dotnet.js

function hasDotNet(text) {
  return text.match(/.NET|[\s^]\.net/) !== null;
}

function test(expected, text) {
  let rv = hasDotNet(text);
  if (expected !== rv) {
    console.log(`expected ${expected}, but got ${rv} = ${text}`);
  } else {
    console.log(`✅ ${rv} = ${text}`);
  }
}

test(true, "i love .net");
test(true, "i love .NET");
test(false, "i dislike viruses.net");

output.txt

node dotnet.js
✅ true = i love .net
✅ true = i love .NET
✅ false = i dislike viruses.net