knifecycle - npm Package Compare versions

Comparing version 1.0.5 to 1.1.0

dist/index.js

@@ -25,2 +25,3 @@ 'use strict';
 var SHUTDOWN = '$shutdown';
+var INJECT = '$inject';
 var FATAL_ERROR = '$fatalError';
@@ -31,2 +32,3 @@ var E_UNMATCHED_DEPENDENCY = 'E_UNMATCHED_DEPENDENCY';
 var E_BAD_SERVICE_PROMISE = 'E_BAD_SERVICE_PROMISE';
+var E_BAD_INJECTION = 'E_BAD_INJECTION';
 
@@ -245,3 +247,6 @@ // Constants that should use Symbol whenever possible
     value: function run(dependenciesNames) {
+      var _this2 = this;
+
       var siloContext = {
+        name: 'silo-' + Date.now(),
         servicesDescriptors: new Map(),
@@ -298,3 +303,10 @@ servicesSequence: [],
 
-      return this._initializeDependencies(siloContext, 'silo', dependenciesNames).then(function (servicesHash) {
+      // Create a provider for the special inject service
+      siloContext.servicesDescriptors.set(INJECT, {
+        servicePromise: Promise.resolve(function (dependenciesNames) {
+          return _this2._initializeDependencies(siloContext, siloContext.name, dependenciesNames, true);
+        })
+      });
+
+      return this._initializeDependencies(siloContext, siloContext.name, dependenciesNames).then(function (servicesHash) {
         debug('Handling fatal errors:', siloContext.errorsPromises);
@@ -309,2 +321,3 @@ Promise.all(siloContext.errorsPromises).catch(siloContext.throwFatalError);
      * @param  {Object}     siloContext       Current execution silo context
+     * @param  {Boolean}    injectOnly        Flag indicating if existing services only should be used
      * @param  {String}     serviceName       Service name.
@@ -317,3 +330,3 @@ * @param  {String}     serviceProvider   Service provider.
     key: '_getServiceDescriptor',
-    value: function _getServiceDescriptor(siloContext, serviceName) {
+    value: function _getServiceDescriptor(siloContext, injectOnly, serviceName) {
       var serviceDescriptor = siloContext.servicesDescriptors.get(serviceName);
@@ -325,2 +338,9 @@
 
+      // The inject service is intended to be used as a workaround for unavoidable
+      // circular dependencies. It wouldn't make sense to instanciate new services
+      // at this level so throwing an error
+      if (injectOnly) {
+        return Promise.reject(new _yerror2.default(E_BAD_INJECTION, serviceName));
+      }
+
       return this._initializeServiceDescriptor(siloContext, serviceName);
@@ -385,2 +405,3 @@ }
      * @param  {String}     servicesNames     Dependencies names.
+     * @param  {Boolean}    injectOnly        Flag indicating if existing services only should be used
      * @return {Promise}                      Service dependencies hash promise.
@@ -392,7 +413,9 @@ */
     value: function _initializeDependencies(siloContext, serviceName, servicesNames) {
-      var _this2 = this;
+      var _this3 = this;
 
+      var injectOnly = arguments.length <= 3 || arguments[3] === undefined ? false : arguments[3];
+
       debug('Initializing dependencies:', serviceName, servicesNames);
       return Promise.resolve().then(function () {
-        return Promise.all(servicesNames.map(_this2._getServiceDescriptor.bind(_this2, siloContext))).then(function (servicesDescriptors) {
+        return Promise.all(servicesNames.map(_this3._getServiceDescriptor.bind(_this3, siloContext, injectOnly))).then(function (servicesDescriptors) {
           debug('Initialized dependencies descriptors:', serviceName, servicesNames);
@@ -399,0 +422,0 @@ siloContext.servicesSequence.push(servicesNames);

dist/index.mocha.js

@@ -294,2 +294,54 @@ 'use strict';
 
