Angular HTTPClient header returns length of undefined error

Trying to make a simple POST call but getting the error:

TypeError: Cannot read properties of undefined (reading 'length')
at HttpHeaders.applyUpdate (http.mjs:222:27)
at http.mjs:195:58
at Array.forEach (<anonymous>)
at HttpHeaders.init (http.mjs:195:33)
at HttpHeaders.forEach (http.mjs:263:14)
at Observable._subscribe (http.mjs:2116:29)
at Observable._trySubscribe (Observable.js:37:25)
at Observable.js:31:30
at errorContext (errorContext.js:19:9)
at Observable.subscribe (Observable.js:22:21)


I'm setting the base headers and making the post request:

let headers = new HttpHeaders({'Content-Type': 'application/x-www-form-urlencoded'});
this.http.post(
'<target domain>',
{
grant_type: '<grant_type>',
code: '<code>',
redirect_uri: '<redirect_uri>',
client_id: '<client_id>'
},
{
headers
}
).subscribe({
next: (response) => {
console.log('Token response:', response);
},
error: (error) => {
console.log('error:', error);
}
});


The headers variable is just the default new HttpHeaders values with Content-Type added. It seem like it should work as expected. Am I missing something?

Continue reading...