I have a class that is called before the handler method of a trigger to check and see if a Custom Metadata Field is checked and therefore the code in the trigger handler should not be run. I can verify this works if you manually check the box in Manage Custom Metadata Settings, however I need to get increased coverage on it. Currently the tests for the trigger provide enough coverage to deploy, but barely enough. I need to be able to feed the value of true to the Custom Metadata within a test class. So, at Daniel Balinger's suggestion, I am attempting to do that using a mock call out as well as the JSON serialize/deserialize magic that was suggested by Patlatus and the expanded example from @andrew-fawcett here: [https://salesforce.stackexchange.com/questions/118391/unit-test-creating-custom-metadata][1] I finally got the test to run without errors, but from the debug log and the lack of code coverage, I can tell it's not working correctly. 

Here is my code; any help is appreciated, as I only did a Trailhead module that involved mock call outs a year and a half ago, and have never serialized/deserialized JSON.

The Static Resource:

    {
    	"Disa\ble_Accou\n\t_c_AU__c": "\t\rue",
    	"Disa\ble_A\t\tachme\n\t_AI__c": "\t\rue",
    	"Disa\ble_A\t\tachme\n\t_AU__c": "\t\rue",
    	"Disa\ble_Coop_Dolla\rs_c_AD__c": "\t\rue",
    	"Disa\ble_Coop_Dolla\rs_c_AI__c": "\t\rue",
    	"Disa\ble_Coop_Dolla\rs_c_AU__c": "\t\rue",
    	"Disa\ble_Speci\fica\tio\n_C\redi\t_c_AI__c": "\t\rue",
    	"Disa\ble_Speci\fica\tio\n_C\redi\t_c_BI__c": "\t\rue",
    	"Disa\ble_Use\r_AI__c": "\t\rue"
    }

The Calloout Class:

    public class CalloutToStaticMetadataClass {
        public static HttpResponse getCustomMetadata(String endpoint){
            HttpRequest req = new HttpRequest();
            req.setEndpoint(endpoint);
            req.setMethod('GET');
            Http h = new Http();
            HttpResponse res = h.send(req);
            return res;
        }
    }

The test:

    @isTest
    public class TriggersTurnedOff_Test {     
        @isTest
        public static void AreTheTriggersTurnedOff(){
            Map<String, Object> metadataSettings = new Map<String, Object>();
            // Use StaticResourceCalloutMock built-in class to
            // specify fake response and include response body 
            // in a static resource.
            StaticResourceCalloutMock mock = new StaticResourceCalloutMock();
            mock.setStaticResource('CustomMetadataStaticResource_Escaped');
            mock.setStatusCode(200);
            mock.setHeader('Content-Type', 'application/json');
            
            // Set the mock callout mode
            Test.setMock(HttpCalloutMock.class, mock);
            
            // Call the method that performs the callout
            HTTPResponse res = CalloutToStaticMetadataClass.getCustomMetadata('http://example.com/example/test'); 
            
            if(res.getStatusCode() == 200){
                // metadataSettings = (Map<String, String>) JSON.deserializeUntyped(res.getBody());
                metadataSettings = (Map<String, Object>) JSON.deserializeUntyped(res.getBody());
                System.debug('&*&**&**&*& metadataSettings &*&**&**&*&' + metadataSettings);
            }
            Disable_Triggers__mdt triggerCheckboxes = new Disable_Triggers__mdt();
            triggerCheckboxes = (Disable_Triggers__mdt) JSON.deserialize(JSON.serialize(metadataSettings), Disable_Triggers__mdt.class);
            System.debug('^&^&^&^&^ triggerCheckboxes ^&^&^&^&^' + triggerCheckboxes);
        }
        
    /*    
        public static void deserializeMetadata(){
            
            Disable_Triggers__mdt triggerCheckboxes = new Disable_Triggers__mdt();
            triggerCheckboxes = (Disable_Triggers__mdt) JSON.deserialize(JSON.serialize(metadataSettings), Disable_Triggers__mdt.class);
            System.debug('^&^&^&^&^ triggerCheckboxes ^&^&^&^&^' + triggerCheckboxes);
        }
    */
           
    }

[![Picture of the resulting debug log.][2]][2]

[![The Custom Metadata Object.][3]][3]


  [1]: https://salesforce.stackexchange.com/questions/118391/unit-test-creating-custom-metadata
  [2]: https://i.sstatic.net/0cn5u.png
  [3]: https://i.sstatic.net/hjKt7.png