Infinite recursion in net-stubbing/lib/server/middleware/request.js

[eirikur-grid]

Current behavior

We run our cypress tests on CircleCI, distributing the tests among several runners. Sometimes we get a failure like this one:

RangeError: Maximum call stack size exceeded
    at RegExp.get source [as source] (<anonymous>:null:null)
    at RegExp.toString (<anonymous>:null:null)
    at equalByTag (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:5786:35)
    at baseIsEqualDeep (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:3357:13)
    at baseIsEqual (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:3316:14)
    at equalObjects (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:5872:43)
    at baseIsEqualDeep (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:3375:14)
    at baseIsEqual (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:3316:14)
    at baseIsMatch (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:3433:19)
    at /root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:3603:37
    at baseFindIndex (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:816:11)
    at Function.findIndex (/root/.cache/Cypress/9.6.0/Cypress/resources/app/node_modules/lodash/lodash.js:7322:14)
    at getRouteForRequest (/root/.cache/Cypress/9.6.0/Cypress/resources/app/packages/net-stubbing/lib/server/route-matching.js:105:77)
    at populateMatchingRoutes (/root/.cache/Cypress/9.6.0/Cypress/resources/app/packages/net-stubbing/lib/server/middleware/request.js:45:67)
    at populateMatchingRoutes (/root/.cache/Cypress/9.6.0/Cypress/resources/app/packages/net-stubbing/lib/server/middleware/request.js:50:13)
    at populateMatchingRoutes (/root/.cache/Cypress/9.6.0/Cypress/resources/app/packages/net-stubbing/lib/server/middleware/request.js:50:13)
... and on and on and on

Desired behavior

Test should run without crashing

Test code to reproduce

I haven't found a reliable way to reproduce this. It's not always the same test that fails. However, the failures I've seen so far occur in tests with a beforeEach function that calls a utility method, which uses cy.intercept for a lot of our API routes.

Cypress Version

9.6.0

Other

No response

[chrisbreiding]

We'll need a reliable reproduction in order to debug this. Without that, we'll eventually have to close this issue until we can reproduce it. This does not mean that your issue is not happening - it just means that we do not have a path to move forward.

[mjhenkes]

Closing absent a reliable reproduction.

Please open a new issue with a reproducible example and link to this issue. Here are some tips for providing a Short, Self Contained, Correct, Example and our own Troubleshooting Cypress guide.

[eirikur-grid]

I've been looking at the source code and I suspect I've found the root cause.
In route-matching.ts there's a function named getRouteForRequest. It accepts an optional prevRoute object, from which to start its search. This is achieved by:

const possibleRoutes = prevRoute ? orderedRoutes.slice(_.findIndex(orderedRoutes, prevRoute) + 1) : orderedRoutes

Looking at the lodash documentation for the findIndex function, I've surmised that it performs a deep comparison of objects, matching by value rather than reference. Hence, if there are two identical routes, it will match the first one, even if prevRoute is a reference to the second one.

I don't have my work laptop with me so I'm unable to whip up a repro right now.

[eirikur-grid]

I'm working on a PR with a fix (and a test that would fail prior to the fix). Is it possible to re-open this issue or do I have to create a new one?

[cypress-bot]

Released in 10.5.0.

This comment thread has been locked. If you are still experiencing this issue after upgrading to
Cypress v10.5.0, please open a new issue.