adding mockclient to access k8 api and return mock response

Signed-off-by: Philip-21 <[email protected]>

utils/kubernetes/describe/describe_test.go

@@ -0,0 +1,196 @@
+package describe
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"testing"
+
+)
+
+// A MockClient meant to interact with the Kubernetes Api
+type MockClient struct {
+	Response      []byte //stores the response body that should be returned when the MockClient makes a request.
+	RequestUrl    string // stores the URL that the Mock client should expect when the HTTP request is performed
+	RequestMethod string // stores the HTTP request method made by the mock client
+	RequestBody   []byte // stores the request body that the fake client should expect to receive when the HTTP request is made
+	DescribeError error  //handle errors for Describe()
+
+}
+
+// the main role of the Prepend Reactor is to return httpErrors for Describerfunc
+// PrependReactor adds a reactor function that gets called before every mock request is sent.
+// The reactor function sets the HTTP status code to 404 if the Describe() function is called.
+func (m *MockClient) PrependReactor(method string, Name string, reactorFunc func(*http.Request) (*http.Response, error)) {
+	originalDo := m.Do
+
+	_ = func(req http.Request) (*http.Response, error) {
+		//call the reactor funtion for every reqeust
+		resp, err := reactorFunc(&req)
+		if err != nil || resp != nil {
+			// If the reactor function returns a response or error, return it immediately
+			return resp, err
+		}
+		// Otherwise, call the original Do() method
+		return originalDo(req)
+	}
+}
+
+// Do executes request and returns a response
+func (m *MockClient) Do(req http.Request) (*http.Response, error) {
+	m.RequestUrl = req.URL.String()
+	m.RequestMethod = req.Method
+	m.RequestBody, _ = ioutil.ReadAll(req.Body)
+
+	if m.DescribeError != nil && strings.Contains(m.RequestUrl, "describe") {
+		return &http.Response{
+			StatusCode: 404,
+			Body:       io.NopCloser(bytes.NewReader(m.Response)),
+		}, m.DescribeError
+	}
+	return &http.Response{
+		StatusCode: 404,
+		Body:       io.NopCloser(bytes.NewReader(m.Response)),
+	}, m.DescribeError
+
+}
+
+func (m *MockClient) Get(url string) (*http.Response, error) {
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	//calls the Do() to execute request and handle response
+	return m.Do(*req)
+
+}
+
+func (m *MockClient) Post(url string) (*http.Response, error) {
+	req, err := http.NewRequest(http.MethodPost, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	//calls the Do() to execute request and handle response
+	return m.Do(*req)
+}
+
+func (m *MockClient) Put(url string) (*http.Response, error) {
+	req, err := http.NewRequest(http.MethodPut, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	//calls the Do() to execute request and handle response
+	return m.Do(*req)
+}
+
+func (m *MockClient) Delete(url string) (*http.Response, error) {
+	req, err := http.NewRequest(http.MethodDelete, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	//calls the Do() to execute request and handle response
+	return m.Do(*req)
+}
+
+func (m *MockClient) Patch(url string) (*http.Response, error) {
+	req, err := http.NewRequest(http.MethodPatch, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return m.Do(*req)
+
+}
+
+/*
+The MockDescriber is used in the implementation of the Describe function to create a mock output that is returned when the
+function is called with specific options
+it takes in a Client object and a DescriberOptions object, and returns a string and an error
+*/
+type MockDescriber struct {
+	DescribeFunc func(MockClient, DescriberOptions) (string, error)
+}
+
+// Describe method of the MockDescriber simply calls DescribeFunc and returns the result.
+func (m *MockDescriber) Describe(client MockClient, options DescriberOptions) (string, error) {
+	return m.DescribeFunc(client, options)
+}
+
+func TestDescribe(t *testing.T) {
+	//meshkitkube.Client  provides the ability to interact with the Kubernetes API server
+
+	//set up mock client client to return expected responses
+	mockClient := MockClient{}
+
+	//create test cases
+	testCases := []struct {
+		Name           string
+		Options        DescriberOptions
+		DescribeFunc   func(MockClient, DescriberOptions) (string, error)
+		ExpectedOutput string
+		ExpectedError  error
+	}{
+		{
+			Name: "describe pod",
+			Options: DescriberOptions{
+				Name:      "test-pod",
+				Namespace: "test-namespace",
+				Type:      Pod,
+			},
+			/*
+				DescribeFunc field is a function that takes in a Client
+				object and a DescriberOptions object, and returns a string and an error
+			*/
+			DescribeFunc: func(client MockClient, options DescriberOptions) (string, error) {
+				return "Name: test-pod\nNamespace: test-namespace\n", nil
+			},
+			ExpectedOutput: "Name: test-pod\nNamespace: test-namespace\n",
+			ExpectedError:  nil,
+		},
+		{
+			Name: "describe deployment",
+			Options: DescriberOptions{
+				Name:      "test-deployment",
+				Namespace: "test-namespace",
+				Type:      Deployment,
+			},
+			DescribeFunc: func(client MockClient, options DescriberOptions) (string, error) {
+				return "Name: test-deployment\nNamespace: test-namespace\n", nil
+			},
+			ExpectedOutput: "Name: test-deployment\nNamespace: test-namespace\n",
+			ExpectedError:  nil,
+		},
+	}
+	// run test cases
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			// create a mockDescriber
+			mockDescriber := &MockDescriber{
+				DescribeFunc: tc.DescribeFunc,
+			}
+
+			// add a reactor to the mock client to return an error if the DescribeFunc is called
+			mockClient.PrependReactor("GET", "test-pod", func(req *http.Request) (*http.Response, error) {
+				return nil, fmt.Errorf("error for testpods")
+			})
+
+			mockClient.PrependReactor("GET", "test-deployment", func(*http.Request) (*http.Response, error) {
+				return nil, fmt.Errorf("error for deployment")
+			})
+
+			// call the Describe method
+			output, err := mockDescriber.Describe(mockClient, tc.Options)
+
+			// check if the output and error match the expected values
+			if output != tc.ExpectedOutput {
+				t.Errorf("Test case %s failed. Expected: %s, but got: %s", tc.Name, tc.ExpectedOutput, output)
+			}
+			if err != tc.ExpectedError {
+				t.Errorf("Test case %s failed. Expected error: %v, but got: %v", tc.Name, tc.ExpectedError, err)
+			}
+		})
+	}
+
+}