//go:build unit
// +build unit

package http

import (
	"bytes"
	"crypto/tls"
	"crypto/x509"
	"encoding/base64"
	"encoding/xml"
	"errors"
	"fmt"
	"io"
	"io/ioutil"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/jarcoal/httpmock"
	"github.com/sirupsen/logrus"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
	"github.com/stretchr/testify/require"

	"github.com/SAP/jenkins-library/pkg/log"
)

func TestSend(t *testing.T) {
	testURL := "https://example.org"

	request, err := http.NewRequest(http.MethodGet, testURL, nil)
	require.NoError(t, err)

	t.Run("success", func(t *testing.T) {
		// given
		httpmock.Activate()
		defer httpmock.DeactivateAndReset()
		httpmock.RegisterResponder(http.MethodGet, testURL, httpmock.NewStringResponder(200, `OK`))
		client := Client{}
		client.SetOptions(ClientOptions{MaxRetries: -1, UseDefaultTransport: true})
		// when
		response, err := client.Send(request)
		// then
		assert.NoError(t, err)
		assert.NotNil(t, response)
	})
	t.Run("failure", func(t *testing.T) {
		// given
		httpmock.Activate()
		defer httpmock.DeactivateAndReset()
		httpmock.RegisterResponder(http.MethodGet, testURL, httpmock.NewErrorResponder(errors.New("failure")))
		client := Client{}
		client.SetOptions(ClientOptions{MaxRetries: -1, UseDefaultTransport: true})
		// when
		response, err := client.Send(request)
		// then
		assert.Error(t, err)
		assert.Nil(t, response)
	})
	t.Run("failure when calling via proxy", func(t *testing.T) {
		// given
		httpmock.Activate()
		defer httpmock.DeactivateAndReset()
		httpmock.RegisterResponder(http.MethodGet, testURL, httpmock.NewStringResponder(200, `OK`))

		client := Client{}
		transportProxy, _ := url.Parse("https://proxy.dummy.sap.com")
		client.SetOptions(ClientOptions{MaxRetries: -1, TransportProxy: transportProxy})

		// when
		response, err := client.Send(request)

		// then
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "lookup proxy.dummy.sap.com: no such host")
		assert.Nil(t, response)
	})
}

func TestDefaultTransport(t *testing.T) {
	const testURL string = "https://localhost/api"

	t.Run("with default transport", func(t *testing.T) {
		httpmock.Activate()
		defer httpmock.DeactivateAndReset()
		httpmock.RegisterResponder(http.MethodGet, testURL, httpmock.NewStringResponder(200, `OK`))

		client := Client{}
		client.SetOptions(ClientOptions{MaxRetries: -1, UseDefaultTransport: true})
		// test
		response, err := client.SendRequest("GET", testURL, nil, nil, nil)
		// assert
		assert.NoError(t, err)
		// assert.NotEmpty(t, count)
		assert.Equal(t, 1, httpmock.GetTotalCallCount(), "unexpected number of requests")
		content, err := ioutil.ReadAll(response.Body)
		defer response.Body.Close()
		require.NoError(t, err, "unexpected error while reading response body")
		assert.Equal(t, "OK", string(content), "unexpected response content")
	})
	t.Run("with custom transport", func(t *testing.T) {
		httpmock.Activate()
		defer httpmock.DeactivateAndReset()
		httpmock.RegisterResponder(http.MethodGet, testURL, httpmock.NewStringResponder(200, `OK`))

		client := Client{}
		// test
		_, err := client.SendRequest("GET", testURL, nil, nil, nil)
		// assert
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "connection")
		assert.Contains(t, err.Error(), "refused")
		assert.Equal(t, 0, httpmock.GetTotalCallCount(), "unexpected number of requests")
	})
}

func TestSendRequest(t *testing.T) {
	var passedHeaders = map[string][]string{}
	passedCookies := []*http.Cookie{}
	var passedUsername string
	var passedPassword string

