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Diffstat (limited to 'node_modules/slice-ansi/index.js')
| -rwxr-xr-x | node_modules/slice-ansi/index.js | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/node_modules/slice-ansi/index.js b/node_modules/slice-ansi/index.js new file mode 100755 index 00000000..634ee9c7 --- /dev/null +++ b/node_modules/slice-ansi/index.js @@ -0,0 +1,88 @@ +'use strict'; +const isFullwidthCodePoint = require('is-fullwidth-code-point'); + +const ESCAPES = [ + '\u001B', + '\u009B' +]; + +const END_CODE = 39; +const ASTRAL_REGEX = /[\uD800-\uDBFF][\uDC00-\uDFFF]/; + +const ESCAPE_CODES = new Map([ + [0, 0], + [1, 22], + [2, 22], + [3, 23], + [4, 24], + [7, 27], + [8, 28], + [9, 29], + [30, 39], + [31, 39], + [32, 39], + [33, 39], + [34, 39], + [35, 39], + [36, 39], + [37, 39], + [90, 39], + [40, 49], + [41, 49], + [42, 49], + [43, 49], + [44, 49], + [45, 49], + [46, 49], + [47, 49] +]); + +const wrapAnsi = code => `${ESCAPES[0]}[${code}m`; + +module.exports = (str, begin, end) => { + const arr = Array.from(str.normalize()); + + end = typeof end === 'number' ? end : arr.length; + + let insideEscape = false; + let escapeCode; + let visible = 0; + let output = ''; + + for (const item of arr.entries()) { + const i = item[0]; + const x = item[1]; + + let leftEscape = false; + + if (ESCAPES.indexOf(x) !== -1) { + insideEscape = true; + const code = /\d[^m]*/.exec(str.slice(i, i + 4)); + escapeCode = code === END_CODE ? null : code; + } else if (insideEscape && x === 'm') { + insideEscape = false; + leftEscape = true; + } + + if (!insideEscape && !leftEscape) { + ++visible; + } + + if (!ASTRAL_REGEX.test(x) && isFullwidthCodePoint(x.codePointAt())) { + ++visible; + } + + if (visible > begin && visible <= end) { + output += x; + } else if (visible === begin && !insideEscape && escapeCode !== undefined && escapeCode !== END_CODE) { + output += wrapAnsi(escapeCode); + } else if (visible >= end) { + if (escapeCode !== undefined) { + output += wrapAnsi(ESCAPE_CODES.get(parseInt(escapeCode, 10)) || END_CODE); + } + break; + } + } + + return output; +}; |
