Http proxy support

[ffortier]

Add a proxy configuration using http-proxy-middleware so that we can stub paths and avoid errors in the console.

[sgravrock]

This seems like a reasonable feature to have, and the code looks fine to me. But it increases the set of dependencies pretty significantly for a feature that most users aren't likely to use. I wonder if we'd be better off providing a way to let users add arbitrary middleware, e.g.:

// spec/support/jasmine-browser.js
const { createProxyMiddleware } = require('http-proxy-middleware');

module.exports = {
  middleware: {
    '/cdn': createProxyMiddleware({"target": "http://localhost:8889"})
  },
  "srcDir": "src",
  "srcFiles": ["**/*.js"],
  // ...
};

That way users who want proxy support can have it, and those who don't want it won't get the extra dependencies.

On the other hand, I haven't really thought through the implications for maintainability of letting user code add arbitrary middleware.

cc: @slackersoft

[slackersoft]

I think going the middleware route seems like the best option here. If we do that, I think the API we want here would allow the internals to turn each key-value-pair in the middleware object into a call to app.use() (https://github.com/jasmine/jasmine-browser-runner/blob/main/lib/server.js#L115) after doing a collision check for paths that we are already mapping. This means we'd be just relying on the middleware being implemented so it could just be passed along to Express.

[sgravrock]

Agreed. Closing.