using d.ts files triggers create-react-app to tell me to opt-into typescript

Created by: lifeiscontent

Is this a bug report?

Yes

Did you try recovering your dependencies?

yes

Which terms did you search for in User Guide?

typescript

Environment

Environment Info:

System: OS: macOS 10.14.3 CPU: x64 Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz Binaries: Node: 10.13.0 - ~/n/bin/node Yarn: 1.13.0 - ~/.yarn/bin/yarn npm: 6.4.1 - ~/n/bin/npm Browsers: Chrome: 71.0.3578.98 Firefox: 61.0.1 Safari: 12.0.3 npmPackages: react: ^16.8.1 => 16.8.1 react-dom: ^16.8.1 => 16.8.1 (16.7.0) react-scripts: 2.1.3 => 2.1.3 npmGlobalPackages: create-react-app: Not Found

Steps to Reproduce

(Write your steps here:)

1. create a src/utils.js and create a simple function export const clamp = (value, min, max) => Math.max(min, Math.min(value, max));
2. create s src/utils.d.ts and write the definition export function clamp(value: number, min: number, max: number): number;
3. restart server
4. watch create-react-app tell you to install typescript

Expected Behavior

I'd expect VSCode to just pick up on my .d.ts files and create-react-app wouldn't worry about it.

Actual Behavior

create-react-app interferes with .d.ts files

Reproducible Demo

(Paste the link to an example project and exact instructions to reproduce the issue.)