TypeScript adoption has been swift and decisive. In 2019, the majority of js developers that take surveys use TypeScript.
Edit: Mea culpa. I got my numbers mixed up, or whatever source I thought I remembered just doesn’t exist. 46% in 2018 (state of js) says nothing about 2019, and is not a majority. That 46% is also backed up by a similar survey that npm ran. It’s worth adding though, I think, that js devs benefit from ts type inferencing and IDE support even if they aren’t using it directly
Edit: Mea culpa. I got my numbers mixed up, or whatever source I thought I remembered just doesn’t exist. 46% in 2018 (state of js) says nothing about 2019, and is not a majority. That 46% is also backed up by a similar survey that npm ran. It’s worth adding though, I think, that js devs benefit from ts type inferencing and IDE support even if they aren’t using it directly