- Dependency injection for nodejs >= v4.0.0
- Path aliases
- Dynamic module definitions
- Module mocking for easier testing
Usage of older version presentation on MNUG bounded to MVCJS.
Example of CMS app on older version.
Dependency injection provides you ioc and great testing features. Module returns single instance of dependency injection.
While using di-node, do not load anything via require, except di-node otherwise you will not be able to mock that object or provide custom implementation of that object when it's needed.
VERY IMPORTANT is to pass local require resolver to correctly resolve dependencies
let DI = require('di-node');
let di = new DI(require);
/// do something here
di.setAlias('mypath', __dirname + '/mypath');
module.exports = di;
let di = require('./di');
let Type = di.load('typed-js');
let fs = di.load('fs');
class D extends Type {
constructor(name) {
super(
{
name: Type.STRING
}
);
this.name = name;
}
}
module.exports = new D('Igor');
it('mock', () => {
class A {
constructor(config) {
expect(config).toEqual({name: 'str'});
}
}
A.STRING = 'str';
di.setAlias('b', __dirname + '/b');
let val = di.load('@{b}/di-test');
expect(val instanceof Type).toBe(true);
let valMock = di.mock('@{b}/di-test', {
'typed-js': A
});
expect(valMock instanceof A).toBe(true);
});
While using di-node do not load anything via require except di-node otherwise you will not be able to mock that object or provide custom implementation of that object when it's needed.
'use strict';
let di = require('./di');
let Type = di.load('typed-js');
let fs = di.load('fs');
class D extends Type {
constructor(name) {
super(
{
name: Type.STRING
}
);
this.name = name;
}
}
Because you will not be able to mock fs when it's needed
'use strict';
let di = require('./di');
let Type = di.load('typed-js');
let fs = require('fs');
class D extends Type {
constructor(name) {
super(
{
name: Type.STRING
}
);
this.name = name;
}
}
Mock is used for testing purposes {string} module {Object} definition of modules
it('mock', () => {
class A {
constructor(config) {
expect(config).toEqual({name: 'str'});
}
}
A.STRING = 'str';
di.setAlias('b', __dirname + '/b');
let val = di.load('@{b}/di-test');
expect(val instanceof Type).toBe(true);
let valMock = di.mock('@{b}/di-test', {
'typed-js': A
});
expect(valMock instanceof A).toBe(true);
});
Sets specific path alias which can be used in load method {string} key {string} value
// set aliases
di.setAlias('app', __dirname + '/app');
di.setAlias('components', '@{app}/components');
// usage
di.load('@{app}/module');
di.load('@{components}/redis');
Get specific alias {string} key return {string}
di.setAlias('app', __dirname + '/app');
di.getAlias('app'); // returns __dirname/app
Check if alias is setted return {boolean}
di.setAlias('app', __dirname + '/app');
di.hasAlias('app'); // true
Normalize path return {string}
di.setAlias('app', '/app');
di.setAlias('components', '@{app}/components');
di.normalize('@{components}/path'); // returns /app/components/path
Set specific module {string} key {Object|Any} value
// My fs implementation
di.setModule('fs', {
readFileSync: {
}
});
di.setModule('app/info', '@{app}/core/info');
// usage
di.load('fs'); // will load custom implementation
di.load('app/info'); // will load appPath/core/info.js
Get specific module {string} key return {Object|Any} value
di.setModule('fs', {
readFileSync: {
}
});
di.getModule('fs'); // returns custom fs module
Check if module is registered in di return {boolean}
di.setModule('custom', {
readFileSync: {
}
});
di.hasModule('custom'); // true