Protractor: element.getText() returns an object and not String

getText() returns a promise, you need to resolve it:

page.clientRowName.getText().then(function (text) {
    console.log(text);
});

Or, if you just want to assert the text, let expect() resolve the promise for you:

expect(page.clientRowName.getText()).toEqual("ABC");

Promises and the Control Flow documentation page should clear things up.

Another solution may be to use async/await.

class Page {
  constructor() {
    this.clientRowName = $('#CLIENT_NAME');
  }
}

/****************/

it('should console.log client name', async () => {
  const client = await Page.clientRowName.getText();
  console.log(client);
});