Question: Setting up a project with in-memory FS + typeRoots from disk?

I’m trying to setup a project using in memory FS but need the usual consumption of node_modules/@types. Is this possible? am I doing something wrong? Is the proper way to do that is manually using the .createSourceFile method of the project?

What currently happens is that stuff like Promise.resolve(1) infers to any type.

[dsherret]

Works for me when targeting ESNext (I think the default is ES5 and that doesn’t have Promise):

> import { Project, ts } from "https://deno.land/x/ts_morph@13.0.3/mod.ts";
undefined
> const project = new Project({ useInMemoryFileSystem: true, compilerOptions: { target: ts.ScriptTarget.ESNext } });
undefined
> const sourceFile = project.createSourceFile("test.ts", "function test() { return Promise.resolve(1); }");
undefined
> sourceFile.getFunctions()[0].getReturnType().getText()
"Promise<number>"

[jasonkuhrt]

Nothing to do with ts-morph. There’s nothing much to share for posterity really, since the issue was so specific and random to my codebase.

As always thanks @dsherret amazing project!