infer-from-usage codefix should mark parameters as optional

[sandersn]

Search Terms

codefix infer from usage optional parameter

Suggestion

When you ask to for the infer-from-usage codefix for f:

function f(x, y) {
  return x + (y || 0)
}
f(1)

You should get function f(x: number, y?: number | undefined)

This already works in JS. You get /** @param {number | undefined} [y] */.

[sandersn]

@andy-ms points out that you might just want to see y?: number and the undefined should be dropped as well.