	// Start a local HTTP server
	server := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
		passedHeaders = map[string][]string{}
		if req.Header != nil {
			for name, headers := range req.Header {
				passedHeaders[name] = headers
			}
		}
		passedCookies = req.Cookies()
		passedUsername, passedPassword, _ = req.BasicAuth()

		rw.Write([]byte("OK"))
	}))
	// Close the server when test finishes
	defer server.Close()

	oldLogLevel := logrus.GetLevel()
	defer logrus.SetLevel(oldLogLevel)
	logrus.SetLevel(logrus.DebugLevel)

	tt := []struct {
		client   Client
		method   string
		body     io.Reader
		header   http.Header
		cookies  []*http.Cookie
		expected string
	}{
		{client: Client{logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http")}, method: "GET", expected: "OK"},
		{client: Client{logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http")}, method: "GET", header: map[string][]string{"Testheader": {"Test1", "Test2"}}, expected: "OK"},
		{client: Client{logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http")}, cookies: []*http.Cookie{{Name: "TestCookie1", Value: "TestValue1"}, {Name: "TestCookie2", Value: "TestValue2"}}, method: "GET", expected: "OK"},
		{client: Client{logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http"), username: "TestUser", password: "TestPwd"}, method: "GET", expected: "OK"},
		{client: Client{logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http"), token: "api-token-string"}, method: "GET", expected: "OK"},
	}

	for key, test := range tt {
		t.Run(fmt.Sprintf("Row %v", key+1), func(t *testing.T) {
			oldLogOutput := test.client.logger.Logger.Out
			defer func() { test.client.logger.Logger.Out = oldLogOutput }()
			logBuffer := new(bytes.Buffer)
			test.client.logger.Logger.Out = logBuffer

			response, err := test.client.SendRequest("GET", server.URL, test.body, test.header, test.cookies)
			assert.NoError(t, err, "Error occurred but none expected")
			content, err := ioutil.ReadAll(response.Body)
			assert.Equal(t, test.expected, string(content), "Returned content incorrect")
			response.Body.Close()

			for k, h := range test.header {
				assert.Containsf(t, passedHeaders, k, "Header %v not contained", k)
				assert.Equalf(t, h, passedHeaders[k], "Header %v contains different value")
			}

			if len(test.cookies) > 0 {
				assert.Equal(t, test.cookies, passedCookies, "Passed cookies not correct")
			}

			if len(test.client.username) > 0 || len(test.client.password) > 0 {
				if len(test.client.username) == 0 || len(test.client.password) == 0 {
					//"User and password must both be provided"
					t.Fail()
				}
				assert.Equal(t, test.client.username, passedUsername)
				assert.Equal(t, test.client.password, passedPassword)

				log := fmt.Sprintf("%s", logBuffer)
				credentialsEncoded := base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", test.client.username, test.client.password)))
				assert.NotContains(t, log, fmt.Sprintf("Authorization:[Basic %s]", credentialsEncoded))
				assert.Contains(t, log, "Authorization:[<set>]")
			}

			// Token authentication
			if len(test.client.token) > 0 {
				assert.Equal(t, test.client.token, "api-token-string")
				log := fmt.Sprintf("%s", logBuffer)
				assert.Contains(t, log, fmt.Sprintf("Using Token Authentication ****"))
				assert.Contains(t, log, "Authorization:[<set>]")
			}
		})
	}
}

func TestSetOptions(t *testing.T) {
	c := Client{}
	transportProxy, _ := url.Parse("https://proxy.dummy.sap.com")
	opts := ClientOptions{MaxRetries: -1, TransportTimeout: 10, TransportProxy: transportProxy, MaxRequestDuration: 5, Username: "TestUser", Password: "TestPassword", Token: "TestToken", Logger: log.Entry().WithField("package", "github.com/SAP/jenkins-library/pkg/http")}
	c.SetOptions(opts)

