nstdlib-nightly/lib/internal/cli_table.mjs

Node.js standard library converted to runtime-agnostic ES modules.

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/internal/cli_table.js

import { getStringWidth } from "nstdlib/lib/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.
// 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;
    // round(needed) + ceil(needed) will always add up to the amount
    // of spaces we need while also left justifying the output.
    out += cell + String.prototype.repeat.call(" ", Math.ceil(needed));
    if (i !== row.length - 1) out += tableChars.middle;
  }
  out += tableChars.right;
  return out;
};

const table = (head, columns) => {
  const rows = [];
  const columnWidths = Array.prototype.map.call(head, (h) => getStringWidth(h));
  const longestColumn = MathMaxApply(
    Array.prototype.map.call(columns, (a) => a.length),
  );

  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] = Object.prototype.hasOwnProperty.call(
        column,
        j,
      )
        ? column[j]
        : "");
      const width = columnWidths[i] || 0;
      const counted = getStringWidth(value);
      columnWidths[i] = Math.max(width, counted);
    }
  }

  const divider = Array.prototype.map.call(columnWidths, (i) =>
    String.prototype.repeat.call(tableChars.middleMiddle, i + 2),
  );

  let result =
    tableChars.topLeft +
    Array.prototype.join.call(divider, tableChars.topMiddle) +
    tableChars.topRight +
    "\n" +
    renderRow(head, columnWidths) +
    "\n" +
    tableChars.leftMiddle +
    Array.prototype.join.call(divider, tableChars.rowMiddle) +
    tableChars.rightMiddle +
    "\n";

  for (const row of rows) result += `${renderRow(row, columnWidths)}\n`;

  result +=
    tableChars.bottomLeft +
    Array.prototype.join.call(divider, tableChars.bottomMiddle) +
    tableChars.bottomRight;

  return result;
};

export default table;