Error trying to get attribute from element in Cypress

I have this HTML element:

<input id="" type="text" name="last_name" value="Userc7bff2d0-7faf-11e8-9884-8fe4c5df7f77-Updated" class="medium" maxlength="2000" autocomplete="off" tabindex="" data-reactid=".0.2.0.1.0.2.1.0.1.0.0.1:0.1.0.1.2:$/=10">

I want to get it's value property to assert that it has been updated by my test.

I have tried using its():

cy
  .get(selector)
  .its("value")
  .should("contain", "-Updated");

But get the error:

CypressError: Timed out retrying: cy.its() errored because the property: 'value' does not exist on your subject.

I have also tried invoke:

cy
  .get(selector)
  .invoke("value")
  .should("contain", "-Updated");

But get a similar error:

CypressError: Timed out retrying: cy.invoke() errored because the property: 'value' does not exist on your subject.

In both cases, the Cypress console output of the get() command shows the element with its value property successfully:

Yielded: input id="" type="text" name="first_name" value="Fake-Updated" class="medium" maxlength="2000" autocomplete="off" tabindex="" data- reactid=".0.2.0.1.0.2.1.0.1.0.0.1:0.1.0.0.2:$/=10"

I'm kind of stumped on this one. Please let me know if you want more info or have an idea what's going on.

invoke() calls a jquery function on the element. To get the value of an input, use the function val():

cy.get('input').invoke('val').should('contain', 'mytext')

This is not the same as getting the value attribute which will not update with user input, it only presets the value when the element renders. To get an attribute, you can use the jquery function attr():

cy.get('input').invoke('attr', 'placeholder').should('contain', 'username')

you can use this

cy.get('a') // yields the element
  .should('have.attr', 'href') // yields the "href" attribute
  .and('equal', '/home') // checks the "href" value

or

cy.get('a').should('have.attr', 'href', '/home')

for more details check this: https://docs.cypress.io/api/commands/should#Method-and-Value