navigationType in apply the history step used without a null check

[ADKaster]

What is the issue with the HTML Standard?

In #9856 @noamr added the activation API to navigation.

Part of that update was the addition of a few assertions as step 12.5 of apply the history step:

https://html.spec.whatwg.org/multipage/browsing-the-web.html#apply-the-history-step

Switch on navigationType:

"reload"

Assert: targetEntry's document state's reload pending is true.

"traverse"

Assert: targetEntry's document state's ever populated is true.

"replace"

Assert: targetEntry's step is displayedEntry's step and targetEntry's document state's ever populated is false.

"push"

Assert: targetEntry's step is displayedEntry's step + 1 and targetEntry's document state's ever populated is false.

However, the navigationType variable is passed in as a NavigationType-or-null.

Is there a standard practice for switching on or-null variables where the null state is simply ignored?

Or is there a missing update to the rest of the spec to always pass a navigation type? or a missing default value?

[domenic]

I don't think spec "switches" are defined rigorously enough to say whether they must be exhaustive or not. It's reasonable to interpret the current text as just not performing any steps when the value doesn't hit any of the cases.

However, if there is a reasonable thing to assert in the null case (which occurs for navigable creation/destruction updates), then we could add a clause there.