Add import.meta.main

[bartlomieju]

Closes #1834

I tried to move ImportMeta declaration to separate, however TS was crushing then, I'll investigate that tomorrow.

I had also test in C++, but it felt duplicated with TS test.

[kitsonk]

As this stands at the moment, it won't flow through to the runtime type library. (If you do deno --types you will see it is missing).

The interface is already a global interface (interface ImportMeta {}) as it has been reserved in the language for a long time. We need to extend this interface in the global scope, which is what happens when it is located in lib.web_assembly.d.ts file as that is simply inlined in the runtime type library, but that isn't the "right" way to do it for extending this in the long term. I think it is better that we put this directly in the globals.ts, the only problem is that we need to change ts_library_builder in the mergeGlobal function to copy over any interfaces there into the type library.

That is a bit complicated, so if you wanted to, just move it back to the web assembly library, and then I can do a follow up PR making the change to ts_library_builder. Otherwise you can try to tackle it. It should be added somewhere around here and needs to be done is iterate over any interfaces, ensuring it weeds out the special global interface and adds those to the target.

[bartlomieju]

@kitsonk actually I get:

$ deno --types | grep -i importmeta -A 3 -B 3

// @url js/lib.import_meta.d.ts

interface ImportMeta {
  url: string;
  main: boolean;
}

EDIT: Okay I reread your comment and understand the problem. Let's tackle it in another PR.

[ry]

Maybe we can add an argument to deno_mod_new() to tell if it's main...

[bartlomieju]

@ry I can then place it in ModuleInfo - ModuleInfo.main?

[ry]

@bartlomieju yes that makes sense to me

[bartlomieju]

@ry not super happy because there's a lot of bool flags passing but it got job done

[ry]

Nice work! Just a few comments.

[bartlomieju]

@ry changes applied

[ry]

Nice test!

[bartlomieju]

Thanks @ry, somehow missed that file...

[ry]

LGTM : )