+  describe('inject', function () {
+
+    it('should work with no dependencies', function (done) {
+      $.constant('ENV', ENV);
+      $.constant('time', time);
+      $.provider('hash', $.depends(['ENV'], hashProvider));
+
+      $.run(['time', 'hash', '$inject']).then(function (dependencies) {
+        _assert2.default.deepEqual(Object.keys(dependencies), ['time', 'hash', '$inject']);
+        return dependencies.$inject([]).then(function (injectDependencies) {
+          _assert2.default.deepEqual(Object.keys(injectDependencies), []);
+          _assert2.default.deepEqual(injectDependencies, {});
+
+          done();
+        });
+      }).catch(done);
+    });
+
+    it('should work with same dependencies then the running silo', function (done) {
+      $.constant('ENV', ENV);
+      $.constant('time', time);
+      $.provider('hash', $.depends(['ENV'], hashProvider));
+
+      $.run(['time', 'hash', '$inject']).then(function (dependencies) {
+        _assert2.default.deepEqual(Object.keys(dependencies), ['time', 'hash', '$inject']);
+        return dependencies.$inject(['time', 'hash']).then(function (injectDependencies) {
+          _assert2.default.deepEqual(Object.keys(injectDependencies), ['time', 'hash']);
+          _assert2.default.deepEqual(injectDependencies, {
+            hash: { ENV: ENV },
+            time: time
+          });
+
+          done();
+        });
+      }).catch(done);
+    });
+
+    it('should fail with non instanciated dependencies', function (done) {
+      $.constant('ENV', ENV);
+      $.constant('time', time);
+      $.provider('hash', $.depends(['ENV'], hashProvider));
+
+      $.run(['time', '$inject']).then(function (dependencies) {
+        _assert2.default.deepEqual(Object.keys(dependencies), ['time', '$inject']);
+        return dependencies.$inject(['time', 'hash']).catch(function (err) {
+          _assert2.default.equal(err.code, 'E_BAD_INJECTION');
+          done();
+        });
+      }).catch(done);
+    });
+  });
+
   describe('shutdown', function () {
@@ -296,0 +348,0 @@

package.json

 {
   "name": "knifecycle",
-  "version": "1.0.5",
+  "version": "1.1.0",
   "description": "Manage your NodeJS processes's lifecycle.",
@@ -5,0 +5,0 @@ "main": "dist/index.js",

README.md

@@ -20,45 +20,35 @@ # knifecycle
 Unfortunately, applications often rely on **global states** where the JavaScript
- module system show its limits. This is where `knifecycle` enters the game.
+ module system shows its limits. This is where `knifecycle` enters the game.
 
-It is largely inspired from the Angular service system except is should not
- provide code but access to global stuffs (time, filesystem, dbs). It also
- have an important additional feature to shutdown processes which is less
- useful for front-end applications and doesn't exists in Angular.
+It is largely inspired by the Angular service system except it should not
+ provide code but access to global states (time, filesystem, db). It also
+ have an important additional feature to shutdown processes which is really
+ useful for back-end servers and doesn't exists in Angular.
 
 ## Features
 - services management: start services taking their dependencies in count and
- shut them down the same way to gracefully exit.
+ shut them down the same way for graceful exits.
 - easy end to end testing: just replace your services per your own mocks and
- stubs.
+ stubs while ensuring your application integrity between testing and production.
 - isolation: isolate processing in a clean manner, per concerns.
 - functional programming ready: encapsulate global states allowing the rest of
  your application to be purely functional.
-- no circular dependencies for services: while circular dependencies is not a
+- no circular dependencies for services: while circular dependencies are not a
  problem within purely functional libraries (require allows it), it may be
- harmful for your services, knifecycle impeach that.
+ harmful for your services, knifecycle impeach that while providing an `$inject`
+ service à la Angular to allow accessing existing services references.
 
