textui/ansi.test.ts

import { AnsiTerminalDisplay } from "./ansi.ts";
import { Buffer, describe, expect, it } from "./testing.ts";

describe(AnsiTerminalDisplay, () => {
  it("clears the screen", async () => {
    const stdout = new Buffer();
    const display = new AnsiTerminalDisplay(stdout);
    await display.clear();
    checkSequence(stdout, "![2J");
  });

  it("writes colored characters", async () => {
    const stdout = new Buffer();
    const display = new AnsiTerminalDisplay(stdout);
    await display.setupPalette([
      { r: 0.0, g: 0.0, b: 0.0 },
      { r: 0.5, g: 0.1, b: 1.0 },
    ]);
    await display.setChar({ x: 0, y: 0 }, { ch: "$", fg: 1, bg: 0 });
    checkSequence(stdout, "![38;2;128;26;255m![48;2;0;0;0m![1;1H$");
  });

  it("moves the cursor only when needed", async () => {
    const stdout = new Buffer();
    const display = new AnsiTerminalDisplay(stdout);
    display.forceSize({ w: 4, h: 3 });
    await display.setChar({ x: 0, y: 0 }, { ch: "a", fg: 0, bg: 0 });
    await display.setChar({ x: 1, y: 0 }, { ch: "b", fg: 0, bg: 0 });
    await display.setChar({ x: 3, y: 0 }, { ch: "c", fg: 0, bg: 0 });
    await display.setChar({ x: 0, y: 1 }, { ch: "d", fg: 0, bg: 0 });
    await display.setChar({ x: 0, y: 2 }, { ch: "e", fg: 0, bg: 0 });
    checkSequence(stdout, "![1;1Hab![1;4Hcd![3;1He");
  });
});

function checkSequence(buffer: Buffer, expected: string) {
  const decoded = new TextDecoder().decode(
    buffer.bytes().map((x) => x == 0x1B ? 0x21 : x),
  );
  expect(decoded).toEqual(expected);
}