75

Is it possible to redirect or capture Cypress browser log and command log to output?

I read some Cypress github issues on this topic. But I don't know how to make it work.

Basically, I want to capture all the Cypress GUI command logs in the headless non-GUI mode. If I can include browser console log will be even better. The purpose is to understand what happened when a test fails.

I use teamcity as ci. Here is an example of my build log. I want to see all the command log here too. Actually, any console.log run on the server side using cy.task is displayed in the build log. Running cy.task('log',message) is too manual. Any smarter ways?

[09:49:08][Step 1/1] 2 of 4: new actions (52s)
[09:50:00][Step 1/1] 3 of 4: new actions (52s)
[09:50:53][Step 1/1] 4 of 4: new actions (53s)
[09:51:47][Step 1/1]   (Results)
[09:51:47][Step 1/1] 
[09:51:47][Step 1/1]   ┌─────────────────────────────────────┐
[09:51:47][Step 1/1]   │ Tests:        8                     │
[09:51:47][Step 1/1]   │ Passing:      8                     │
[09:51:47][Step 1/1]   │ Failing:      0                     │
[09:51:47][Step 1/1]   │ Pending:      0                     │
[09:51:47][Step 1/1]   │ Skipped:      0                     │
[09:51:47][Step 1/1]   │ Screenshots:  0                     │
[09:51:47][Step 1/1]   │ Video:        true                  │
[09:51:47][Step 1/1]   │ Duration:     3 minutes, 38 seconds │
[09:51:47][Step 1/1]   │ Estimated:    1 minute, 8 seconds   │
[09:51:47][Step 1/1]   │ Spec Ran:     action/action_spec.js │
[09:51:47][Step 1/1]   └─────────────────────────────────────┘
Fabio Poloni
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Jake He
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  • It looks like they are trying to produce an all-encompassing feature rather than a simple hook, which is what most people seem to want. jantoebe's code [here](https://github.com/cypress-io/cypress/issues/448#issuecomment-393486805) looks promising. Might be worth asking him where he adds it in the tests. –  Aug 29 '18 at 20:47
  • How about sending client's browser log back to the server? Using jantoebe's idea of replacing `console` and somehow send the log back to node's console log. Do I need to make an endpoint to listen on a port using `cy.task`? – Jake He Aug 29 '18 at 22:02
  • Use something like this https://github.com/krakenjs/beaver-logger. It might be an overkill. – Jake He Aug 29 '18 at 22:03
  • Yes, definitely a `cy.task` to run the code into Node env. Then just fs to a file, but with some nice formatting. I am also interested in capturing the command log formatted html (not just the test) for documentation, so `document.getElementById('root').innerHTML` looks like the way to do that. –  Aug 29 '18 at 23:18
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    Please also see [cypress-failed-log](https://github.com/bahmutov/cypress-failed-log) which enumerates the commands - looks quite useful for CI scenario. –  Aug 30 '18 at 00:53

7 Answers7

94

As of Cypress 3.0.0, you can use cy.task() to access node directly and output to the node console. From the docs:

// in test
cy.task('log', 'This will be output to the terminal')
// in plugins file
on('task', {
  log (message) {
    console.log(message)
    return null
  }
})

See here for more info.

I don't know of a way to mirror the Cypress logs to the console directly, but this is at least a workable alternative.

Joshua Wade
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    Somehow this is not working for me. I'm on latest Cypress version. – Amit Kumar Gupta Sep 07 '20 at 00:45
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    @AmitKumarGupta This answer was taken directly from [the doc page for `cy.task`](https://docs.cypress.io/api/commands/task.html). If you follow the steps from the latest documentation and it doesn't work, then you may have found a bug, which you can [report on Github](https://github.com/cypress-io/cypress/issues/new). – Joshua Wade Sep 08 '20 at 15:49
25

Setting the ELECTRON_ENABLE_LOGGING environment variable to 1 will cause all Chrome internal logging to be printed to the console.

ELECTRON_ENABLE_LOGGING=1 npx cypress run

ELECTRON_ENABLE_LOGGING

Prints Chrome's internal logging to the console.

With this enabled, in addition to capturing any existing logging, this will also allow you to manually log within a test using console.log:

console.log('Response JSON: ' + json)
M. Justin
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  • Too bad that this only works when tests run in electron, and not e.g. when using chrome (`ELECTRON_ENABLE_LOGGING=1 npx cypress run --browser chrome`) – LGenzelis Dec 02 '21 at 14:41
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    @LGenzelis even with electron its not working for me – wamster Jan 15 '23 at 17:52
  • hey @wamster , check my answer. Or just go to https://www.npmjs.com/package/cypress-terminal-report. It's been a game changer for me :) – LGenzelis Jan 17 '23 at 12:59
11

FYI:

Cypress community is going to provide native support so that we don't have to do any workarounds to print the logs on non-GUI(headless) CLI.

Ongoing issue: https://github.com/cypress-io/cypress/issues/448 includes reference to 3 existing workarounds https://github.com/cypress-io/cypress/issues/448#issuecomment-613236352

Michael Freidgeim
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Pratik Patel
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8

Expanding on @Joshua-wade's answer, you can overwrite cy.log to redirect all calls to it to the log task. Just as the following:

Cypress.Commands.overwrite('log', (subject, message) => cy.task('log', message));

Note: there's a small drawback to this: when you run the test using the Test Runner, instead of seeing LOG my message in the command log, you'll see TASK log, my message. But IMHO it's negligible.

Arnon Axelrod
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  • when i try this i get `The 'task' event has not been registered in the setupNodeEvents method. You must register it before using cy.task()` - ```Cypress: 10.7.0``` – hanshenrik Jun 29 '23 at 13:47
1

I agree with Araon's approach using overwrite on the log function. Another approach, if you want to keep cy.log the default behavior, would be create a custom command. Doc here

Example: Cypress.Commands.add("printLog", (message) => { cy.task("log", {message}); })

This way you can call function printLog vs cy.task("log", {message});

InvisibleExo
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0

Disclaimer: I am the plugin author

You can capture Cypress CI GUI commands in headless mode, together with all the network requests, browser console messages and DOM tree changes using this free open-source plugin: https://github.com/currents-dev/cypress-debugger

As an alternative, you can also use a set of other well-known plugins:

agoldis
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-1
// cypress.config.js
const { defineConfig } = require("cypress");

module.exports = defineConfig({
  projectId: "cnpkrh",
  e2e: {
    setupNodeEvents(on, config) {
      on('task', {
        log(message) {
          console.log(message);
          return null;
        },
      });
    },
  },
});


// cypress/e2e/spec.cy.js
cy.task('log', 'This will be output to the terminal')
Ruan Nawe
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