Fix TypeError: Cannot read properties of undefined (reading 'localeCompare')

[EarthmanWeb]

Summary

Fixes an Uncaught TypeError: Cannot read properties of undefined (reading 'localeCompare') thrown on every admin page load from scf-admin.min.js.

Problem

Both admin-commands.js and custom-post-type-commands.js read window.acf.data.wp_version and immediately call .localeCompare() on it to determine if the WordPress version is 6.9+. However, wp_version is only added to acf.data conditionally in includes/assets.php (line 622), inside a block that checks for Gutenberg/block editor context. On classic editor pages and other admin screens where that condition isn't met, wp_version is undefined, causing the TypeError.

Error:

Uncaught TypeError: Cannot read properties of undefined (reading 'localeCompare')
    at h (scf-admin.min.js?ver=6.8.0:1:6456)

This error fires on every admin page load via requestIdleCallback.

Fix

Added a fallback || '0' when reading window.acf.data.wp_version in both files:

// Before (crashes when wp_version is undefined)
const wpVersion = window.acf.data.wp_version;

// After (safely falls back to '0', treating unknown versions as pre-6.9)
const wpVersion = window.acf.data.wp_version || '0';

When wp_version is undefined, the fallback '0' ensures localeCompare('6.9') returns < 0, so all commands are registered (pre-6.9 behavior). This is the safe default — registering extra commands is harmless, while crashing is not.

Files Changed

• assets/src/js/commands/admin-commands.js — Added || '0' fallback (line 216)
• assets/src/js/commands/custom-post-type-commands.js — Added || '0' fallback (line 41)
• tests/js/commands/admin-commands.test.js — Added test case for undefined wp_version
• tests/js/commands/custom-post-type-commands.test.js — Added test case for undefined wp_version

Test Plan

• Verified fix resolves the error on a production WordPress 6.9.1 site
• Confirmed all existing commands still register correctly
• npm run test:unit passes with new undefined version test cases
• Verify on WP 6.9+ that view commands are correctly skipped when wp_version is available

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props earthman100, bernhard-reiter.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[ockham]

Good spot, thank you!

As for the fix, I think it'd be better if we bailed early if window.acf.data.wp_version isn't available (rather than defaulting the WP version number to 0).

Turns out that we already have checks that look like they're supposed to cover cases like these:

secure-custom-fields/assets/src/js/commands/admin-commands.js

Lines 34 to 36 in 8b53724

	if ( ! dispatch( 'core/commands' ) || ! window.acf?.data ) {
	return;
	}

and

secure-custom-fields/assets/src/js/commands/custom-post-type-commands.js

Lines 28 to 34 in 8b53724

	// Only proceed when WordPress commands API and there are custom post types accessible
	if (
	! dispatch( 'core/commands' ) ||
	! window.acf?.data?.customPostTypes?.length
	) {
	return;
	}

They just don't seem to quite cover the case where wp_version isn't present 🤔
Maybe you can tweak those conditionals?

[ockham]

Looking a bit more into this had me discover a related/underlying issue: When the command palette is invoked (Cmd+K) from a non-editor wp-admin screen, SCF options aren't added there. (This is due to the conditionals I mentioned.)

Editor	Other wp-admin