Open a bufname buffer with given options on the current window

import { Denops } from "../mod.ts";
import { open } from "../buffer/mod.ts";

export async function main(denops: Denops): Promise<void> {
  // Open `README.md`
  // Same as `:edit README.md`
  await open(denops, "README.md");

  // Open `LICENSE` with given options
  // Same as `:keepjumps keepalt edit ++enc=sjis ++ff=dos LICENSE`
  await open(denops, "LICENSE", {
    mods: "keepjumps keepalt",
    cmdarg: "++enc=sjis ++ff=dos",
  });
}

Use split, vsplit, tabedit, pedit, or whatever in opener attribute of the option like:

import { Denops } from "../mod.ts";
import { open } from "../buffer/mod.ts";

export async function main(denops: Denops): Promise<void> {
  await open(denops, "README.md", { opener: "split" });
}

Use a result value if you need window id, buffer number, window number, or tabpage number like:

import { Denops } from "../mod.ts";
import { open } from "../buffer/mod.ts";

export async function main(denops: Denops): Promise<void> {
  const info = await open(denops, "README.md");
  console.log("winid:", info.winid);
  console.log("bufnr:", info.bufnr);
  console.log("winnr:", info.winnr);
  console.log("tabpagenr:", info.tabpagenr);
}