我想使用Inversify删除NPM模块上的硬依赖项,并将它们作为构造函数参数注入。在我试一试之前,这似乎要简单得多。
事实证明,大多数DefinitelyTyped模块都不需要导出接口,当它们这样做时,它们很少包含代表整个模块的接口。此外,在导出类时,我仍然必须手动为该类定义构造函数接口。
这意味着我必须为每个模块做这样的事情:
import * as ConcreteModule from 'module'
import { ContainerModule } from 'inversify'
export interface ModuleInstance {
// copy a ton of stuff from DefinitelyTyped repo,
// because they didn't export any interfaces
}
export interface ModuleConstructor {
new (...args: any[]): ModuleInstance
}
export const ModuleConstructorSymbol = Symbol('ModuleConstructor')
export const ModuleContainer = new ContainerModule((bind) => {
bind<ModuleConstructor>(ModuleConstructorSymbol).toConstantValue(ConcreteModule)
})
有没有办法简化其中一些?注入NPM模块需要很多开销,而且Inversify文档没有任何指导。管理所需的所有不同导入/导出的名称(接口,符号和容器)是一件痛苦的事情,需要提出某种一致的命名方案。似乎没有TypeScript支持从模块自动创建接口的某种方式,没有办法以理智的方式注入NPM包。
我想我可以使用jest的自动插件功能用于模块,但我真的不喜欢设计我的代码,使得它只能通过特定的测试框架进行单元测试。
如果我能做到这一点,似乎至少可以实现这一点:
import * as ConcreteModule from 'module'
export interface TheModule extends ConcreteModule {}
但是这只有在模块导出一个类(不是工厂)时才有效,但仍然没有真正帮助我构建器。
答案 0 :(得分:4)
以下示例演示如何将npm模块(lodash
&amp; sequelize
)注入类SomeClass
。
目录结构如下所示:
src/
├── entities
│ └── some_class.ts
├── index.ts
└── ioc
├── interfaces.ts
├── ioc.ts
└── types.
const TYPES = {
Sequelize: Symbol("Sequelize"),
Lodash: Symbol("Lodash"),
SomeClass: Symbol("SomeClass")
};
export { TYPES };
import * as sequelize from "sequelize";
import * as _ from "lodash";
export type Sequelize = typeof sequelize;
export type Lodash = typeof _;
export interface SomeClassInterface {
test(): void;
}
import { Container, ContainerModule } from "inversify";
import * as sequelize from "sequelize";
import * as _ from "lodash";
import { TYPES } from "./types";
import { Sequelize, Lodash } from "./interfaces";
import { SomeClass } from "../entities/some_class";
const thirdPartyDependencies = new ContainerModule((bind) => {
bind<Sequelize>(TYPES.Sequelize).toConstantValue(sequelize);
bind<Lodash>(TYPES.Lodash).toConstantValue(_);
// ..
});
const applicationDependencies = new ContainerModule((bind) => {
bind<SomeClass>(TYPES.SomeClass).to(SomeClass);
// ..
});
const container = new Container();
container.load(thirdPartyDependencies, applicationDependencies);
export { container };
import { Container, injectable, inject } from "inversify";
import { TYPES } from "../ioc/types";
import { Lodash, Sequelize, SomeClassInterface } from "../ioc/interfaces";
@injectable()
class SomeClass implements SomeClassInterface {
private _lodash: Lodash;
private _sequelize: Sequelize;
public constructor(
@inject(TYPES.Lodash) lodash,
@inject(TYPES.Sequelize) sequelize,
) {
this._sequelize = sequelize;
this._lodash = lodash;
}
public test() {
const sequelizeWasInjected = typeof this._sequelize.BIGINT === "function";
const lodashWasInjected = this._lodash.cloneDeep === "function";
console.log(sequelizeWasInjected); // true
console.log(lodashWasInjected); // true
}
}
export { SomeClass };
import "reflect-metadata";
import { container } from "./ioc/ioc";
import { SomeClassInterface } from "./ioc/interfaces";
import { TYPES } from "./ioc/types";
const someClassInstance = container.get<SomeClassInterface>(TYPES.SomeClass);
someClassInstance.test();
{
"name": "test",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"inversify": "^4.1.0",
"lodash": "^4.17.4",
"reflect-metadata": "^0.1.10",
"sequelize": "^3.30.4"
},
"devDependencies": {
"@types/lodash": "^4.14.63",
"@types/sequelize": "^4.0.51"
}
}
{
"compilerOptions": {
"target": "es5",
"lib": ["es6", "dom"],
"types": ["reflect-metadata"],
"module": "commonjs",
"moduleResolution": "node",
"experimentalDecorators": true,
"emitDecoratorMetadata": true
}
}
此示例现在可在inversify docs中找到。