	assert.Equal(t, opts.TransportTimeout, c.transportTimeout)
	assert.Equal(t, opts.TransportProxy, c.transportProxy)
	assert.Equal(t, opts.TransportSkipVerification, c.transportSkipVerification)
	assert.Equal(t, opts.MaxRequestDuration, c.maxRequestDuration)
	assert.Equal(t, opts.Username, c.username)
	assert.Equal(t, opts.Password, c.password)
	assert.Equal(t, opts.Token, c.token)
}

func TestApplyDefaults(t *testing.T) {
	tt := []struct {
		client   Client
		expected Client
	}{
		{client: Client{}, expected: Client{transportTimeout: 3 * time.Minute, maxRequestDuration: 0, logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http")}},
		{client: Client{transportTimeout: 10, maxRequestDuration: 5}, expected: Client{transportTimeout: 10, maxRequestDuration: 5, logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http")}},
	}

	for k, v := range tt {
		v.client.applyDefaults()
		assert.Equal(t, v.expected, v.client, fmt.Sprintf("Run %v failed", k))
	}
}

func TestUploadRequest(t *testing.T) {
	var passedHeaders = map[string][]string{}
	passedCookies := []*http.Cookie{}
	var passedUsername string
	var passedPassword string
	var multipartFile multipart.File
	var multipartHeader *multipart.FileHeader
	var passedFileContents []byte
	// Start a local HTTP server
	server := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
		passedHeaders = map[string][]string{}
		if req.Header != nil {
			for name, headers := range req.Header {
				passedHeaders[name] = headers
			}
		}
		passedCookies = req.Cookies()
		passedUsername, passedPassword, _ = req.BasicAuth()
		err := req.ParseMultipartForm(4096)
		if err != nil {
			t.FailNow()
		}
		multipartFile, multipartHeader, err = req.FormFile("Field1")
		if err != nil {
			t.FailNow()
		}
		defer req.Body.Close()
		passedFileContents, err = ioutil.ReadAll(multipartFile)
		if err != nil {
			t.FailNow()
		}

		rw.Write([]byte("OK"))
	}))
	// Close the server when test finishes
	defer server.Close()

	testFile, err := ioutil.TempFile("", "testFileUpload")
	if err != nil {
		t.FailNow()
	}
	defer os.RemoveAll(testFile.Name()) // clean up

	fileContents, err := ioutil.ReadFile(testFile.Name())
	if err != nil {
		t.FailNow()
	}

	tt := []struct {
		clientOptions ClientOptions
		method        string
		body          io.Reader
		header        http.Header
		cookies       []*http.Cookie
		expected      string
	}{
		{clientOptions: ClientOptions{MaxRetries: -1}, method: "PUT", expected: "OK"},
		{clientOptions: ClientOptions{MaxRetries: -1}, method: "POST", expected: "OK"},
		{clientOptions: ClientOptions{MaxRetries: -1}, method: "POST", header: map[string][]string{"Testheader": {"Test1", "Test2"}}, expected: "OK"},
		{clientOptions: ClientOptions{MaxRetries: -1}, cookies: []*http.Cookie{{Name: "TestCookie1", Value: "TestValue1"}, {Name: "TestCookie2", Value: "TestValue2"}}, method: "POST", expected: "OK"},
		{clientOptions: ClientOptions{MaxRetries: -1, Username: "TestUser", Password: "TestPwd"}, method: "POST", expected: "OK"},
		{clientOptions: ClientOptions{MaxRetries: -1, Username: "UserOnly", Password: ""}, method: "POST", expected: "OK"},
	}

	client := Client{logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http")}
	for key, test := range tt {
		t.Run(fmt.Sprintf("UploadFile Row %v", key+1), func(t *testing.T) {
			client.SetOptions(test.clientOptions)
			response, err := client.UploadFile(server.URL, testFile.Name(), "Field1", test.header, test.cookies, "form")
			assert.NoError(t, err, "Error occurred but none expected")
			content, err := ioutil.ReadAll(response.Body)
			assert.NoError(t, err, "Error occurred but none expected")
			assert.Equal(t, test.expected, string(content), "Returned content incorrect")
			response.Body.Close()

