Custom post type editor working

[karan4word]

After updating to the latest WordPress version 6.6.1
Its gives error :

 TypeError: n?.icon?.startsWith is not a function
    at https://domainname.gov.uk/wp-includes/js/dist/editor.min.js?ver=8607251058f984a77c8f:7:56973
    at r (https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:2:9528)
    at Proxy.r (https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:2:16845)
    at https://domainname.gov.uk/wp-includes/js/dist/editor.min.js?ver=8607251058f984a77c8f:7:79624
    at https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:9:2045
    at __unstableMarkListeningStores (https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:2:22094)
    at Object.__unstableMarkListeningStores (https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:2:22352)
    at p (https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:9:2010)
    at https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:9:2612
    at Qe (https://domainname.gov.uk/wp-includes/js/dist/data.min.js?ver=7c62e39de0308c73d50c:9:2824)

To fix it we have rolled back to WordPress 5.5 version.

[karan4word]

Showing this error to editors and admin

[karan4word]

Showing error only on editing any custom post type

[Mamaduka]

The error is probably coming from this line - ​https://github.com/WordPress/gutenberg/blob/3336ee9bc3490dee6d6d843a8a83229df33bfccd/packages/editor/src/store/private-selectors.js#L113.

@karan4word, it looks like your custom post types defines menu_icon property that isn't string.

Can you run following code in DevTools console, when error occurs and share the returned object?

wp.data.select( 'core' ).getPostType( wp.data.select( 'core/editor' ).getCurrentPostType() );

[karan4word]

The error also comes while creating any new post with any custom post type

That js code returns this object on dev tools console

{
    "capabilities": {
        "edit_post": "edit_post",
        "read_post": "read_post",
        "delete_post": "delete_post",
        "edit_posts": "edit_posts",
        "edit_others_posts": "edit_others_posts",
        "delete_posts": "delete_posts",
        "publish_posts": "publish_posts",
        "read_private_posts": "read_private_posts",
        "read": "read",
        "delete_private_posts": "delete_private_posts",
        "delete_published_posts": "delete_published_posts",
        "delete_others_posts": "delete_others_posts",
        "edit_private_posts": "edit_private_posts",
        "edit_published_posts": "edit_published_posts",
        "create_posts": "edit_posts"
    },
    "description": "",
    "hierarchical": false,
    "has_archive": false,
    "visibility": {
        "show_in_nav_menus": true,
        "show_ui": true
    },
    "viewable": true,
    "labels": {
        "name": "Stories",
        "singular_name": "Story",
        "add_new": "Add New",
        "add_new_item": "Add New Story",
        "edit_item": "Edit Story",
        "new_item": "New Story",
        "view_item": "View Story",
        "view_items": "View Posts",
        "search_items": "Search Stories",
        "not_found": "No Stories found",
        "not_found_in_trash": "No Stories found in Trash",
        "parent_item_colon": null,
        "all_items": "Stories",
        "archives": "Stories",
        "attributes": "Post Attributes",
        "insert_into_item": "Insert into post",
        "uploaded_to_this_item": "Uploaded to this post",
        "featured_image": "Featured image",
        "set_featured_image": "Set featured image",
        "remove_featured_image": "Remove featured image",
        "use_featured_image": "Use as featured image",
        "filter_items_list": "Filter posts list",
        "filter_by_date": "Filter by date",
        "items_list_navigation": "Posts list navigation",
        "items_list": "Posts list",
        "item_published": "Post published.",
        "item_published_privately": "Post published privately.",
        "item_reverted_to_draft": "Post reverted to draft.",
        "item_trashed": "Post binned.",
        "item_scheduled": "Post scheduled.",
        "item_updated": "Post updated.",
        "item_link": "Post Link",
        "item_link_description": "A link to a post.",
        "menu_name": "Stories",
        "name_admin_bar": "Story",
        "template_name": "Single item: Story"
    },
    "name": "Stories",
    "slug": "story",
    "icon": false,
    "supports": {
        "title": true,
        "editor": true,
        "excerpt": true,
        "custom-fields": true,
        "thumbnail": true,
        "author": true,
        "page-attributes": true,
        "autosave": true
    },
    "taxonomies": [
        "category",
        "post_tag"
    ],
    "rest_base": "story",
    "rest_namespace": "wp/v2",
    "template": [],
    "template_lock": false,
    "yoast_head": null,
    "yoast_head_json": null,
    "_links": {
        "collection": [
            {
                "href": "https://domainname.gov.uk/wp-json/wp/v2/types"
            }
        ],
        "wp:items": [
            {
                "href": "https://domainname.gov.uk/wp-json/wp/v2/story"
            }
        ],
        "curies": [
            {
                "name": "wp",
                "href": "https://api.w.org/{rel}",
                "templated": true
            }
        ]
    }
}

[karan4word]

After Setting up icon with custom post type it's allowing to edit and create posts under that custom post type but it should work fine without setting up any icon as well.

[sabernhardt]

I found two similar lines, but I do not know whether the issue is only in private-selectors.

• editor.js (​store/private-selectors) minifies to n?.icon?.startsWith("dashicons-")
• edit-site.js (​add-new-template/utils) outputs icon:e.icon?.startsWith("dashicons-")

[Mamaduka]

The block editor makes assumptions about icon values based on the REST API schema, which states that they can be string' or null`.

See ​https://github.com/WordPress/wordpress-develop/blob/c41304d73c32c968056abd2b1ffa19e83e9833a9/src/wp-includes/rest-api/endpoints/class-wp-rest-post-types-controller.php#L412-L417.

@karan4word, it looks like you're setting the menu_icon property to false, which causes the error.

I'll update the code to avoid errors when the icon doesn't match the schema type.

[Mamaduka]

Here's my proposed fix - ​https://github.com/WordPress/gutenberg/pull/64015.

Should we also harden the checks in REST API to ensure they always return the types specified in the schema?

cc @spacedmonkey, @TimothyBlynJacobs

[TimothyBlynJacobs]

Here's my proposed fix - ​https://github.com/WordPress/gutenberg/pull/64015.

It seems reasonable to me that GB expect that the REST API returns values of the type it documents. I imagine there are other parts of GB that would break if the REST API started returning data in unexpected shapes. So personally I'm not 100% sure on the need to change GB but :shrug:

Should we also harden the checks in REST API to ensure they always return the types specified in the schema?

I think we should probably fix this in register_post_type to coerce the value to string|null since it doesn't document false as a possible property value for menu_icon.

[Mamaduka]

@karan4word, do you mind commenting on the Gutenberg PR so I can give you the contribution props?

PR: ​https://github.com/WordPress/gutenberg/pull/64015

[karan4word]

@Mamaduka Done here ​https://github.com/WordPress/gutenberg/pull/64015#issuecomment-2261491127

[Mamaduka]

The bug has been fixed upstream. It will be included in the next minor release.

@sabernhardt, @TimothyBlynJacobs, should we keep this ticket open until we decide whether to fix register_post_type or the REST API?

[TimothyBlynJacobs]

Yeah I think so.