How to run

Start the vueapp

In your first command line console: cd vueapp; yarn serve

Start the express https proxy

In your second command line console: yarn start

Issue

When you proxy the app.js file from vue-cli-service serve https->http (https://localhost:3000/api.js -> http://localhost:8080/api.js) the webpacker file will embed https://localhost:8080/ instead of http. This causes net::ERR_SSL_PROTOCOL_ERROR as the vue-cli-service serve is responding with http to an SSL connection.

Enabling https with vue-cli-service serve --https and allowing the proxy to trust it, causes a net::ERR_CERT_AUTHORITY_INVALID. While you can navigate to a vue-cli-service endpoint and manually trust the certificate—and in some cases will supress the error across sessions. This is an extra step that confuses the situation.

I have not been able to test if a proper https->http proxy will cause a mixed-mode warning.