It's very, very simple, it's not 6 kata ... ;-((

I fixed that and now it's working,thanks.

What you see is a confusing message coming from Node8 tests. Please change to other version (preferrably the latest one, Node 18), and see that the reason of failing tests is different:

TypeError: Cannot read properties of null (reading 'length')
    at countSmileys (test.js:5:38)
    at doTest (test.js:17:24)
    at Context.<anonymous> (test.js:34:7)
    at process.processImmediate (node:internal/timers:471:21)

Your solution has a bug which you need to fix. I will try to take care of confusing messages.

I passed all tests in node v8 but when trie to attempt it's showing
Incorrect answer for arr=[":D" , ":~)" , ";~D" , ":)"]: expected 4 to equal 4
Incorrect answer for arr=[]: expected 0 to equal 0

any lead please.

I am almost out of Codewars and unfortunately I have no time to fix this, sorry!

Use this:

const chai = require("chai");
const assert = chai.assert;
chai.config.truncateThreshold=0;

So the error message isn't truncated when using newer Node's versions. See the issue below.

You have a trailing whitespace. To see it, select Node v8. As it is an error in your code, I'll close this issue and I'll open a new one with the proper problem.

Can any one please explain what wrong is here
expected '(A : 0) - (B : 1290) - (C : 515) - (D…' to equal '(A : 0) - (B : 1290) - (C : 515) - (D…'