Possible regression in Cypress 9.1: `TypeError: data.hasOwnProperty is not a function`

Current behavior

We’re running a series of tests against our production application using Cypress. The runner is using the cypress/browsers:node16.5.0-chrome94-ff93 Docker image. All of our tests fail with a similar stacktrace and none of the lines include our own test code. This suite runs successfully in Cypress 9.0.

Here’s the failure we get on almost all of the specs in our suite:

TypeError: data.hasOwnProperty is not a function
--
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:39:22)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:32:26)
  | at Object.deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:16:17)
  | at Encoder.encodeAsBinary (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/index.js:80:41)
  | at Encoder.encode (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/index.js:42:29)
  | at Client._packet (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io/dist/client.js:169:44)
  | at Socket.packet (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io/dist/socket.js:160:21)
  | at /root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io/dist/socket.js:274:18
  | at /root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/lib/socket-base.js:318:28
  | at tryCatcher (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/util.js:16:23)
  | at Promise._settlePromiseFromHandler (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:547:31)
  | at Promise._settlePromise (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:604:18)
  | at Promise._settlePromise0 (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:649:10)
  | at Promise._settlePromises (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:725:18)
  | at _drainQueueStep (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:93:12)
  | at _drainQueue (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:86:9)
  | at Async._drainQueues (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:102:5)
  | at Immediate.Async.drainQueues [as _onImmediate] (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:15:14)
  | at processImmediate (node:internal/timers:464:21)
  |  
  | TypeError: data.hasOwnProperty is not a function
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:39:22)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:40:32)
  | at _deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:32:26)
  | at Object.deconstructPacket (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/binary.js:16:17)
  | at Encoder.encodeAsBinary (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/index.js:80:41)
  | at Encoder.encode (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io-parser/dist/index.js:42:29)
  | at Client._packet (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io/dist/client.js:169:44)
  | at Socket.packet (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io/dist/socket.js:160:21)
  | at /root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/socket/node_modules/socket.io/dist/socket.js:274:18
  | at /root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/lib/socket-base.js:318:28
  | at tryCatcher (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/util.js:16:23)
  | at Promise._settlePromiseFromHandler (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:547:31)
  | at Promise._settlePromise (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:604:18)
  | at Promise._settlePromise0 (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:649:10)
  | at Promise._settlePromises (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/promise.js:725:18)
  | at _drainQueueStep (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:93:12)
  | at _drainQueue (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:86:9)
  | at Async._drainQueues (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:102:5)
  | at Immediate.Async.drainQueues [as _onImmediate] (/root/.cache/Cypress/9.1.0/Cypress/resources/app/packages/server/node_modules/bluebird/js/release/async.js:15:14)
  | at processImmediate (node:internal/timers:464:21)
  |  
  | [502:1124/150621.083113:ERROR:bus.cc(392)] Failed to connect to the bus: Failed to connect to socket /var/run/dbus/system_bus_socket: No such file or directory
  | [502:1124/150621.084970:ERROR:bus.cc(392)] Failed to connect to the bus: Address does not contain a colon
  | [502:1124/150621.085005:ERROR:bus.cc(392)] Failed to connect to the bus: Address does not contain a colon
  | [666:1124/150621.113215:ERROR:gpu_init.cc(453)] Passthrough is not supported, GL is swiftshader, ANGLE is

Desired behavior

We’re just looking to figure out what changed from 9.0 -> 9.1 to cause this issue. We’re able to run these tests locally, but they fail in

Test code to reproduce

  it('Home page - shows expected content', () => {
    cy.visit('/');

    cy.contains('Making millions of students better readers and writers');
  });

Our base URL is www.commonlit.org.

Cypress Version

9.1.0

Other

No response

[cexbrayat]

We do also hit this issue in v9.1. After investigation, it only appears in our projects that use @percy/cypress. Is that the case for you @geoffharcourt ?

See https://github.com/percy/percy-cypress/issues/434 for the percy/cypress issue

[Robdel12]

I spent some time digging in to try and isolate & reproduce.

describe("Breaking reproduction", function () {
  it("doesn't throw an error when making requests", function () {
    cy.then(() =>
      Cypress.backend("http:request", {
        url: "http:localhost:8001/nothing/here",
        method: "POST",
      })
    );
  });
});

This will break with the same stack trace in the OP.