Optimising build duration in Cypress v10+

Improve the build duration of Cypress v10+ builds through smarter NPM dependency management.

The BrowserStack Cypress CLI reads the cypress config file for config validation and resource assignment when executing Cypress tests on BrowserStack. With Cypress version 10 and above, the config file changes from cypress.json to cypress.config.js/.ts/.cjs/.mjs. Reading the cypress.config.js/.ts/.cjs/.mjs file requires the installation of NPM dependencies defined in the file. This installation leads to increased build execution time even though BrowserStack caches all your NPM dependencies to save running npm install again.

To address this issue in Cypress version 10 and above, BrowserStack introduced the enforce_settings key within the browserstack.json file. Activating this key allows configurations such as specPattern, baseURL, video, and videoUploadOnPasses for validation to be fetched from browserstack.json (Table 2), bypassing the need to read them from the cypress.config.js file. Consequently, this modification prevents the unnecessary installation of NPM dependencies from Cypress config file, thereby reducing build time on BrowserStack.

The enforce_settings feature is available from BrowserStack CLI version 1.27 onwards.

Table 1: Details of the enforce_settings key:

Key	Accepted Values	Description
`enforce_settings`	`true`, `false` (default `false`)	Determines whether to fetch configurations (Table 2) from `browserstack.json` or `cypress.config.js`. When the key is: - Not Defined or False in `browserstack.json`: The Cypress test execution follows the existing flow, reading configurations from the `cypress.config.js`. - Set to True in `browserstack.json`: Configurations from Table 2 are fetched from `browserstack.json` instead of the `cypress.config.js`.

When enforce_settings is set to true in browserstack.json, it reads the following configurations from the browserstack.json file instead of the cypress.config.js file. Ensure to set the below capabilities in your browserstack.json file:

Table 2: Configurations read from browserstack.json

Key	Value	Cypress Config Equivalent
`specs` (mandatory)	Array of patterns (file paths or regexes) that match the spec files to run. An error occurs if not defined with `enforce_settings` as `true`.	`specPattern`
`baseUrl` (optional)	URL used as a prefix for `cy.visit()` or `cy.request()` commands’ URLs.	`baseUrl`
`video` (optional)	`true` (default). Determines if Cypress captures a video of the test runs.	`video`
`videoUploadOnPasses` (optional)	`true` (default). When turned off, only compresses and uploads videos on failures. Applicable only for Cypress 12 and below.	`videoUploadOnPasses`