 ## Usage
 
-First we create a Knifecycle instance:
+Using Knifecycle is all about declaring the services our application need. Some
+ of them are simple constants:
 ```js
-// services/knifecycle.js
-// For this sample application, we know we won't need several lifecycle
-// instances so we will use the module singleton instead of injecting the
-// lifecycle instance everywhere.
-import Knifecycle from 'knifecycle';
-
-const $ = Knifecycle.getInstance();
-
-export default $;
-```
-
-Then we create the services our application need. Some of them are simple
- constants:
-```js
 // services/core.js
 // Core services that are often needed. The constant decorator allows you to
 // declare values or simple functions managing global states
-import { constant } from './knifecycle';
-import Winston from 'winston';
 
+// Notice we are directly using the instance module that prepare the Knifecycle
+// instance for us
+import { constant } from 'knifecycle/instance';
+
 // Add the process environment as a simple constant
@@ -84,6 +74,7 @@ constant('ENV', process.env);
  logger.
+
 ```js
 // services/logger.js
 // A log service that depends on the process environment
-import { depends, service } from './knifecycle';
+import { depends, service } from 'knifecycle/instance';
 import Logger from 'logger';
@@ -112,3 +103,3 @@
 // services/db.js
-import { depends, provider } from './knifecycle';
+import { depends, provider } from 'knifecycle/instance';
 import MongoClient from 'mongodb';
@@ -143,6 +134,6 @@
 
