feat(typeQuery): add support for typeof of an imported module

[Pmyl]

This PR adds support to cases like this:

import * as STAR from './module1';
import REQUIRE = require('./module2');

const module1Mock: typeof STAR = createMock<typeof STAR>();
const module2Mock: typeof REQUIRE = createMock<typeof REQUIRE>();

It takes in account multiple exports, export default (with ad hoc code) and export equals.

I've also:

• added some types to make more clear what is happening with properties and signatures removing the confusion that we had before where everything was casted to a different type every few lines
• added a method to get the alias of a symbol safely (if you call the typescript method with a non-alias symbol it will fail)
• fixed a case where creating a mock of a typeof Enum was breaking the original Enum
• fixed the mock of typeof obj.method
• added some more random casting because typescript typings are weird

Please Note: the mock of a module will contain everything that is exported, even interfaces and types that are not available to use.

[uittorio]

Happy with this, just concern about declaration index access. Are you sure there are now ways to have multiple declarations in these scenarios? :)

[Pmyl]

Happy with this, just concern about declaration index access. Are you sure there are now ways to have multiple declarations in these scenarios? :)

When do you think an imported symbol could have multiple declarations? I have to be honest I don't remember the case

[Pmyl]

@uittorio I've changed the code slightly to fix a problem where a variable with inferred type of the module didn't work.

To be clear, this is the case:

import * as STAR from './module';

const moduleVariable = STAR;
createMock<typeof moduleVariable>();

I've reorganised the code a bit, I think now it makes more sense.

Let me know about the multiple declarations (comment above).

[uittorio]

Happy with this, just concern about declaration index access. Are you sure there are now ways to have multiple declarations in these scenarios? :)

When do you think an imported symbol could have multiple declarations? I have to be honest I don't remember the case

multiple declaration exists when you declare a variableDeclaration and an interfaceDeclaration with the same name

const Interface: Interface;

interface Interface {
    a: string;
}

Or when you declare multiple declaration of the same interface

interface Interface {
    a: string;
}
interface Interface {
    b: string
}

The declaration[0] in the second scenario is smart enough to get all the properties even if it doesn't look like it contains them. I just had an issue in the past that for some reason there was a variable declaration on top and I couldn't find the right declaration.

[Pmyl]

@uittorio those cases work fine for the same reason: I'm getting the declaration and then I'm sending it again to do the process cycle (a.k.a. GetDescriptor) where, if needed, it will gets all the declarations.