Found HTTP 431 (Request Header Fields Too Large) when stubbing XHR request on Cypress 3.6.0

Current behavior:

Cypress returns HTTP 431 (Request Header Fields Too Large) when stubbing response with cy.route() command.

After deep down to check my XHR request, it sends only 2 fields in request headers which are Accept: "application/json, text/plain, */* and Authorization: Bearer <token> The request URL is matched with wildcard pattern e.g. http://localhost/api/artist/*

Desired behavior:

cy.route() should return stubbed data and http status as configured in the command.

Steps to reproduce: (app code and test code)

App code just send a request with axios.get('url');

Test code stub that url with cy.route() command like this:

cy.fixture('path/to/fixture/response_body.json').then(resp => {
   cy.route({
       method: 'GET',
      url: <url with wildcard matched>,
      status: 200,
      response: resp 
   })
})

Run with Chrome 78

Versions

Cypress 3.6.0 Node 8.16.2

I try the workaround by adding NODE_OPTIONS=--max-http-header-size=1000000 before executing cypress run. it works properly.

[case12]

Seeing the same. Status 431 on a request with a long Authorization key in the header. Fixed by passing NODE_OPTIONS=--max-http-header-size=1000000

[flotwig]

@case12 Upgrade to Cypress 4.3.0 or later, this was fixed in #5988 - the default --max-http-header-size in Cypress is now 1MB

The OP should also be resolved.