lts/lib/internal/cli_table.js
'use strict';
const {
MathCeil,
MathMax,
ObjectPrototypeHasOwnProperty,
} = primordials;
const { getStringWidth } = require('internal/util/inspect');
// The use of Unicode characters below is the only non-comment use of non-ASCII
// Unicode characters in Node.js built-in modules. If they are ever removed or
// rewritten with \u escapes, then a test will need to be (re-)added to Node.js
// core to verify that Unicode characters work in built-ins. Otherwise,
// consumers using Unicode in _third_party_main.js will run into problems.
// Refs: https://github.com/nodejs/node/issues/10673
const tableChars = {
/* eslint-disable node-core/non-ascii-character */
middleMiddle: '─',
rowMiddle: '┼',
topRight: '┐',
topLeft: '┌',
leftMiddle: '├',
topMiddle: '┬',
bottomRight: '┘',
bottomLeft: '└',
bottomMiddle: '┴',
rightMiddle: '┤',
left: '│ ',
right: ' │',
middle: ' │ ',
/* eslint-enable node-core/non-ascii-character */
};
const renderRow = (row, columnWidths) => {
let out = tableChars.left;
for (let i = 0; i < row.length; i++) {
const cell = row[i];
const len = getStringWidth(cell);
const needed = (columnWidths[i] - len) / 2;
// round(needed) + ceil(needed) will always add up to the amount
// of spaces we need while also left justifying the output.
out += `${' '.repeat(needed)}${cell}${' '.repeat(MathCeil(needed))}`;
if (i !== row.length - 1)
out += tableChars.middle;
}
out += tableChars.right;
return out;
};
const table = (head, columns) => {
const rows = [];
const columnWidths = head.map((h) => getStringWidth(h));
const longestColumn = columns.reduce((n, a) => MathMax(n, a.length), 0);
for (let i = 0; i < head.length; i++) {
const column = columns[i];
for (let j = 0; j < longestColumn; j++) {
if (rows[j] === undefined)
rows[j] = [];
const value = rows[j][i] =
ObjectPrototypeHasOwnProperty(column, j) ? column[j] : '';
const width = columnWidths[i] || 0;
const counted = getStringWidth(value);
columnWidths[i] = MathMax(width, counted);
}
}
const divider = columnWidths.map((i) =>
tableChars.middleMiddle.repeat(i + 2));
let result = `${tableChars.topLeft}${divider.join(tableChars.topMiddle)}` +
`${tableChars.topRight}\n${renderRow(head, columnWidths)}\n` +
`${tableChars.leftMiddle}${divider.join(tableChars.rowMiddle)}` +
`${tableChars.rightMiddle}\n`;
for (const row of rows)
result += `${renderRow(row, columnWidths)}\n`;
result += `${tableChars.bottomLeft}${divider.join(tableChars.bottomMiddle)}` +
tableChars.bottomRight;
return result;
};
module.exports = table;