JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <label for="paste">Paste some text:</label>
</div>
<textarea id="paste"></textarea>

JavaScript

function diff_match_patch(){this.Diff_Timeout=1;this.Diff_EditCost=4;this.Match_Threshold=.5;this.Match_Distance=1E3;this.Patch_DeleteThreshold=.5;this.Patch_Margin=4;this.Match_MaxBits=32}var DIFF_DELETE=-1,DIFF_INSERT=1,DIFF_EQUAL=0;
diff_match_patch.prototype.diff_main=function(a,b,c,d){"undefined"==typeof d&&(d=0>=this.Diff_Timeout?Number.MAX_VALUE:(new Date).getTime()+1E3*this.Diff_Timeout);if(null==a||null==b)throw Error("Null input. (diff_main)");if(a==b)return a?[[DIFF_EQUAL,a]]:[];"undefined"==typeof c&&(c=!0);var e=c,f=this.diff_commonPrefix(a,b);c=a.substring(0,f);a=a.substring(f);b=b.substring(f);f=this.diff_commonSuffix(a,b);var g=a.substring(a.length-f);a=a.substring(0,a.length-f);b=b.substring(0,b.length-f);a=this.diff_compute_(a,
b,e,d);c&&a.unshift([DIFF_EQUAL,c]);g&&a.push([DIFF_EQUAL,g]);this.diff_cleanupMerge(a);return a};
diff_match_patch.prototype.diff_compute_=function(a,b,c,d){if(!a)return[[DIFF_INSERT,b]];if(!b)return[[DIFF_DELETE,a]];var e=a.length>b.length?a:b,f=a.length>b.length?b:a,g=e.indexOf(f);return-1!=g?(c=[[DIFF_INSERT,e.substring(0,g)],[DIFF_EQUAL,f],[DIFF_INSERT,e.substring(g+f.length)]],a.length>b.length&&(c[0][0]=c[2][0]=DIFF_DELETE),c):1==f.length?[[DIFF_DELETE,a],[DIFF_INSERT,b]]:(e=this.diff_halfMatch_(a,b))?(b=e[1],f=e[3],a=e[4],e=this.diff_main(e[0],e[2],c,d),c=this.diff_main(b,f,c,d),e.concat([[DIFF_EQUAL,
a]],c)):c&&100<a.length&&100<b.length?this.diff_lineMode_(a,b,d):this.diff_bisect_(a,b,d)};
diff_match_patch.prototype.diff_lineMode_=function(a,b,c){var d=this.diff_linesToChars_(a,b);a=d.chars1;b=d.chars2;d=d.lineArray;a=this.diff_main(a,b,!1,c);this.diff_charsToLines_(a,d);this.diff_cleanupSemantic(a);a.push([DIFF_EQUAL,""]);for(var e=d=b=0,f="",g="";b<a.length;){switch(a[b][0]){case DIFF_INSERT:e++;g+=a[b][1];break;case DIFF_DELETE:d++;f+=a[b][1];break;case...