Specifying MySQL Index Size in Laravel

When writing migrations, if you've come across an error specified key was too long; max key length is 3072 bytes, this might help you as it did when I faced this issue on my job board.

Laravel's Blueprint $table accepts a raw statement, so you can define it this way

Schema::table('table_name', function (Blueprint $table) {
    $table->index([DB::raw('field_name(50)')], 'index_name');
});

index_name is optional as Laravel neatly prefixes table name to field name, so it becomes table_name_field_name

As to why this error occurs and finding the ideal index size, this is a great answer on Stackoverflow