use bat's --highlight-line feature, but dim rest instead of highlighting selected

README.md

use bat's --highlight-line feature, but dim rest instead of highlighting selected

example:

# dim and remove colors from unhighlighted lines
bat f.ts -H 42 | ./highlight-dim.ts

# dim colors from unhighlighted lines
bat f.ts -H 42 | ./highlight-dim.ts --keep-colors

highlight-dim.ts

#!/usr/bin/env bun

/// <reference lib="esnext" />

export {};

import stripAnsi from "strip-ansi";

const text = await Bun.stdin.text();

const keepColors = Bun.argv.includes("--keep-colors");

let lines = text.split("\n");

lines = lines.map((line) => {
  if (line.includes("\u001b[48;5;8;37m")) {
    return line.replaceAll("[48;5;8;", "[").replaceAll("\u001b[48;5;8m", "");
  }

  const indexOfPipe = line.indexOf("│");
  if (indexOfPipe < 0) return line;

  if (!/\d/.test(stripAnsi(line.slice(0, indexOfPipe)))) {
    return line;
  }

  const dimmed = keepColors
    ? line.slice(indexOfPipe + 1).replaceAll("\u001b", "\u001b[2m\u001b")
    : "\u001b[2m" + stripAnsi(line.slice(indexOfPipe + 1));

  return line.slice(0, indexOfPipe + 1) + dimmed;
});

console.log(lines.join("\n"));