JSFiddle - React, Tailwind, and code Playground

by Emanuele del Grande

HTML

<div class="logo">
    <span>JS</span> <span>Spreadsheet</span>
    <div>Css powered spreadsheet</div>
</div>

<p>
Fork from <a href="https://jsfiddle.net/user/murrayju/fiddles/">Murrayu's fiddle</a>.<br />
Test on parsing values as numbers and numeric constants from strings, and parsing functions from strings.
</p>

CSS

@import url(https://fonts.googleapis.com/css2?family=Inter:wght@100;200;300;400;500;600;700;800;900&display=swap);

:root {
  --font-color: #444;
  --font-family: Inter, Roboto, Arial, Helvetica;
  --font-size: 14px;
  --font-weight: 300;
  --letter-spacing: -0.5px;
  --main-color: #607f8b; /* #4ae */
  --inner-border-width: 1px;
  --border-color: #ddd;
  --v-padding: 10px;
}


/* GENERIC STYLE */
*, *:before, *:after { margin; 0; padding: 0; box-sizing: border-box; outline: none; }
html, body {
    font: 14px var(--font-family); color: var(--font-color); line-height: 1.4em;
    font-weight: var(--font-weight); letter-spacing: var(--letter-spacing);
}
.logo { font: 42px var(--font-family); margin: 0; padding: 10px 0 0 20px; font-weight: 800; letter-spacing: -3px; white-space: nowrap; }
.logo span:first-child {
    position: relative; top: 0; left: 0; padding: 0 13px 0 10px; color: var(--main-color); background: var(--main-color); color: #fff;
    clip-path: ellipse(100% 125% at 100% 50%); z-index: 1;
}
.logo span:nth-child(2) { position: relative;top: 0; left: 0; margin: 0 0 0 -13px; background: transparent; z-index: 2; }

.logo div { font: 12px var(--font-family); padding: 0 0 0 70px; letter-spacing: -0.5px; }

/* SPREADSHEET STYLE */
table { border-collapse: collapse }
tr:nth-child(odd) { background: #eee }
td { border: 1px solid #e0e0e0; padding: 5px; font: 12px monospace; }
td:not(:first-child) { text-align: right; }
thead td { background: var(--main-color); color: #fff; }
b { color: #f03; }

JavaScript

EXPRS = [
    'parseInt(x)',
    'parseFloat(x)',
    'Number(x)',
    '+x',
    '~~x',
    'x>>>0',
    'isNaN(x)'

];

VALUES = [
    '"123"',
    '"+123"',
    '"-123"',
    '"123.45"',
    '"-123.45"',
    '"12e5"',
    '"12e-5"',
    
    '"0123"',
    '"0000123"',
    '"0b111"',
    '"0o10"',
    '"0xBABE"',
    
    '"4294967295"',
    '"123456789012345678"',
    '"12e999"',

    '""',
    '"123foo"',
    '"123.45foo"',
    '"  123   "',
    '"foo"',
    '"12e"',
    '"0b567"',
    '"0o999"',
    '"0xFUZZ"',

    '"+0"',
    '"-0"',
    '"Infinity"',
    '"+Infinity"',
    '"-Infinity"',

    'null',
    '[].undef',
    'true',
    'false',
    'Infinity',
    'NaN',

    '{}',
    '{valueOf: function(){return 42}}',
    '{toString: function(){return "56"}}',
    '{valueOf: function(){return 42}, toString: function(){return "56"}}',

];

//////

function wrap(tag, s) {
    if (s && s.join)
        s = s.join('');
    return '<' + tag + '>' + String(s) + '</' + tag + '>';
}

function table(head, rows) {
    return wrap('table', [
        wrap('thead', tr(head)),
        wrap('tbody', rows.map(tr))
    ]);
}

function tr(row) {
    return wrap('tr', row.map(function (s) {
        return wrap('td', s)
    }));
}

function val(n) {
    return n === true || Number.isNaN(n) ? wrap('b', n) : String(n);
}

var rows = VALUES.map(function (v) {
    var x = eval('(' + v + ')');
    return [v].concat(EXPRS.map(function (e) {
        return val(eval(e))
    }));
});

document.body.innerHTML += table(["x"].concat(EXPRS), rows);