我的用例如下：
- 我有 2 个 angular5 库。
- 这两个库都是从以下项目克隆的：https ://github.com/robisim74/angular-library-starter
- 我有一个由 lerna 管理的 monorepo
- 子库有一个非常简单的指令，父库需要使用它。
子库的代码
import { NgModule } from '@angular/core';
import {CommonModule} from "@angular/common";
@NgModule({
imports: [CommonModule],
declarations: [
SampleDirective
],
exports: [
SampleDirective
]
})
export class ChildModule { }
子库中指令的代码
import {Directive, PLATFORM_ID, Inject} from '@angular/core';
@Directive({
selector: '.sample'
})
export class SampleDirective {
constructor(@Inject(PLATFORM_ID) private _element: Object) {
}
}
在我安装了子模块的父级中，我正在做以下简单的单元测试
import {async, ComponentFixture, TestBed} from '@angular/core/testing';
import {Component} from '@angular/core';
import {ChildModule} from "@nz/child-lib";
@Component({
selector: 'nz-host',
template: `
<div class="sample"></div>
`
})
export class TestWrapperComponent{}
describe('injection problem', () => {
let testFixture: ComponentFixture<TestWrapperComponent>;
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [TestWrapperComponent],
imports: [ChildModule]
});
}));
beforeEach(async(() => {
testFixture = TestBed.createComponent(TestWrapperComponent);
testFixture.detectChanges();
}));
it('test', () => {
expect(true).toBe(true);
});
});
当我运行测试时，我收到以下错误：
StaticInjectorError[InjectionToken Platform ID]: NullInjectorError: No provider for InjectionToken Platform ID! 错误：StaticInjectorError[InjectionToken Platform ID]：在resolveToken（ webpack:///node_modules/@angular/core/esm5/core.js:1211:0 <- spec.bundle.js:3805:24) 在 tryResolveToken (webpack:///node_modules/@angular/core/esm5/ core.js:1153:0 <- spec.bundle.js:3747:16) 在 StaticInjector.get (webpack:///node_modules/@angular/core/esm5/core.js:1024:0 <- spec.bundle .js:3618:20) 在 resolveToken (webpack:///node_modules/@angular/core/esm5/core.js:1211:0 <- spec.bundle.js:3805:24) 在 tryResolveToken (webpack:// /node_modules/@angular/core/esm5/core.js:1153：
我的package.json是这样的：
"dependencies": {
"tslib": "^1.7.1"
},
"peerDependencies": {
"@angular/common": ">= 5.0.0",
"@angular/core": ">= 5.0.0"
},
"devDependencies": {
"@angular/animations": "5.0.0",
"@angular/common": "5.0.0",
"@angular/compiler": "5.0.0",
"@angular/compiler-cli": "5.0.0",
"@angular/core": "5.0.0",
"@angular/platform-browser": "5.0.0",
"@angular/platform-browser-dynamic": "5.0.0",
"@angular/platform-server": "5.0.0",
"@compodoc/compodoc": "1.0.3",
"@nz/child-lib": "^0.0.1",
"@types/jasmine": "2.6.2",
"@types/node": "8.0.47",
"chalk": "2.3.0",
"codelyzer": "4.0.2",
"core-js": "2.5.1",
"istanbul-instrumenter-loader": "3.0.0",
"jasmine-core": "2.8.0",
"karma": "1.7.1",
"karma-chrome-launcher": "2.2.0",
"karma-coverage-istanbul-reporter": "1.3.0",
"karma-jasmine": "1.1.0",
"karma-sourcemap-loader": "0.3.7",
"karma-spec-reporter": "0.0.31",
"karma-webpack": "2.0.5",
"reflect-metadata": "0.1.10",
"rollup": "0.50.0",
"rollup-plugin-license": "0.5.0",
"rollup-plugin-node-resolve": "3.0.0",
"rollup-plugin-sourcemaps": "0.4.2",
"rxjs": "5.5.2",
"shelljs": "0.7.8",
"source-map-loader": "0.2.3",
"ts-loader": "3.1.1",
"tslint": "5.8.0",
"tslint-angular": "1.0.0",
"typescript": "2.4.2",
"uglify-js": "3.1.6",
"webpack": "3.8.1",
"zone.js": "0.8.18"
}
即使使用以下代码模拟 PLATFORM_ID
{provide: PLATFORM_ID, useValue: 'browser'}
错误仍然存在。
包作为符号链接
我有一个新的理论，为什么它会发生在我身上。我想因为我使用lerna来管理我的包和包依赖项。而且由于我是通过lerna将子模块添加到宿主模块中的，那么lerna在宿主的节点模块中创建了子模块的符号链接。所以我的理论是，当我们使用的库是符号链接时，DI 无法识别他需要注入的内容。试图弄清楚如何使用 --preserve-symlinks 运行测试
非常感谢