Use another overload signature's documented info if exact one's info is missing

[falsandtru]

TypeScript Version: 3.0.0-dev.20180522

Search Terms:

Code

/**
 * A
 */
function f(a: 0): void;
function f(a: number): void;
function f(a: number) {
}
f(1);

Expected behavior:

f(1) has documented info A.

Actual behavior:

f(1) has no documented info.

Playground Link:

Related Issues:

[mhegazy]

PRs welcomed.

[ajafff]

This needs a little more thought than the opening post describes:
Does it only use the description or tags as well?
Should it only look at other signatures if the current signature has no jsdoc comment at all?
How should @param tags of other signatures be handled?
This may be kind of a braking change if it also uses @deprecated tag of another signature.

[sandersn]

Duplicate of #407