diff --git a/src/models/ApiResponseFactory.ts b/src/models/ApiResponseFactory.ts
index d91a290..975efba 100644
--- a/src/models/ApiResponseFactory.ts
+++ b/src/models/ApiResponseFactory.ts
@@ -29,9 +29,9 @@ export class ApiResponseFactory {
    */
   private static TryToGetMessage(response: AxiosResponse): string {
     if (
-      response.status == HttpStatusCode.Unauthorized ||
-      response.status == HttpStatusCode.Forbidden ||
-      response.status == HttpStatusCode.NotFound
+      response.status === HttpStatusCode.Unauthorized ||
+      response.status === HttpStatusCode.Forbidden ||
+      response.status === HttpStatusCode.NotFound
     ) {
       return response.data?.message;
     }
diff --git a/tests/ApiResponseFactory.spec.ts b/tests/ApiResponseFactory.spec.ts
index 30e94ad..ca3b611 100644
--- a/tests/ApiResponseFactory.spec.ts
+++ b/tests/ApiResponseFactory.spec.ts
@@ -16,7 +16,7 @@ describe('ApiResponseFactory', function () {
       expect(ApiResponseFactory.getApiResponse).to.have.lengthOf(1);
     });
 
-    it('should return an ApiResponse object', function () {
+    it('should return an ApiResponse object when request is successful', function () {
       const response: AxiosResponse = {
         data: null,
         status: 200,
@@ -35,5 +35,153 @@ describe('ApiResponseFactory', function () {
       expect(apiResponse.message).to.equal('');
       expect(apiResponse.data).to.equal(null);
     });
+
+    it('should return an ApiResponse object without a message value when request is forbidden and the response does not contain a message property', function () {
+      const response: AxiosResponse = {
+        data: null,
+        status: 403,
+        statusText: 'Forbidden',
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      };
+
+      const apiResponse = ApiResponseFactory.getApiResponse(response);
+
+      expect(apiResponse).to.not.be.undefined;
+      expect(apiResponse).to.have.property('statusCode');
+      expect(apiResponse).to.have.property('message');
+      expect(apiResponse).to.have.property('data');
+      expect(apiResponse.statusCode).to.equal(403);
+      expect(apiResponse.message).to.equal(undefined);
+      expect(apiResponse.data).to.equal(null);
+    });
+
+    it('should return an ApiResponse object when request is forbidden and the response contains a message property', function () {
+      const response: AxiosResponse = {
+        data: {
+          message: 'Does not have permission to access this resource.'
+        },
+        status: 403,
+        statusText: 'Forbidden',
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      };
+
+      const apiResponse = ApiResponseFactory.getApiResponse(response);
+
+      expect(apiResponse).to.not.be.undefined;
+      expect(apiResponse).to.have.property('statusCode');
+      expect(apiResponse).to.have.property('message');
+      expect(apiResponse).to.have.property('data');
+      expect(apiResponse.statusCode).to.equal(403);
+      expect(apiResponse.message).to.equal('Does not have permission to access this resource.');
+      expect(apiResponse.data).to.equal(null);
+    });
+
+    it('should return an ApiResponse object without a message value when request is not found and the response does not contain a message property', function () {
+      const response: AxiosResponse = {
+        data: null,
+        status: 404,
+        statusText: 'Not Found',
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      };
+
+      const apiResponse = ApiResponseFactory.getApiResponse(response);
+
+      expect(apiResponse).to.not.be.undefined;
+      expect(apiResponse).to.have.property('statusCode');
+      expect(apiResponse).to.have.property('message');
+      expect(apiResponse).to.have.property('data');
+      expect(apiResponse.statusCode).to.equal(404);
+      expect(apiResponse.message).to.equal(undefined);
+      expect(apiResponse.data).to.equal(null);
+    });
+
+    it('should return an ApiResponse object with a message value when request is not found and the response contains a message property', function () {
+      const response: AxiosResponse = {
+        data: {
+          message: 'Resource not found.'
+        },
+        status: 404,
+        statusText: 'Not Found',
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      };
+
+      const apiResponse = ApiResponseFactory.getApiResponse(response);
+
+      expect(apiResponse).to.not.be.undefined;
+      expect(apiResponse).to.have.property('statusCode');
+      expect(apiResponse).to.have.property('message');
+      expect(apiResponse).to.have.property('data');
+      expect(apiResponse.statusCode).to.equal(404);
+      expect(apiResponse.message).to.equal('Resource not found.');
+      expect(apiResponse.data).to.equal(null);
+    });
+
+    it('should return an ApiResponse object without a message value when request is unauthorized and the response does not contain a message property', function () {
+      const response: AxiosResponse = {
+        data: null,
+        status: 401,
+        statusText: 'Unauthorized',
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      };
+
+      const apiResponse = ApiResponseFactory.getApiResponse(response);
+
+      expect(apiResponse).to.not.be.undefined;
+      expect(apiResponse).to.have.property('statusCode');
+      expect(apiResponse).to.have.property('message');
+      expect(apiResponse).to.have.property('data');
+      expect(apiResponse.statusCode).to.equal(401);
+      expect(apiResponse.message).to.equal(undefined);
+      expect(apiResponse.data).to.equal(null);
+    });
+
+    it('should return an ApiResponse object with a message when request is unauthorized and the response contains a message property', function () {
+      const response: AxiosResponse = {
+        data: {
+          message: 'Unauthorized.'
+        },
+        status: 401,
+        statusText: 'Unauthorized',
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      };
+
+      const apiResponse = ApiResponseFactory.getApiResponse(response);
+
+      expect(apiResponse).to.not.be.undefined;
+      expect(apiResponse).to.have.property('statusCode');
+      expect(apiResponse).to.have.property('message');
+      expect(apiResponse).to.have.property('data');
+      expect(apiResponse.statusCode).to.equal(401);
+      expect(apiResponse.message).to.equal('Unauthorized.');
+      expect(apiResponse.data).to.equal(null);
+    });
+
+    it('should return an ApiResponse object with a message when request is a bad request', function () {
+      const response: AxiosResponse = {
+        data: {
+          field: 'Invalid input.'
+        },
+        status: 400,
+        statusText: 'Bad Request',
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      };
+
+      const apiResponse = ApiResponseFactory.getApiResponse(response);
+
+      expect(apiResponse).to.not.be.undefined;
+      expect(apiResponse).to.have.property('statusCode');
+      expect(apiResponse).to.have.property('message');
+      expect(apiResponse).to.have.property('data');
+      expect(apiResponse.statusCode).to.equal(400);
+      expect(apiResponse.message).to.equal('{"field":"Invalid input."}');
+      expect(apiResponse.data).to.equal(null);
+    });
   });
 });
\ No newline at end of file
diff --git a/tests/App.spec.ts b/tests/App.spec.ts
index a333b92..e4050bd 100644
--- a/tests/App.spec.ts
+++ b/tests/App.spec.ts
@@ -17,4 +17,15 @@ describe('App', function () {
   it('should create a new instance of the App class', function () {
     expect(() => new App('href', 1, 'name')).to.not.throw();
   });
+
+  it('should create a new instance of the App class with the correct properties and values', function () {
+    const app = new App('href', 1, 'name');
+
+    expect(app).to.have.property('href');
+    expect(app).to.have.property('id');
+    expect(app).to.have.property('name');
+    expect(app.href).to.equal('href');
+    expect(app.id).to.equal(1);
+    expect(app.name).to.equal('name');
+  });
 });
\ No newline at end of file
diff --git a/tests/OnspringClient.spec.ts b/tests/OnspringClient.spec.ts
index 705e470..7e74af2 100644
--- a/tests/OnspringClient.spec.ts
+++ b/tests/OnspringClient.spec.ts
@@ -1,5 +1,6 @@
 import { OnspringClient } from '../src/OnspringClient';
 import { ApiResponse } from '../src/models/ApiResponse';
+import axios, { AxiosResponse, InternalAxiosRequestConfig } from 'axios';
 import { expect } from 'chai';
 import * as sinon from 'sinon';
 
