Button component has no default type

[pveierland]

Description

The Button component does not have a default type attribute. In e.g. react-bootstrap, the Button component by default has type set to button. Without such a default, the type will default to submit within forms, yielding the following warning when using e.g. Formik:

You submitted a Formik form using a button with an unspecified type attribute. Most browsers default button elements to type="submit". If this is not a submit button, please add type="button".

As it is normal to add multiple buttons within a form, it seems safer and more intuitive to have a default type set to button, and then explicitly specify which button to use for submission.

Steps to reproduce

1. Create page with the following form:

<form>
<Button type="submit">Submit</Button>
<Button>Recalculate<Button>
</form>

2. The second button will default to type=submit instead of type=button. Expected behavior would be that the second Button type would default to button.

Version

v35.2.0

Browser

Firefox

[iansan5653]

👍 I completely agree - setting the default type to button seems like a no-risk change to avoid some very unintuitive browser behavior. Another common case where we see this turn into bugs is with "Cancel" buttons, ie:

<form onSubmit={submitHandler}>
 {/* ... */}

 <Button onClick={cancelHandler}>Cancel</Button>
 <Button type="submit" variant="primary">Primary</Button>
</form>

Pressing "Cancel" in this form will unintentionally submit the form because the button doesn't have type="button".

In fact this is so unexpected that we've considered using a linting rule to force all buttons in Memex to have explicit type props.

[joshblack]

Opened up a quick PR here: #2807 to put it on Button itself. Curious if you all would expect it to be there or potentially at a lower-level like ButtonBase for other button-like components that might use it 👀

[pveierland]

I'd vote for adding it to ButtonBase, as otherwise the issue would still affect LinkButton, and could sneak up with future Button variants.