How to write a function that passes this mocha test?

I have to write a function that simplifies a scope expression. I already have a set of tests to test the function. I am very new to TDD.

Here are my tests:

test('single scope simplifies to itself', function() {
  assert.equal(simplifyScopeExpression("scope:1"), "scope:1");
});  

test('AnyOf simplifies to itself', function() {
      assert.equal(
        simplifyScopeExpression({AnyOf: ["scope:1", "scope:2"]}),
        {AnyOf: ["scope:1", "scope:2"]});
    });

test('AllOf simplifies to itself', function() {
  assert.equal(
    simplifyScopeExpression({AllOf: ["scope:1", "scope:2"]}),
    {AllOf: ["scope:1", "scope:2"]});
});

Here is a function that I wrote to simplify the first test, I am not sure if its right but it passes the first test. The function should return a scope expression.

const assert = require("assert");

 exports.simplifyScopeExpression = (scope1,scope2) => {
 assert.deepEqual(scope1,scope2)
 return scope1
}