An compile error occured when create register instance repeatly

[mirages]

Expected Behavior

No error occured, and use the new register instance compile the .ts file once when create a new register instance to cover an old one, the old one may be created by third-party library(e.g. karma cli).

The reason for create a new register is that, I want to use a special RegisterOptions for .test.ts files.

Actual Behavior

By debugging the source code, I found that if create two register, the require.extensions[.ts] handler was nested registration by registerExtensions function twice. And the .ts file was compiled twice, the old register's output as the new register's input, then some error occured, like below:

TSError: ⨯ Unable to compile TypeScript:
error TS7022: '__awaiter' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.
2 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
......

Steps to reproduce the problem

1. First, create a test.ts for test the problem.
2. Then, create a index.js, and create two register instances directly in order to simplify the problem, then require the test.ts file.
3. Finally, run the node index.js command.

Minimal reproduction

ts-node-test

Specifications

• ts-node version: 9.0.0
• node version: 13.9.0
• TypeScript version: 4.0.5
• Operating system and version: win7-64bit

[blakeembrey]

This is currently the expected behavior. It could be changed but there's always a possibility of double registration (e.g. if you had two ts-node instances we can't de-duplicate between them). A better solution is that you can ignore or only include certain paths with each instance registered.

[mirages]

@blakeembrey What's the meaning of " ignore or only include certain paths with each instance registered"? Could you give me more details or any demo?

[blakeembrey]

There is documentation in the README here: https://github.com/TypeStrong/ts-node#cli-and-programmatic-options. It looks like there's a typo but scope and dir would work. I can make a PR to your test repo if that helps further.

[cspotcode]

The options' names have since changed, but scope and scopeDir are more clearly implemented and documented by #1367