@@ -85,7 +86,7 @@ describe('OnspringClient', function () {
     expect(() => new OnspringClient(baseUrl, apiKey)).to.not.throw();
   });
 
-  it('should have a client property', function () {
+  it('should create a new instance of an onspring client with proper properties', function () {
     expect(new OnspringClient(baseUrl, apiKey)).to.have.property('_client');
   });
 
@@ -114,14 +115,50 @@ describe('OnspringClient', function () {
 
     it('should return a promise that resolves to true when able to connect to the Onspring API', async function () {
       const client = new OnspringClient(baseUrl, apiKey);
-      sinon.stub(client, 'get' as any).returns(Promise.resolve(new ApiResponse(200, 'OK', null)));
+
+      const mockClient = axios.create({
+        baseURL: baseUrl,
+        headers: {
+          'x-apikey': apiKey,
+          'x-api-version': '2',
+        },
+      });
+      
+      sinon.stub(mockClient, 'get').returns(Promise.resolve({
+        status: 200,
+        statusText: 'OK',
+        data: null,
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      } as AxiosResponse));
+
+      sinon.stub(client, '_client' as any).value(mockClient);
+
       const result = await client.canConnect();
       expect(result).to.be.true;
     });
 
     it('should return a promise that resolves to false when unable to connect to the Onspring API', async function () {
       const client = new OnspringClient(baseUrl, apiKey);
-      sinon.stub(client, 'get' as any).returns(Promise.resolve(new ApiResponse(500, 'Internal Server Error', null)));
+      // sinon.stub(client, 'get' as any).returns(Promise.resolve(new ApiResponse(500, 'Internal Server Error', null)));
+      const mockClient = axios.create({
+        baseURL: baseUrl,
+        headers: {
+          'x-apikey': apiKey,
+          'x-api-version': '2',
+        },
+      });
+
+      sinon.stub(mockClient, 'get').returns(Promise.reject({
+        status: 500,
+        statusText: 'Internal Server Error',
+        data: null,
+        headers: {},
+        config: {} as InternalAxiosRequestConfig,
+      } as AxiosResponse));
+
+      sinon.stub(client, '_client' as any).value(mockClient);
+      
       const result = await client.canConnect();
       expect(result).to.be.false;
     });
diff --git a/tests/PagingRequest.spec.ts b/tests/PagingRequest.spec.ts
index 23fe659..decb9dc 100644
--- a/tests/PagingRequest.spec.ts
+++ b/tests/PagingRequest.spec.ts
@@ -29,4 +29,13 @@ describe('PagingRequest', function () {
   it('should create a new instance of the PagingRequest class when the pageNumber is greater than 0 and the pageSize is between 1 and 1000', function () {
     expect(() => new PagingRequest(1, 1)).to.not.throw();
   });
+
+  it('should create a new instance of the PagingRequest class with the correct properties and values', function () {
+    const pagingRequest = new PagingRequest(1, 1);
+
+    expect(pagingRequest).to.have.property('pageNumber');
+    expect(pagingRequest).to.have.property('pageSize');
+    expect(pagingRequest.pageNumber).to.equal(1);
+    expect(pagingRequest.pageSize).to.equal(1);
+  });
 });
\ No newline at end of file