Bug: Optional arguments make null values

[denizdogan]

From the Clay source code:

If the optional argument was passed, it will be present
at key name in the object returned from parse or run.
Otherwise, the object will not contain the key name.

However, it seems that the value does appear, with null as its value:

// reproduce_null.ts
import * as c from "https://deno.land/x/clay@v0.2.5/mod.ts"
console.log(
  new c.Command("tell me your name")
    .optional(
      c.string,
      "name",
      { flags: ["n", "name"], description: "the name" },
    ).run(),
)

Output:

$ deno run -A ./reproduce_null.ts -h
tell me your name

USAGE:
	 [OPTIONS]

OPTIONS:
	-n, --name <STRING>  the name

$ deno run -A ./reproduce_null.ts -n Bob
{ name: "Bob" }

$ deno run -A ./reproduce_null.ts
{ name: null }