-Adding an express server
+Adding an Express server
 ```js
 // services/server.js
-import { depends, constant, provider, service } from './knifecycle';
+import { depends, constant, provider, service } from 'knifecycle/instance';
 import express from 'express';
@@ -209,3 +200,3 @@
 
-import { run } from './services/knifecycle';
+import { run } from 'knifecycle/instance';
 import * from './services/core';
@@ -227,3 +218,3 @@ import * from './services/log';
   // The shutdown service will disable silos progressively and then the services
-  // they rely on to finaly resolve the returned promise when done
+  // they rely on to finally resolve the returned promise once done
   .then($shutdown)
@@ -251,13 +242,14 @@ .then(() => {
 
-Use this lib for real world applications. I plan to use it with the
- [Trip Story](https://github.com/nfroidure/TripStory) toy project first and use
- it at work then. Maybe for front-end stuffs too.
+This library is already used by the microservices i am working on at 7Digital
+ but I plan to use it with the
+ [Trip Story](https://github.com/nfroidure/TripStory) toy project in order to
+ illustrate its usage on an open-source project. I think i will also use it for
+ front-end projects too.
 
 The scope of this library won't change. However the plan is:
 - improve performances
-- allow to declare singleton services
-- use next JavaScript feature that ships to Node if it make sense:
-depends, constant, service, provider may become decorators;
-WeakMap may be used to share singleton services between runs
-- track bugs
+- [allow to declare singleton services](https://github.com/nfroidure/knifecycle/issues/3)
+- evolve with Node. You will never have to transpile this library to use it with Node.
+- `depends`, `constant`, `service`, `provider` may become decorators;
+- track bugs ;)
 
@@ -264,0 +256,0 @@ I'll also share most of my own services/providers and their stubs/mocks in order

src/index.js

@@ -7,2 +7,3 @@ import YError from 'yerror';
 const SHUTDOWN = '$shutdown';
+const INJECT = '$inject';
 const FATAL_ERROR = '$fatalError';
@@ -13,2 +14,3 @@ const E_UNMATCHED_DEPENDENCY = 'E_UNMATCHED_DEPENDENCY';
 const E_BAD_SERVICE_PROMISE = 'E_BAD_SERVICE_PROMISE';
+const E_BAD_INJECTION = 'E_BAD_INJECTION';
 
@@ -217,2 +219,3 @@ // Constants that should use Symbol whenever possible
     const siloContext = {
+      name: 'silo-' + Date.now(),
       servicesDescriptors: new Map(),
@@ -274,3 +277,10 @@ servicesSequence: [],
 
-    return this._initializeDependencies(siloContext, 'silo', dependenciesNames)
+    // Create a provider for the special inject service
+    siloContext.servicesDescriptors.set(INJECT, {
+      servicePromise: Promise.resolve(dependenciesNames =>
+        this._initializeDependencies(siloContext, siloContext.name, dependenciesNames, true)
+      ),
+    });
+
+    return this._initializeDependencies(siloContext, siloContext.name, dependenciesNames)
     .then((servicesHash) => {
@@ -286,2 +296,3 @@ debug('Handling fatal errors:', siloContext.errorsPromises);
    * @param  {Object}     siloContext       Current execution silo context
+   * @param  {Boolean}    injectOnly        Flag indicating if existing services only should be used
    * @param  {String}     serviceName       Service name.
@@ -291,3 +302,3 @@ * @param  {String}     serviceProvider   Service provider.
    */
-  _getServiceDescriptor(siloContext, serviceName) {
+  _getServiceDescriptor(siloContext, injectOnly, serviceName) {
     const serviceDescriptor = siloContext.servicesDescriptors.get(serviceName);
@@ -299,2 +310,9 @@
 
+    // The inject service is intended to be used as a workaround for unavoidable
+    // circular dependencies. It wouldn't make sense to instanciate new services
+    // at this level so throwing an error
+    if(injectOnly) {
+      return Promise.reject(new YError(E_BAD_INJECTION, serviceName));
+    }
+
     return this._initializeServiceDescriptor(siloContext, serviceName);
@@ -367,5 +385,6 @@ }
    * @param  {String}     servicesNames     Dependencies names.
+   * @param  {Boolean}    injectOnly        Flag indicating if existing services only should be used
    * @return {Promise}                      Service dependencies hash promise.
    */
-  _initializeDependencies(siloContext, serviceName, servicesNames) {
+  _initializeDependencies(siloContext, serviceName, servicesNames, injectOnly = false) {
     debug('Initializing dependencies:', serviceName, servicesNames);
@@ -375,3 +394,3 @@ return Promise.resolve()
       () => Promise.all(
-        servicesNames.map(this._getServiceDescriptor.bind(this, siloContext))
+        servicesNames.map(this._getServiceDescriptor.bind(this, siloContext, injectOnly))
       )
@@ -378,0 +397,0 @@ .then((servicesDescriptors) => {

src/index.mocha.js

@@ -309,2 +309,67 @@ import assert from 'assert';
 
+  describe('inject', () => {
+
+    it('should work with no dependencies', (done) => {
+      $.constant('ENV', ENV);
+      $.constant('time', time);
+      $.provider('hash', $.depends(['ENV'], hashProvider));
+
+      $.run(['time', 'hash', '$inject'])
+      .then((dependencies) => {
+        assert.deepEqual(Object.keys(dependencies), ['time', 'hash', '$inject']);
+        return dependencies.$inject([])
+        .then((injectDependencies) => {
+          assert.deepEqual(Object.keys(injectDependencies), []);
+          assert.deepEqual(injectDependencies, {});
+
+          done();
+        });
+      })
+      .catch(done);
+
+    });
+
+    it('should work with same dependencies then the running silo', (done) => {
+      $.constant('ENV', ENV);
+      $.constant('time', time);
+      $.provider('hash', $.depends(['ENV'], hashProvider));
+
+      $.run(['time', 'hash', '$inject'])
+      .then((dependencies) => {
+        assert.deepEqual(Object.keys(dependencies), ['time', 'hash', '$inject']);
+        return dependencies.$inject(['time', 'hash'])
+        .then((injectDependencies) => {
+          assert.deepEqual(Object.keys(injectDependencies), ['time', 'hash']);
+          assert.deepEqual(injectDependencies, {
+            hash: { ENV },
+            time,
+          });
+
+          done();
+        });
+      })
+      .catch(done);
+
+    });
+
+    it('should fail with non instanciated dependencies', (done) => {
+      $.constant('ENV', ENV);
+      $.constant('time', time);
+      $.provider('hash', $.depends(['ENV'], hashProvider));
+
+      $.run(['time', '$inject'])
+      .then((dependencies) => {
+        assert.deepEqual(Object.keys(dependencies), ['time', '$inject']);
+        return dependencies.$inject(['time', 'hash'])
+        .catch((err) => {
+          assert.equal(err.code, 'E_BAD_INJECTION');
+          done();
+        });
+      })
+      .catch(done);
+
+    });
+
+  });
+
   describe('shutdown', () => {
@@ -311,0 +376,0 @@

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Found 1 instance in 1 package

Fixed alerts

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Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

80596

increased by10.12%

Number of package files

11

increased by57.14%

Lines of code

1593

increased by11.55%

Worsened metrics

Number of lines in readme file

489

decreased by-1.61%

No dependency changes