			assert.Equal(t, filepath.Base(testFile.Name()), multipartHeader.Filename, "Uploaded file incorrect")
			assert.Equal(t, fileContents, passedFileContents, "Uploaded file incorrect")

			for k, h := range test.header {
				assert.Containsf(t, passedHeaders, k, "Header %v not contained", k)
				assert.Equalf(t, h, passedHeaders[k], "Header %v contains different value")
			}

			if len(test.cookies) > 0 {
				assert.Equal(t, test.cookies, passedCookies, "Passed cookies not correct")
			}

			if len(client.username) > 0 {
				assert.Equal(t, client.username, passedUsername)
			}

			if len(client.password) > 0 {
				assert.Equal(t, client.password, passedPassword)
			}
		})
		t.Run(fmt.Sprintf("UploadRequest Row %v", key+1), func(t *testing.T) {
			client.SetOptions(test.clientOptions)
			response, err := client.UploadRequest(test.method, server.URL, testFile.Name(), "Field1", test.header, test.cookies, "form")
			assert.NoError(t, err, "Error occurred but none expected")
			content, err := ioutil.ReadAll(response.Body)
			assert.NoError(t, err, "Error occurred but none expected")
			assert.Equal(t, test.expected, string(content), "Returned content incorrect")
			response.Body.Close()

			assert.Equal(t, filepath.Base(testFile.Name()), multipartHeader.Filename, "Uploaded file incorrect")
			assert.Equal(t, fileContents, passedFileContents, "Uploaded file incorrect")

			for k, h := range test.header {
				assert.Containsf(t, passedHeaders, k, "Header %v not contained", k)
				assert.Equalf(t, h, passedHeaders[k], "Header %v contains different value")
			}

			if len(test.cookies) > 0 {
				assert.Equal(t, test.cookies, passedCookies, "Passed cookies not correct")
			}

			if len(client.username) > 0 {
				assert.Equal(t, client.username, passedUsername)
			}

			if len(client.password) > 0 {
				assert.Equal(t, client.password, passedPassword)
			}
		})
	}
}

func TestUploadRequestWrongMethod(t *testing.T) {
	client := Client{logger: log.Entry().WithField("package", "SAP/jenkins-library/pkg/http")}
	_, err := client.UploadRequest("GET", "dummy", "testFile", "Field1", nil, nil, "form")
	assert.Error(t, err, "No error occurred but was expected")
}

func TestTransportTimout(t *testing.T) {
	t.Run("timeout works on transport level", func(t *testing.T) {
		// init
		svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Sleep for longer than the configured timeout
			time.Sleep(2 * time.Second)
		}))
		defer svr.Close()

		client := Client{transportTimeout: 1 * time.Second}
		buffer := bytes.Buffer{}

		// test
		_, err := client.SendRequest(http.MethodGet, svr.URL, &buffer, nil, nil)
		// assert
		if assert.Error(t, err, "expected request to fail") {
			assert.Contains(t, err.Error(), "timeout awaiting response headers")
		}
	})
	t.Run("timeout is not hit on transport level", func(t *testing.T) {
		// init
		svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// Sleep for less than the configured timeout
			time.Sleep(1 * time.Second)
		}))
		defer svr.Close()

		client := Client{transportTimeout: 2 * time.Second}
		buffer := bytes.Buffer{}
		// test
		_, err := client.SendRequest(http.MethodGet, svr.URL, &buffer, nil, nil)
		// assert
		assert.NoError(t, err)
	})
}

func TestTransportSkipVerification(t *testing.T) {
	testCases := []struct {
		client        Client
		expectedError string
	}{
		{client: Client{}, expectedError: "certificate signed by unknown authority"},
		{client: Client{transportSkipVerification: false}, expectedError: "certificate signed by unknown authority"},
		{client: Client{transportSkipVerification: true}},
	}

