Hi All,

Can anyone Please help to write a test class for my class?

Apex Class:

public without sharing class _CalendarCtrl extends _Ctrl {
    public List<SelectOption> categoryOptions {get; set;}
    public List<SelectOption> regionOptions {get; set;}

    public String selectedCategory {get; set;}
    public String selectedRegion {get; set;}

    public String selectedFromDate {get; set;}
    public String selectedToDate {get; set;}

    public String selectedPage {get; set;}
    public Integer selectedPageNumber {get; set;}

    public List<Calendar_Event__c> ccalendarEvents {get; set;}

    public Map<Id, List<String>> eventIdToCategories {get; set;}

    public Integer numberOfResultsPerPage {get; set;}
    public Integer numberOfPages {get; set;}

    public Map<String, Id> categoryToAttachmentIdMap {get; set;}

    public _CalendarCtrl() {
        populateCategoryOptions();
        populateRegionOptions();

        selectedCategory = ApexPages.currentPage().getParameters().get('category');
        selectedRegion = ApexPages.currentPage().getParameters().get('region');

        selectedFromDate = ApexPages.currentPage().getParameters().get('from-date');
        if(selectedFromDate == null) {
            selectedFromDate = Date.today().format();        
        }
        
        selectedToDate = ApexPages.currentPage().getParameters().get('to-date');

        selectedPage = ApexPages.currentPage().getParameters().get('page');
        
        selectedPageNumber = 1;
        if(String.isNotEmpty(selectedPage)) {
            selectedPageNumber = Integer.valueOf(selectedPage);
        }

        numberOfResultsPerPage = Integer.valueOf(Version.Calendar_Num_Results_Per_Page__c);

        populateCalendarEvents();
        populateEventIdToCategoriesMap();
        
        populateCategoryToAttachmentIdMap();
    }

    public void populateCalendarEvents() {
        List<String> whereClauseConditions = new List<String>();

        if(String.isNotEmpty(selectedRegion) && selectedRegion != 'all') {
            whereClauseConditions.add('Region__c = :selectedRegion');
        }

        if(String.isNotEmpty(selectedCategory) && selectedCategory != 'all') {
            whereClauseConditions.add('Categories__c includes (:selectedCategory)');
        }

        Date fromDate = null;
        if(String.isNotEmpty(selectedFromDate)) {
            fromDate = Date.parse(selectedFromDate);
            whereClauseConditions.add('Event_Date__c >= :fromDate');
        }

        Date toDate = null;
        if(String.isNotEmpty(selectedToDate)) {
            toDate = Date.parse(selectedToDate).addDays(1);
            whereClauseConditions.add('Event_Date__c < :toDate');
        }

        String query = 'SELECT Name, Event_Date__c, Event_End_Date__c,Event_Start_Time__c,Event_End_Time__c,Summary__c, Region__c, Categories__c FROM Calendar_Event__c';
        if(!whereClauseConditions.isEmpty()) {
            query += ' WHERE ' + String.join(whereClauseConditions, ' AND ');
        }
        
        String countQuery = 'SELECT Count() FROM Calendar_Event__c';
        if(!whereClauseConditions.isEmpty()) {
            countQuery += ' WHERE ' + String.join(whereClauseConditions, ' AND ');
        }

        query += ' ORDER BY Event_Date__c ASC LIMIT :numberOfResultsPerPage';

        Integer numResults = Database.countQuery(countQuery);
        numberOfPages = Integer.valueOf(Math.ceil(numResults / (double)numberOfResultsPerPage));

        if(String.isNotEmpty(selectedPage) && selectedPage != '1') {
            Integer offset = (Integer.valueOf(selectedPage) - 1) * numberOfResultsPerPage;
            query += ' OFFSET ' + offset;
        }

        ccalendarEvents = Database.query(query);
        

        //return [SELECT Name, Event_Date__c, Summary__c, Region__c, Categories__c FROM Calendar_Event__c WHERE Region__c = :selectedRegion AND Categories__c includes (:selectedCategory)];
    }

    public List<Integer> getPageNumberList() {
        List<Integer> pageNumberList = new List<Integer>();
        for(Integer i=1; i<=numberOfPages; i++) {
            pageNumberList.add(i);
        }

        return pageNumberList;
    }

    private void populateCategoryOptions() {
        categoryOptions = new List<SelectOption>();
        for(Schema.PicklistEntry f : Calendar_Event__c.Categories__c.getDescribe().getPicklistValues()) {
            categoryOptions.add(new SelectOption(f.getLabel(), f.getValue()));
        }
    }

    private void populateRegionOptions() {
        regionOptions = new List<SelectOption>();
        for(Schema.PicklistEntry f : Calendar_Event__c.Region__c.getDescribe().getPicklistValues()) {
            regionOptions.add(new SelectOption(f.getLabel(), f.getValue()));
        }
    }

    private void populateEventIdToCategoriesMap() {
        eventIdToCategories = new Map<Id, List<String>>();

        for(Calendar_Event__c cEvent : ccalendarEvents) {
            eventIdToCategories.put(cEvent.Id, String.valueOf(cEvent.Categories__c).split(';'));
        }
    }
    
    private void populateCategoryToAttachmentIdMap() {
        categoryToAttachmentIdMap = new Map<String, Id>();
        
        for(__Calendar_Category__c cc : Version.__Calendar_Categories__r) {
            if(cc.Category_Icon_Ref__c != null) {
                categoryToAttachmentIdMap.put(cc.name, cc.Category_Icon_Ref__r.Attachment_Id__c);
            }
        }
    }
}

my Test Class

@isTest

public without sharing class SiteCalendarCtrl_Test{
static testMethod void Testdata() {
Test.startTest();
CalendarCtrl Calendar= new CalendarCtrl();
Calendar.populateCalendarEvents();
Calendar.getPageNumberList();
Test.stopTest();
}
}
Error:

CalendarCtrl_Test.Testdata: line 5, column 1

Appreciate for your quick help!