ansi-sequence-parser

Parse ANSI escape sequences into a readable format for things like generating pretty HTML.

Install with your favourite package manager:

1pnpm install ansi-sequence-parser
2yarn add ansi-sequence-parser
3npm install ansi-sequence-parser

Parsing

Token format:

1interface ParseToken {
2  // The text content of the token
3  value: string;
4  // The foreground color
5  foreground: Color | null;
6  // The background color
7  background: Color | null;
8  // A Set of the applied decorations
9  decorations: Set<DecorationType>;
10}

Parse full input at once:

1import { parseAnsiSequences } from 'ansi-sequence-parser';
2
3const tokens = parseAnsiSequences(input);

If you want to parse your input in multiple chunks, make sure to create a parser so that you can maintain state between chunks:

1import { createAnsiSequenceParser } from 'ansi-sequence-parser';
2
3const parser = createAnsiSequenceParser();
4
5const tokensByLine = input.split(/\r?\n/).map((line) => parser.parse(line));

Colors

Colors format:

1// A named ANSI color, e.g. `magenta` or `brightBlue`
2export interface NamedColor {
3  type: 'named';
4  name: ColorName;
5}
6
7// A color-table lookup
8export interface TableColor {
9  type: 'table';
10  index: number;
11}
12
13// An RGB color
14export interface RgbColor {
15  type: 'rgb';
16  rgb: [number, number, number];
17}
18
19export type Color = NamedColor | TableColor | RgbColor;

In order to interpret all of the above color types as a hex code, you can create a color palette:

1import { parseAnsiSequences, createColorPalette } from 'ansi-sequence-parser';
2
3const tokens = parseAnsiSequences(input);
4const colorPalette = createColorPalette();
5
6for (const token of tokens) {
7  if (token.foreground) {
8    const foregroundValue = colorPalette.value(token.foreground);
9  }
10  if (token.background) {
11    const backgroundValue = colorPalette.value(token.background);
12  }
13}

You can also specify a custom named colors map:

1import { parseAnsiSequences, createColorPalette } from 'ansi-sequence-parser';
2
3const tokens = parseAnsiSequences(input);
4const colorPalette = createColorPalette({
5  black: '#000000',
6  red: '#bb0000',
7  green: '#00bb00',
8  yellow: '#bbbb00',
9  blue: '#0000bb',
10  magenta: '#ff00ff',
11  cyan: '#00bbbb',
12  white: '#eeeeee',
13  brightBlack: '#555555',
14  brightRed: '#ff5555',
15  brightGreen: '#00ff00',
16  brightYellow: '#ffff55',
17  brightBlue: '#5555ff',
18  brightMagenta: '#ff55ff',
19  brightCyan: '#55ffff',
20  brightWhite: '#ffffff',
21});

If you want to modify the default named colors map, you can import the defaultNamedColorsMap:

1import {
2  parseAnsiSequences,
3  createColorPalette,
4  defaultNamedColorsMap,
5} from 'ansi-sequence-parser';
6
7const tokens = parseAnsiSequences(input);
8const colorPalette = createColorPalette({
9  ...defaultNamedColorsMap,
10  blue: '#0000cc',
11});