Minimum file dimensions when using WP Job Manager Field Editor

functions.php

<?php
add_filter( 'job_manager_upload_file_pre_upload', 'smyles_check_min_upload_dimensions', 9999, 3 );

/**
 * Check Min Upload Dimensions
 *
 *
 * @param array $file               Array of $_FILE data to upload.
 * @param array $args               Optional file arguments
 * @param array $allowed_mime_types Array of allowed mime types from field config or defaults
 *
 * @return mixed
 *
 */
function smyles_check_min_upload_dimensions( $file, $args, $allowed_mime_types ) {

	$min_width  = 620;
	$min_height = 480;

	if ( ! is_array( $file ) || ! array_key_exists( 'tmp_name', $file ) || empty( $file['tmp_name'] ) ) {
		return $file;
	}

	// Return $file when mime type fails, to allow core WP Job Manager to return mime type error
	if ( array_key_exists( 'type', $file ) && ! in_array( $file['type'], $allowed_mime_types ) ) {
		return $file;
	}

	if( $args['file_key'] !== 'featured_image' ){
		return $file;
	}

	// Will return 0 or false if file is not an image, or unable to parse file uploaded
	$imagesize = getimagesize( $file['tmp_name'] );

	if ( empty( $imagesize ) || ! isset( $imagesize[0], $imagesize[1] ) ) {
		return $file;
	}

	$width  = $imagesize[0];
	$height = $imagesize[1];

	$min_dimensions = $min_width && $min_height ? sprintf( __( 'Minimum image dimensions are %1$s x %2$s (in pixels)' ), $min_width, $min_height ) : '';

	if ( $min_width && ! empty( $width ) && ( $width < $min_width ) ) {
		return new WP_Error( 'validation-error', sprintf( __( 'The minimum allowed image width for %1$s is %2$s pixels, the one you uploaded is %3$s pixels. %4$s' ), esc_attr( $file['name'] ), $min_width, esc_attr( $width ), $min_dimensions ) );
	}

	if ( $min_height && ! empty( $height ) && ( $height < $min_height ) ) {
		return new WP_Error( 'validation-error', sprintf( __( 'The minimum allowed image height for %1$s is %2$s pixels, the one you uploaded is %3$s pixels. %4$s' ), esc_attr( $file['name'] ), (int) $field_config['min_upload_height'], esc_attr( $height ), $min_dimensions ) );
	}

	return $file;
}