Parse Vim's buffer name and return a Bufname instance.

It throws errors when a given bufname is not valid Vim's buffer name. For example, if it contains unusable characters ("<>|?*).

import { assertEquals } from "https://deno.land/std@0.192.0/testing/asserts.ts";
import { parse } from "../bufname/mod.ts";

assertEquals(
  parse("denops:///Users/John Titor/test.git"),
  {
    scheme: "denops",
    expr: "/Users/John Titor/test.git",
  },
);

assertEquals(
  parse("denops:///Users/John Titor/test.git;foo=foo&bar=bar1&bar=bar2"),
  {
    scheme: "denops",
    expr: "/Users/John Titor/test.git",
    params: {
      foo: "foo",
      bar: ["bar1", "bar2"],
    },
  },
);

assertEquals(
  parse("denops:///Users/John Titor/test.git#README.md"),
  {
    scheme: "denops",
    expr: "/Users/John Titor/test.git",
    fragment: "README.md",
  },
);

assertEquals(
  parse(
    "denops:///Users/John Titor/test.git;foo=foo&bar=bar1&bar=bar2#README.md",
  ),
  {
    scheme: "denops",
    expr: "/Users/John Titor/test.git",
    params: {
      foo: "foo",
      bar: ["bar1", "bar2"],
    },
    fragment: "README.md",
  },
);

This function does not handle path separator differences among platforms. That's why it's recommended to restore the expr with fromFileUrl after if a buffer name was constructed from a real path. For example

import { assertEquals } from "https://deno.land/std@0.192.0/testing/asserts.ts";
import * as path from "https://deno.land/std/path/mod.ts";
import { parse } from "../bufname/mod.ts";

const bufname = parse("denops:///C:/Users/John%2520Titor/test.git");
assertEquals(bufname, {
  scheme: "denops",
  expr: "/C:/Users/John%20Titor/test.git",
});
// NOTE:
// Works only on Windows (Use path.win32.fromFileUrl instead on other platforms)
assertEquals(
  path.fromFileUrl(`file://${bufname.expr}`),
  "C:\\Users\\John Titor\\test.git",
);