Ionic 4 local CORS bypass for dev

Trying to POST some JSON cross-origin and getting 403 forbidden? Hate your life? Me too.

Update to original CORS post for Ionic 4: 26/11/2019

On mac, running this in terminal allows local bypassing of CORS:

open -na Google\ Chrome --args --user-data-dir= --disable-web-security --disable-site-isolation-trials

Also, the headers for Ionic 4 need to be this:

let headers = {
    "Content-Type": "application/json"
// ..., params, { headers: headers }).toPromise().then(httpResponse => {
    // ...