如何避免“未找到模块":错误:引用外部打字稿文件时无法解决"tslib"错误? [英] How to avoid "Module not found: Error: Can't resolve 'tslib'"-error when referencing an external typescript file?

问题描述

我有一个客户端/服务器应用程序，其中客户端是一个有角度的应用程序.服务器确实为其提供的API提供了几个typescript定义.这些定义是从项目外部文件夹加载的.到目前为止，这工作正常，但是现在我从Angular 7升级到Angular 8(并且还将Typescript从3.1版升级到3.5)，并且当尝试从定义中使用非静态枚举时，现在会产生此错误:

I have a client/server application, where the client is an angular-app. The server does provide a couple of typescript-definitions for the API it provides. These definitions are loaded from a project-external folder. So far this worked fine, however now I am upgrading from Angular 7 to Angular 8 (and with that also upgrading Typescript from Version 3.1 to 3.5) and when trying to use a non-static enum from the definitions, this now produces this error:

未找到模块:错误:无法解析'/path/to/server/definitions'中的'tslib'

Module not found: Error: Can't resolve 'tslib' in '/path/to/server/definitions'

当api.ts文件位于client-dir中时，一切正常.

When the api.ts-file is located within the client-dir, then everything works just fine.

为什么会这样，我该怎么办?

这是一个快速脚本，可创建一个最小的示例来重现:

Here is a quick script to create a minimal example to reproduce:

mkdir project
cd project
ng new client --minimal=true --skipGit=true --routing=false --style=css
mkdir server
echo 'export enum ApiSample { X = "X" }' > server/api.ts
sed -i 's/"compilerOptions": {/"compilerOptions": {"paths":{"api":["..\/server\/api"]},/' client/tsconfig.json
sed -i -e "1iimport { ApiSample } from 'api';" -e "s/title = 'client';/title = 'client' + ApiSample.X;/" client/src/app/app.component.ts
cd client
npm start

或者，或者手动创建示例:

Or, alternatively, to create an example manually:

1. 创建一个新的角度项目
2. 在文件系统中的某个位置创建内容为export enum ApiSample { X = "X" }
的文件"api.ts"
3. 在"tsconfig.json"中，将{"paths":{"api":["/path/to/server/api"]}添加到compilerOptions
4. 从角度项目的任何文件访问ApiSample.X
5. 运行npm start

1. Create a new angular project
2. Create somewhere in the filesystem a file "api.ts" with the content export enum ApiSample { X = "X" }
3. In the "tsconfig.json" Add {"paths":{"api":["/path/to/server/api"]} to the compilerOptions
4. Access the ApiSample.X from any file of the angular project
5. Run npm start

到目前为止的发现

• 迁移者在tsconfig.json中添加了"importHelpers": true.这就是为什么它以前起作用而现在不再起作用.在tsconfig.json中指定"importHelpers": false可以解决此问题，但是当然存在此选项是有原因的，因此这不是最终解决方案
• 明确指定"tslib": ["node_modules/tslib"]可解决此问题.这可能是最终的解决方案，尽管了解确切发生的情况以及在何处记录下来会很有趣.

Findings so far

• The migrator added "importHelpers": true in tsconfig.json. That is why it worked before and is not working anymore now. Specifying "importHelpers": false in tsconfig.json fixes the issue, but of course this option is there for a reason, so that is no final solution
• Explicitly specifying "tslib": ["node_modules/tslib"] fixes the problem. This may be a final solution although it would be interesting to know what is exactly happening and where this is documented.

推荐答案

Angular 8& 9

因此对于Angular 8和Angular 9，似乎在tsconfig.json中将"tslib": ["node_modules/tslib"]添加到compilerOptions/paths确实可以解决问题.

Angular 8&9

So for Angular 8 and 9 it seem that adding "tslib": ["node_modules/tslib"] to compilerOptions/paths in the tsconfig.json does solve the problem.

在Angular 10中，问题完全消失了，不再需要任何解决方法.

In Angular 10 the problem disappeared altogether, no workaround is needed anymore.

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