get(config, 'main.maxListeners')) {
+      _.set(config, 'main.maxListeners', 128)
+    }
+
+    if (!_.get(config, 'main.paths.root')) {
+      _.set(config, 'main.paths.root', path.resolve(process.cwd()))
+    }
+
+    if (!_.get(config, 'main.paths.temp')) {
+      _.set(config, 'main.paths.temp', path.resolve(_.get(config, 'main.paths.root'), '.tmp'))
+    }
+
+    return config
+  }
+
+
+  /**
+   * Create a new instance, optionally merging config values into it
+   *
+   * @param     {Object?}    values    Optional values to merge into the Config
+   */
+  constructor (values) {
+    Object.assign(this, values)
+    Config.defaults(this)
+  }
+
+  /**
+   * Safely retrieve configuration properties
+   *
+   * @param     {String}    property        The path of the configuration value to retrieve
+   * @param     {Mixed}     defaultValue    If the property does not exist, use this as default
+   * @return    {Mixed}                     The property's value, `undefined` if it does not exist
+   */
+  get(property, defaultValue) {
+    return _.get(this, property, defaultValue)
+  }
+
+  /**
+   * Safely set configuration properties
+   *
+   * @param     {String}    property        The path of the configuration value to set
+   * @param     {Mixed}     value           Value to set the property to
+   * @return    {Mixed}                     The value set
+   */
+  set(property, value) {
+    return _.set(this, property, value)
+  }
+}

lib/index.js

@@ -1,3 +1,4 @@
 exports.i18n = require('./i18n')
 exports.Trailpack = require('./trailpack')
 exports.Trails = require('./trails')
+exports.Config = require('./config')

lib/trails.js

@@ -1,46 +1,7 @@
 'use strict'
 
-const path = require('path')
-
 const TrailsUtil = module.exports = {
 
-  assignConfigDefaults (config) {
-    if (!config) {
-      config = { }
-    }
-    if (!config.env) {
-      config.env = { }
-    }
-    if (!config.env[process.env.NODE_ENV]) {
-      config.env[process.env.NODE_ENV] = { }
-    }
-    if (!config.main) {
-      config.main = { }
-    }
-    if (!config.main.packs) {
-      config.main.packs = [ ]
-    }
-    if (!config.main.paths) {
-      config.main.paths = { }
-    }
-    if (!config.main.maxListeners) {
-      config.main.maxListeners = 128
-    }
-    if (!config.log) {
-      config.log = { }
-    }
-
-    if (!config.main.paths.root) {
-      config.main.paths.root = path.resolve(process.cwd())
-    }
-
-    if (!config.main.paths.temp) {
-      config.main.paths.temp = path.resolve(process.cwd(), '.tmp')
-    }
-
-    return config
-  },
-
   /**
    * Bind listeners various application events
    */

package.json

@@ -56,7 +56,10 @@
     "url": "https://github.com/trailsjs/trails/issues"
   },
   "homepage": "http://trailsjs.io",
-  "dependencies": {},
+  "dependencies": {
+    "lodash.get": "^4.1.2",
+    "lodash.set": "^4.0.1"
+  },
   "devDependencies": {
     "eslint": "^2.0.0-beta.2",
     "eslint-config-trails": "^1.0",

test/index.js

@@ -6,6 +6,58 @@ const testAppDefinition = require('./testapp')
 
 describe('Trails', () => {
   describe('@TrailsApp', () => {
+    describe('config', () => {
+      let app
+
+      before(() => {
+        app = new TrailsApp(testAppDefinition)
+      })
+
+      describe('.get() helper', () => {
+        it('should exist', () => {
+          assert('get' in app.config, 'config.get() is not defined')
+          assert.equal(typeof app.config.get, 'function')
+        })
+
+        it('should not be enumerable', () => {
+          assert(!('get' in Object.keys(app.config)), 'config.get() should not be enumerable')
+        })
+
+        it('should return value at given property path', () => {
+          const property = app.config.get('main.paths.root')
+
+          // Not asserting actual string value because the path can change any time
+          // Having a string instead of undefined is good enough indicator that it works
+          assert.equal(typeof property, 'string')
+        })
+
+        it('should return undefined for non-existent properties', () => {
+          const property = app.config.get('just.some.random.stuff')
+
+          assert.equal(property, undefined)
+        })
+      })
+
+      describe('.set() helper', () => {
+        it('should exist', () => {
+          assert('set' in app.config, 'config.set() is not defined')
+          assert.equal(typeof app.config.set, 'function')
+        })
+
+        it('should not be enumerable', () => {
+          assert(!('set' in Object.keys(app.config)), 'config.set() should not be enumerable')
+        })
+
+        it('should set the value at given path', () => {
+          const value = { test: true }
+
+          app.config.set('some.location', value)
+
+          assert.equal(app.config.some.location, value)
+        })
+      })
+    })
+
     describe('idempotence', () => {
       it('should be able to start and stop many instances in a single node process', () => {
         let cycles = [ ]