How to replace phrases in a text for a given expression in JavaScript

Question

I have wrote this function that aims to replace words or phrases in a text document with a specified expression expr given a set of tokens to be matched. The document is newline formatted.

function replaceTokens(text, tokens, expr, isline = false) {
  tokens.forEach(word => {
    if (expr[token]) {
      if (isline) { // line regex
        text = text.replace(new RegExp("(" + word.replace(/([\(\)'?*!"])/g, "\\$1") + ")", "gi"), expr);
      } else {
        text = text.replace(new RegExp("(" + word + ")", "gi"), expr[token]);
      }
    }
  });
  return text;
}

I'm facing two problems.

1) For words tokens like Lorem, qui, etc. it works pretty ok, but I cannot get rid of the whole token case i.e. I do not want to match qui within a word like quis, but only the given token in the text. Using ^word$ does not work here with capture group ^(word)$

[1 - SOLVED] according to first answer with new RegExp("\\b(" + word + ")\\b", "gi")

2) For phrases tokens, the regex I'm using does not work properly. I want to match the exact line like Lorem ipsum dolor sit amet in

Lorem ipsum dolor sit amet
Lorem ipsum dolor sit amet etwas

it should match the first line only, not the second line as well.

Here is an example. For (1) you can see how qui is captured as a token and within the word quis or aliquip.

function replaceTokens(text, tokens, expr, isline = false) {
  tokens.forEach(word => {
    if (isline) { // line regex
      text = text.replace(new RegExp("(" + word.replace(/([\(\)'?*!"])/g, "\\$1") + ")", "gi"), expr);
    } else {
      text = text.replace(new RegExp("\\b(" + word + ")\\b", "gi"), expr);
    }
  });
  return text;
}

text = "Lorem ipsum dolor sit amet,\n consectetur adipiscing elit,\nsed do eiusmod tempor incididunt\nut labore et dolore magna aliqua.\nUt enim ad minim veniam,\nquis nostrud exercitation ullamco laboris nisi\nut aliquip ex ea commodo consequat.\nDuis aute irure dolor in reprehenderit in voluptate velit esse\ncillum dolore eu fugiat nulla pariatur.\nExcepteur sint occaecat cupidatat non proident,\nLorem ipsum dolor sit amet etwas,\nsunt in culpa qui officia deserunt mollit anim id est laborum"

out = replaceTokens(text, ["Lorem", "ut", "qui"], "<strong>$1</strong>", false)
out_phrases = replaceTokens(text, ["Lorem ipsum dolor sit amet", "Duis aute irure dolor in reprehenderit"], "<strong>$1</strong>", true)
document.getElementById("in_text").innerHTML = text.replace(/\n/g, '<br/>')
document.getElementById("out_text").innerHTML = out.replace(/\n/g, '<br/>')
document.getElementById("out_phrases").innerHTML = out_phrases.replace(/\n/g, '<br/>')

<div id="in_text"></div>
<hr>
<div id="out_text"></div>
<hr>
<div id="out_phrases"></div>

Addded jsfiddle snippet to try it out.

Answer 1

The first question seems pretty clear, Wrap your Regex string in '\b' (Word boundary):

      text = text.replace(new RegExp("\\b(" + word + ")\\b", "gi"), expr);

That should match 'Whole Words only'.

The second question, here you can check, if it's start of text or it follows a dot and either the end of text or a dot after it, like this:

text = text.replace(new RegExp("(^|\\.\\s?|,\\s?)(" + word.replace(/([\(\)'?*!"])/g, "\\$1") + ")($|\\.|,)", "gi"), expr);

The idea is that it should match a SENTENCE, not a line. And a sentence either starts at the start of the string or after a dot or a comma and it ends with either a dot, a comma or at the end of the string.

You should NOT use the the 'Multiline' option.

Edit2:

I have changed the Groups, I made, to non-capturing groupd, so they don't mesh up the Groups replacement. Now it's:

text = text.replace(new RegExp("(?:^|\\.\\s?)(" + word.replace(/([\(\)'?*!"])/g, "\\$1") + ")(?:\\.|,|$)", "gi"), expr);

Now it Works on fiddle.