The issue is in your if statement because includes() returns a boolean based on the string parameter. A better way of doing this would be to use something like:

if(arr.includes("TL") && arr.includes("TM") && arr.includes("TR")) {
  console.log("yes");
}

If you have lots of elements in your array I would suggest something more along the lines of:

var flag = true;
for(i=0; i<arr.length; i++) {
  if(!arr.includes(arr[i])) {
    flag = false;
  }
}
if(flag) {
  console.log("yes");
}

You can use the .some method referenced here.

The some() method tests whether at least one element in the array passes the test implemented by the provided function.

// test cases
const str1 = 'hi hello, how do you do?';
const str2 = 'regular string';
const str3 = 'hello there';

// do the test strings contain these terms?
const conditions = ["hello", "hi", "howdy"];

// run the tests against every element in the array
const test1 = conditions.some(el => str1.includes(el));
const test2 = conditions.some(el => str2.includes(el));
// strictly check that contains 1 and only one match
const test3 = conditions.reduce((a,c) => a + str3.includes(c), 0) == 1;

// display results
console.log(`Loose matching, 2 matches "${str1}" => ${test1}`);
console.log(`Loose matching, 0 matches "${str2}" => ${test2}`);
console.log(`Exact matching, 1 matches "${str3}" => ${test3}`);

Also, as a user mentions below, it is also interesting to match "exactly one" appearance like mentioned above (and requested by OP). This can be done similarly counting the intersections with .reduce and checking later that they're equal to 1.

You can't compare objects directly, but using this method , you can compare them with JSON.stringify.

let list1 = [{
    name: "object1"
  },
  {
    name: "object2"
  },
  {
    name: "object3"
  },
  {
    name: "object4"
  }
]

var contains = list1.some(elem =>{
  return JSON.stringify({name: "object1"}) === JSON.stringify(elem);
});
if (contains) {
  document.write('contains')
} else {
  document.write('doesnt')
}

Usesome method to check whether Capulet exists in an array:

Copylet obj = { last: "Capulet" };
const isExist = whatIsInAName.some(f => f.last == obj.last)

Copyconst whatIsInAName = [
  { first: "Romeo", last: "Montague" },
  { first: "Mercutio", last: null },
  { first: "Tybalt", last: "Capulet" }
 ];

let obj = { last: "Capulet" };
const isExist = whatIsInAName.some(f => f.last == obj.last)
console.log(`Exists: ${isExist}`)

Or you can use filter to get all objects based on criteria:

Copyconst whatIsInAName = [
  { first: "Romeo", last: "Montague" },
  { first: "Mercutio", last: null },
  { first: "Tybalt", last: "Capulet" }
 ];

let obj = { last: "Capulet" };
const result = whatIsInAName.filter(f => f.last == obj.last);

console.log(result)