typescript-compiler | TypeScript Compilers for Meteor | Web Framework library

I appreciate that this is likely a naive question, however I am trying to find my way in the dark and the documentation from Microsoft really isn't as intuitive as I need it to be, since I've never worked with either Visual Studio Code or TypeScript before.

• I have installed Visual Studio Code (version 1.51.1)
• Visual Studio Code > Help > About references Node.js 12.14.1 - I'm not sure if it's telling me that it has included that in its own install or if it needs that to work properly
• I have downloaded TypeScript for Visual Studio 2015 (from https://www.microsoft.com/en-us/download/details.aspx?id=48593) and successfully installed it by following the excellent and clear instructions from @Neurotransmitter

I have written and saved a basic .ts file:

Supposing we have a generic class or an interface:

I need help with Typescript-compiler understanding. I want to write a script that parse each typescript file, looking for an import declaration and if import declaration using barrel-file script should throw message about it. I dive into deep and found some solution:

There's actually a similar question out there: How do I fix typescript compiler errors on css files?

So I'm trying to import css module in typescript, like this:

I often use code like in example below and was wondering if there is some smart way to type the find results without having to do explicit type assertion.

I regularly have unit tests where I need to compare two moment objects. I'd us moment's built-in function moment.isSame(moment) to compare them. However, this means my assertion will look like this:

expect(moment1.isSame(moment2)).toBeTrue();

I didn't quite like this, especially because the failure message will be less informative. Hence, I wanted to write a custom jest matcher "toBeSameMoment". The following code seems to compile at least:

I'm getting following error in my Angular Meteor project:

I am using the latest version of Visual Studio Code. VS Code is using Typescript v3.3.3. I have installed the following packages via npm both locally (save-dev) and globally:

1. TestCafe v1.1.0
2. Core-JS v3.0.
3. TypeScript v3.4.1

I have also created a tsconfig.json file and added the property - "resolveJsonModule: true"

I have created a config.json file and it is being picked up correctly in my .ts file correctly after adding the resolveJsonModule property above -

The duplicate issue is solving a slightly different issue. This one is specific to using a type within an interface.

I'd like to use a string literal type in an interface. I'm sure that I'm a small change away from the answer to this.

Below is a simplified example of my code which shows the error.

What do I need to change to get barFunction(baz) to not have the below Typescript error?