Support creating custom assertion operator like 'should('have.text.trimmed', ...)'

[freewind]

Cypress have many assertion operators like 'eq', 'contain', 'have.text', but which is not enough for me.

E.g. I want to check a DOM element have some text but want to skip around whitespaces, I have to write:

cy.get('.cell')
  .then($cell => $cell.text().trim())
  .should('eq', 'Hello')

Since none of have.text, eq, contain really work in this case.

I want to define a custom operator like have.text.trimmed, to simplify the code to:

cy.get('.cell')
  .should('have.text.trimmed', 'Hello')

I can't find any document about it, does Cypress have a way to do it? Or add this feature?

PS: I also create a question before this issue: https://stackoverflow.com/questions/55842707/how-to-define-a-custom-assertion-operator-in-cypress/55842986

[jevors]

I would love that too. As I mentioned on stackoverflow it is possible to combine a .contains() with a regular expression. But it would still be a welcome add-on to use regular expressions inside .should()

[jennifer-shehane]

Related issues - closing as duplicate

• should('have.text', ...) should ignore leading and trailing whitespace
  should('have.text', ...) should ignore leading and trailing whitespace #3887
• Have .contains() strip new lines of targets. Have .contains() strip new lines of targets. #92
• Provide a "Cypress" way to access textContent (and/or innerText) - .text() command Provide a "Cypress" way to access textContent (and/or innerText) - .text() command #630

[freewind]

@jennifer-shehane not quite duplicate I think. Trimmed text before checking is just an example here, I care more is the ability to create custom operators

[bahmutov]

take a look at https://github.com/cypress-io/cypress-example-recipes/tree/master/examples/extending-cypress__chai-assertions - this is how to add new Chair assertions to the existing ones

We could make it simpler I guess by adding something similar to custom commands

Cypress.Assertions.add('...', )

[jennifer-shehane]

Ok, that is a broader request.

We use chai for our assertions and this is also extensible with chai plugins via these instructions:. https://github.com/cypress-io/cypress-example-recipes/tree/master/examples/extending-cypress__chai-assertions

So, I believe creating a chai plugin (or using one of the many existing ones) and including it into cypress may do the trick.

Does this satisfy the assertion extension you were looking for?

[jennifer-shehane]

@bahmutov beat me 🙃

[bahmutov]

Time zone difference 😛

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[freewind]

@jennifer-shehane Thanks for the links and I managed to create it by extending chai. I've explained the code on stackoverflow, anyone interested may see it there: https://stackoverflow.com/a/55854585/342235

[jennifer-shehane]

@freewind Awesome, and great question. I will close this issue as resolved.

[robmint]

See https://github.com/Lakitna/cypress-commands for a solution