CascadeSelect breaks when modelValue doesn't exist in the options

[ArthurN]

Describe the bug

CascadeSelect breaks when there is no corresponding option which matches modelValue. Initial render is fine, but errors out when opening the list container:

Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'some')
    at Proxy.isOptionActive (primevue_cascadeselect.js?v=a2f30ac4:806:36)
    at option (primevue_cascadeselect.js?v=a2f30ac4:563:49)

Triage
In show() method, this line:

this.activeOptionPath = this.$filled ? this.findOptionPathByValue(this.d_value) : this.activeOptionPath;

sets activeOptionPath to undefined, which then ends up breaking later in isSelected:

isSelected(processedOption) {
    return this.activeOptionPath.some((p) => p.key === processedOption.key);
},

I'd be happy to contribute a PR with a little guidance. Should this.activeOptionPath = undefined be an acceptable state? That would mean we'd need a conditional check everywhere it's referenced (isSelected, onOptionChange, onOptionClick, etc). Or, should findOptionPathByValue return [] when no option is found? The latter seems simpler, but it's hard to know all the implications without more sufficient test coverage.

Workaround

Push an option that always matches modelValue. Hide or disable it using pt passthrough if necessary. Seems to work as expected even if that optionValue is a duplicate.

Pull Request Link

No response

Reason for not contributing a PR

• Lack of time
• Unsure how to implement the fix/feature
• Difficulty understanding the codebase
• Other

Other Reason

Lack of test coverage in the codebase

Reproducer

https://stackblitz.com/edit/evp36zku?file=src%2FApp.vue

Environment

Latest version of PV and Vue. Styled mode w/ Tailwind v3.

 "@primeuix/styled": "^0.3.2",
 "@primevue/themes": "^4.2.5",
 "primevue": "^4.2.5",
 "vue": "^3.5.13",

 "tailwindcss": "^3.4.17",
 "tailwindcss-primeui": "^0.3.4",

Vue version

3.5.13 (also reproducible on Stackblitz v3.2.45)

PrimeVue version

4.2.5

Node version

No response

Browser(s)

No response

Steps to reproduce the behavior

1. Set modelValue to something that doesn't exist in options
2. Click on CascadeSelect dropdown

Expected behavior

CascadeSelect dropdown opens with nothing selected.