Angular 库构建错误 : TypeError: Cannot read property 'type' of null

Question

在 Angular v6 中，当尝试构建我的库时，我遇到了一个非常非描述性的BUILD ERROR Cannot read property 'type' of null

BUILD ERROR
Cannot read property 'type' of null
TypeError: Cannot read property 'type' of null
    at /Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:15378:27
    at Array.forEach (<anonymous>)
    at removeSummaryDuplicates (/Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:15377:11)
    at TemplateParser.tryParseHtml (/Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:14806:34)
    at TemplateParser.tryParse (/Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:14799:21)
    at TemplateParser.parse (/Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:14780:27)
    at AotCompiler._parseTemplate (/Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:20483:43)
    at AotCompiler._createTypeCheckBlock (/Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:20250:23)
    at /Users/John/apps/tests/service-work/node_modules/@angular/compiler/bundles/compiler.umd.js:20220:27
    at Array.forEach (<anonymous>)

已经解决了这个问题，我发这篇文章是为了帮助其他遇到这个问题的人。

Answer 1

更新

看来我对这个问题的诊断是不正确的(时间太久了，我记不清我是如何修复它的了)。 Check out this issue in the Angular repo对于听起来像是正确诊断的内容，

原答案:

经过大量调试，我想通了:

我的自定义库，暂且称之为库 A，将另一个自定义库，即库 B，导入到库 A 的 NgModule 中。库 B 从它的主要 NgModule 导出几个组件和模块。问题是，虽然库 B 从它的 NgModule 导出组件和模块，但我未能也通过 javascript/typescript 导出这些组件和模块。解决方案是确保通过我在 NgModule 中导出的 typescript 导出任何组件/模块。

示例问题代码

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { LibraryBComponent } from './library-b.component';

@NgModule({
  imports: [CommonModule],
  declarations: [LibraryBComponent],
  exports: [LibraryBComponent],
})
export class LibraryBModule {}

解决方案代码

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { LibraryBComponent } from './library-b.component';

export { LibraryBComponent }      // <-- addition

@NgModule({
  imports: [CommonModule],
  declarations: [LibraryBComponent],
  exports: [LibraryBComponent],
})
export class LibraryBModule {}