TypeError: patterns.reduce is not a function

[MelaAxel]

Environment

• OS Version: Windows 11 Enterprise (22621.1848)
• Node.js Version: 20.3.1
• Cypress 12.16
• @cypress/grep 3.15

Actual behavior

TypeError thrown starting today after Node and package updates

Expected behavior

No error

Steps to reproduce

1. launch cypress
2. select e2e
3. error thrown

Code sample

This is our cypress.config.js:

const { defineConfig } = require('cypress');

module.exports = defineConfig({
  e2e: {
    specPattern: 'cypress/e2e/**/*cy.js',
    setupNodeEvents(on, config) {
      require('@cypress/grep/src/plugin')(config);
      return config;
    },
  },
  env: {
    grepFilterSpecs: true,
  },
});

Error Details

node_modules\fast-glob\out\utils\pattern.js:131:21
  129 | exports.isAffectDepthOfReadingPattern = isAffectDepthOfReadingPattern;
  130 | function expandPatternsWithBraceExpansion(patterns) {
> 131 |     return patterns.reduce((collection, pattern) => {
      |                     ^
  132 |         return collection.concat(expandBraceExpansion(pattern));
  133 |     }, []);
  134 | }
  135 | exports.expandPatternsWithBraceExpansion = expandPatternsWithBraceExpansion;

Stack trace

TypeError: patterns.reduce is not a function
    at Object.expandPatternsWithBraceExpansion (C:\Users\US26134\Git\WebUIAutomation\node_modules\fast-glob\out\utils\pattern.js:131:21)
    at processPatterns (C:\Users\US26134\Git\WebUIAutomation\node_modules\fast-glob\out\managers\tasks.js:27:34)
    at Object.generate (C:\Users\US26134\Git\WebUIAutomation\node_modules\fast-glob\out\managers\tasks.js:7:20)
    at getWorks (C:\Users\US26134\Git\WebUIAutomation\node_modules\fast-glob\out\index.js:91:31)
    at AsyncFunction.sync (C:\Users\US26134\Git\WebUIAutomation\node_modules\fast-glob\out\index.js:23:23)
    at AsyncFunction.module.exports.sync (C:\Users\US26134\Git\WebUIAutomation\node_modules\globby\index.js:151:42)
    at cypressGrepPlugin (C:\Users\US26134\Git\WebUIAutomation\node_modules\@cypress\grep\src\plugin.js:70:30)
    at setupNodeEvents (C:\Users\US26134\Git\WebUIAutomation\cypress.config.js:23:42)
    at C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\@packages\server\lib\plugins\child\run_plugins.js:122:14
    at tryCatcher (C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\bluebird\js\release\util.js:16:23)
    at Function.Promise.attempt.Promise.try (C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\bluebird\js\release\method.js:39:29)
    at RunPlugins.load (C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\@packages\server\lib\plugins\child\run_plugins.js:119:9)
    at RunPlugins.runSetupNodeEvents (C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\@packages\server\lib\plugins\child\run_plugins.js:59:17)
    at EventEmitter. (C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\@packages\server\lib\plugins\child\run_require_async_child.js:185:22)
    at EventEmitter.emit (node:events:511:28)
    at EventEmitter.emit (node:domain:489:12)
    at process. (C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\@packages\server\lib\plugins\util.js:33:22)
    at process.emit (node:events:511:28)
    at process.emit (node:domain:489:12)
    at process.emit.sharedData.processEmitHook.installedValue [as emit] (C:\Users\US26134\AppData\Local\Cypress\Cache\12.16.0\Cypress\resources\app\node_modules\@cspotcode\source-map-support\source-map-support.js:745:40)
    at emit (node:internal/child_process:944:14)
    at processTicksAndRejections (node:internal/process/task_queues:83:21)

[alan-agius4]

I also came across this problem but infact it was an error from my side as in the ignore option I was passing a string instead of an array of strings.

[memodi]

I am facing this error too. Until this is resolved, workaround is to fixate to particular version in package.json by adding below:

"resolutions": {
    "fast-glob": ">=3.2.9 <=3.2.12"
  }

[mrmlnc]

The public interface of this package does not support a string as the value for the ignore option since 2018 year (release). I do not consider this issue a bug in my package. It is a problem on the consumer side.

Right now the problem needs to be fixed on the cypress side.

---

Similar issues: #403

[samtsai]

The public interface of this package does not support a string as the value for the ignore option since 2018 year (release). I do not consider this issue a bug in my package. It is a problem on the consumer side.

Thanks @mrmlnc , looking into a fix: cypress-io/cypress#27231

[MelaAxel]

Thanks all! Since this is a cypress-side issue, I'll close this out and watch for an update on the ticket @samtsai mentioned

[kaiserkiwi]

Why is this a cypress-side issue? I have the same issue in a project that has nothing to to with cypress.
The moment I write "fast-glob": ">=3.2.9 <=3.2.12", in my devDependencies everything works fine.

So I would assume that Version 3.3.0 has an issue here. Can we reopen this?

[mrmlnc]

This is not a cypress problem. It is the problem of every package that does not respect the public interface of that package. The public interface of this package does not support a string as the value for the ignore option since 2018 year (release). I want to say that all this time, using a string as a value was accidental.

I am willing to modify the public interface if the number of affected packages reaches dozens. For now, I prefer to keep the current implementation for codebase cleanliness.

[kaiserkiwi]

Technically I'm on your side, but it breaks stuff with a minor version. That's usually not how it should work.

According to Semver a minor version should a minor version »add functionality in a backward compatible manner«. That's not the case here. So technically this should be 4.0.0.

But I totally understand that's not your fault, that other packages use your package in a wrong way.

[mrmlnc]

That sounds pretty compelling to me. I plan to fix this issue and postpone the major change to the next major release.

[mrmlnc]

https://github.com/mrmlnc/fast-glob/releases/tag/3.3.1