Example: Custom Trigger for Attachment

Apex Trigger

trigger CustomAttachmentTrigger on Attachment (after insert) {
    List<Attachment> caseAttachments = new List<Attachment>();

    // if Detection is turned on for Attachment
    if (pcify.Manager.getManager('Attachment').pcify__isActive__c) {
        // collect Case Attachments
        for (Attachment att : Trigger.new) {
            if (att.ParentId.getSobjectType() == Case.getSObjectType()) {
                caseAttachments.add(att);
            }
        }
        // process only case Attachments with PCIFY
        if (!caseAttachments.isEmpty()) {
            CustomAttachmentTriggerHandler.scanFiles(caseAttachments);
        }
    }
}

Apex Handler Class

public with sharing class CustomAttachmentTriggerHandler {

    public static void scanFiles(List<SObject> files) {
        List<String> fileIds = new List<String>();
        pcify__Manager__mdt manager = pcify.Manager.getManager('Attachment');

        for (SObject file : files) {
            fileIds.add(file.Id);
        }
        pcifyfiles.FileDetector batchJob = new pcifyfiles.FileDetector();
        batchJob.objectName = 'Attachment';
        batchJob.fieldNames = manager.pcify__MaskFields__c.deleteWhitespace().split(',');
        batchJob.fileIds = fileIds;
        batchJob.queryLimit = Integer.valueOf(manager.pcify__BatchQueryLimit__c);
        batchJob.batchSize = Integer.valueOf(manager.pcify__BatchSize__c);
        batchJob.action = manager.pcify__AuditAction__c;
        batchJob.loadQuery();
        database.executebatch(batchJob, batchJob.batchSize);
    }
}

Test Class

@isTest
public with sharing class CustomAttachmentTriggerHandlerTEST {

    @isTest
    static void testCustomAttachmentTrigger() {

        Case c = new Case();
        c.Origin = 'Email';
        c.Description = 'testing';
        insert c;

        Attachment file = new Attachment();
        file.ParentId = c.Id;
        file.Name = 'test';
        file.ContentType = 'application/msword';
        String body = '{\"ParsedResults\":[{\"TextOverlay\":{\"Lines\":[],\"HasOverlay\":false,\"Message\":\"Text overlay is not provided as it is not requested\"},'+
        '\"TextOrientation\":\"0\",\"FileParseExitCode\":1,\"ParsedText\":\"Demo Cards 4355230837762992 4355-2308-3776-2992\",'+
        '\"ErrorMessage\":\"\",\"ErrorDetails\":\"\"}],\"OCRExitCode\":1,\"IsErroredOnProcessing\":false,\"ProcessingTimeInMilliseconds\":\"669\",'+
        '\"SearchablePDFURL\":\"Searchable PDF not generated as it was not requested.\"}';
        Blob mockbody = Blob.valueof(body);
        file.Body = mockbody;

        Test.startTest();
        insert file;
        Test.stopTest();

        List<Attachment> attachments = [SELECT Id FROM Attachment];
        System.assertEquals(attachments.size(), 1);
        List<pcify__Log__c> logs = [SELECT Id, pcify__Object__c, pcify__Category__c, pcify__RecordId__c FROM pcify__Log__c];
        System.assertEquals(2, logs.size());
        System.assertEquals(logs[0].pcify__Category__c, 'Record Reported');
        System.assertEquals(logs[0].pcify__Object__c, 'Attachment');
        System.assertEquals(logs[0].pcify__RecordId__c, attachments[0].Id);
    }
}