contains field condition throws a TypeError when the field value is an object #15534

Bug description

A contains (or includes) field condition throws TypeError: condition.lhs.includes is not a function when the target field's value is a plain object, such as a date field in range mode ({ start, end }) or a group field. The condition doesn't just evaluate to false: the exception escapes the validator.

On 6.x (0a58bd5ff), resources/js/components/field-conditions/Validator.js, prepareLhs() only turns the value into a string when it is not an object, so that an array keeps its includes() method:

// When performing lhs.includes(), if lhs is not an object or array, cast to string.
if ((operator === 'includes' || operator === 'includes_any') && !isObject(lhs)) {
    return lhs ? lhs.toString() : '';
}

isObject is lodash's, which is true for plain objects as well as arrays, so a plain object is passed through unchanged. passesIncludesCondition() then calls includes() on it without checking:

passesIncludesCondition(condition) {
    return condition.lhs.includes(condition.rhs);
}

An array has includes(); a plain object does not.

Every other operator already declines an object rather than throwing. passesCondition() guards it explicitly before its comparison:

if (isObject(condition.lhs)) {
    return false;
}

So the intended behavior for an object operand looks like "the condition fails", and only contains/includes is missing the guard. (contains_any and includes_any don't throw here: they never call includes() on the field value.)

The same code is in the latest release, v6.34.1 (prepareLhs() line 167, the guard at line 255, passesIncludesCondition() lines 262-263).

How to reproduce

1. Add two fields to a blueprint, a date range and a field conditioned on it with contains:

   -
     handle: stay_dates
     field:
       type: date
       mode: range
   -
     handle: notes
     field:
       type: textarea
       if:
         stay_dates: 'contains 2026'

2. Give stay_dates a value, e.g. { start: '2026-01-01', end: '2026-01-05' }.

3. Evaluating notes' condition throws TypeError: condition.lhs.includes is not a function instead of returning false.

As a test in resources/js/tests/FieldConditionsValidator.test.js:

setValues({ stay_dates: { start: '2026-01-01', end: '2026-01-05' } });

expect(showFieldIf({ stay_dates: 'contains 2026' })).toBe(false);

On unchanged 6.x this throws the TypeError above.

Environment

Environment
Laravel Version: 13.24.0
PHP Version: 8.4.23
Composer Version: 2.10.2
Environment: local
Debug Mode: ENABLED
Maintenance Mode: OFF
Timezone: UTC
Locale: en

Cache
Config: NOT CACHED
Events: NOT CACHED
Routes: NOT CACHED
Views: NOT CACHED

Drivers
Broadcasting: log
Cache: file
Database: sqlite
Logs: stack / single
Mail: smtp
Queue: sync
Session: file

Storage
public/storage: NOT LINKED

Statamic
Addons: 9
License Key: Not set
Sites: 255 (names redacted)
Stache Watcher: Enabled (auto)
Static Caching: Disabled
Version: 6.26.0 PRO

Statamic Addons
el-schneider/statamic-admin-bar: 0.3.2
jacksleight/statamic-bard-mutator: 3.0.5
jacksleight/statamic-bard-texstyle: 4.1.1
mitydigital/sitemapamic: 3.5.1
statamic/eloquent-driver: 5.10.0
statamic/ssg: 4.1.0
stillat/relationships: 2.4.0
studio1902/statamic-peak-tools: 9.2.0
uams-web/wordpress-importer: 0.19.0

Statamic Eloquent Driver
Addon Settings: file
Asset Containers: file
Assets: eloquent
Blueprints: file
Collection Trees: file
Collections: file
Entries: file
Fieldsets: file
Form Submissions: file
Forms: file
Global Sets: file
Global Variables: file
Navigation Trees: file
Navigations: file
Revisions: file
Sites: file
Taxonomies: file
Terms: file
Tokens: file

Installation

Other (please explain)

Reproduced in the statamic/cms repository's own test suite rather than in a site.

Additional details

A fix that fails the condition the same way the other operators do:

passesIncludesCondition(condition) {
    if (typeof condition.lhs?.includes !== 'function') {
        return false;
    }

    return condition.lhs.includes(condition.rhs);
}