Unable to access the url of a page in NightwatchJS - selenium

Question

I have not been able to get the url during the test runs intermittently.
Let me give you the background: On clicking of a button on a page it navigates to the next page. Upon navigation first thing I would like to validate the url during my test.
Below is the snippet of code I have been using to fetch the url from the current page.
1. Native implementation of nightwatch for the url assertion
assertUrlContains(text) {
this.assert.urlContains(text);
return this;
}
2. Also, tried to fetch the url using the api.url with promise pattern.
getCurrentUrl() {
return new Promise((resolve) => {
this.api.url((result) => {
resolve(result.value);
});
});
}
Both of the approach have same issues and below is the stacktrace of the error:
SEARCH RESULTS URL: null
(node:12375) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): TypeError: Cannot read property 'indexOf' of null
(node:12375) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
✖ TypeError: Cannot read property 'indexOf' of null
Something strange I've noticed that the browser navigate to the target page but the nightwatch unable to get the url even though the page load event completes.

Answer 1

You may add an explicit wait condition after you click the button to ensure that the required page has successfully loaded. You may then use one of the following approaches to validate the URL:
Use the urlEquals API for nightwatch documented here: http://nightwatchjs.org/api#assert-urlEquals
You could execute a javascript command through your test script: window.location.href to retrieve the url of the window and save it as a string. You may then perform the assertion on this string