[api extractor] support module variable and type

[adventure-yunfei (adventure-yunfei)]

Supports:

• the module variable case (when "namespaceSupport" is configured as "permissive"):

export const foo: number = 1;
export let bar: { m: boolean; } = { m: 1};

(But does not support old es5 var keywords).

• the "type" declaration case:

export type A = number;
export type B = A & { m: boolean; };

With these two cases support, at least all of the exported items are listed inside the apis (along with later api-documenter feature support).

Please let me know if this PR is proper, since these features may not be common, and seems api-extractor 7 is coming?

If the PR can be merged, I'll continue to run rush build and try to provide more test cases (I've tested with my entire project, and a demo project).

[Pete Gonzalez (octogonz)]

Please let me know if this PR is proper, since these features may not be common, and seems api-extractor 7 is coming?

adventure-yunfei (@adventure-yunfei) I've published a preliminary "beta" release of AE7. You can install it like this:

npm install -g @microsoft/api-documenter@beta
npm install -g @microsoft/api-extractor@beta

I haven't tested these scenarios completely yet, but the main plumbing for handling them is all in place.
This release is pretty rough around the edges, but we're interested in early feedback. I'll send a broader announcement once we've worked through a small punch list of final work items.

[adventure-yunfei (adventure-yunfei)]

Perfect! I'll first test against the new version.