Search for node_modules in parent directories when getting type roots.

[ghost]

Fixes #10617
Note that this only gets the nearest node_modules. It would be easy to modify this code to search for as many as possible rather than just taking the first one; would we want that?
Also, this does not get globally installed node_modules. This has a different location on different people's machines, although we could just include all possible locations and check of the ones that don't exist.
Also, @vladima is there a reason we have directoryExists optional but fileExists mandatory?

[yortus]

@Andy-MS could we make the behaviour consistent with the compiler's existing moduleResulution: node implementation? That's already present in the compiler and it searches up multiple levels (if neccessary) which matches runtime behaviour (except I think it doesn't look for global node_modules).

The existing 'searching up' implementation is in program.ts here.

I understand this is a slightly different thing, because you are not searching for a specific module, but looking for whatever you can find in a @types directory. But it's more consistent with runtime behaviour if you keep searching up and accumulate all the @types/X typings you find.

If the compiler does not search up multiple levels for @types, there are two problems that would be surprising for users:

1. it will fail to compile programs that are valid/work fine at runtime.
2. it will be internally inconsistent in that something like import * as ts from 'typescript' will search up multiple levels to find the tsc typings, but import * as fs from 'fs' will not search up multiple levels for the node typings.

[mhegazy]

👍

[mhegazy]

please port these to release-2.0 branch as well.

[fletchsod-developer]

Since this is fixed in 2.0 branch. Question is which release version at the earliest contain this fix?

[ghost]

@fletchsod-developer Works for me in 2.0.3. This isn't in 2.0.2 as that was published in before this change was made.