	for _, testCase := range testCases {
		// init
		svr := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
		defer svr.Close()
		// test
		_, err := testCase.client.SendRequest(http.MethodGet, svr.URL, &bytes.Buffer{}, nil, nil)
		// assert
		if len(testCase.expectedError) > 0 {
			assert.Error(t, err, "certificate signed by unknown authority")
		} else {
			assert.NoError(t, err)
		}
	}
}

func TestTransportWithCertifacteAdded(t *testing.T) {
	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		io.WriteString(w, "Hello")
	}))
	defer server.Close()

	certs := x509.NewCertPool()
	for _, c := range server.TLS.Certificates {
		roots, err := x509.ParseCertificates(c.Certificate[len(c.Certificate)-1])
		if err != nil {
			println("error parsing server's root cert: %v", err)
		}
		for _, root := range roots {
			certs.AddCert(root)
		}
	}
	client := http.Client{Transport: &http.Transport{TLSClientConfig: &tls.Config{RootCAs: certs, InsecureSkipVerify: false}}}
	_, err := client.Get(server.URL)
	// assert
	assert.NoError(t, err)
}

func TestMaxRetries(t *testing.T) {
	testCases := []struct {
		client       Client
		countedCalls int
		method       string
		responseCode int
		errorText    string
		timeout      bool
	}{
		{client: Client{maxRetries: 1, useDefaultTransport: true, transportSkipVerification: true, transportTimeout: 1 * time.Microsecond}, responseCode: 666, timeout: true, countedCalls: 2, method: http.MethodPost, errorText: "timeout awaiting response headers"},
		{client: Client{maxRetries: 0}, countedCalls: 1, method: http.MethodGet, responseCode: 500, errorText: "Internal Server Error"},
		{client: Client{maxRetries: 2}, countedCalls: 3, method: http.MethodGet, responseCode: 500, errorText: "Internal Server Error"},
		{client: Client{maxRetries: 3}, countedCalls: 4, method: http.MethodPost, responseCode: 503, errorText: "Service Unavailable"},
		{client: Client{maxRetries: 1}, countedCalls: 2, method: http.MethodPut, responseCode: 506, errorText: "Variant Also Negotiates"},
		{client: Client{maxRetries: 1}, countedCalls: 2, method: http.MethodHead, responseCode: 502, errorText: "Bad Gateway"},
		{client: Client{maxRetries: 3}, countedCalls: 1, method: http.MethodHead, responseCode: 404, errorText: "Not Found"},
		{client: Client{maxRetries: 3}, countedCalls: 1, method: http.MethodHead, responseCode: 401, errorText: "Authentication Error"},
		{client: Client{maxRetries: 3}, countedCalls: 1, method: http.MethodHead, responseCode: 403, errorText: "Authorization Error"},
	}

	for _, testCase := range testCases {
		// init
		count := 0
		svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			count++
			if testCase.timeout && count == 0 {
				time.Sleep(3 * time.Microsecond)
			}
			w.WriteHeader(testCase.responseCode)
		}))
		defer svr.Close()
		// test
		_, err := testCase.client.SendRequest(testCase.method, svr.URL, &bytes.Buffer{}, nil, nil)
		// assert
		assert.Error(t, err, fmt.Sprintf("%v: %v", testCase.errorText, "Expected error but did not detect one"))
		assert.Equal(t, testCase.countedCalls, count, fmt.Sprintf("%v: %v", testCase.errorText, "Number of invocations mismatch"))
	}
}

func TestParseHTTPResponseBodyJSON(t *testing.T) {

	type myJSONStruct struct {
		FullName string `json:"full_name"`
		Name     string `json:"name"`
		Owner    struct {
			Login string `json:"login"`
		} `json:"owner"`
	}

	t.Run("parse JSON successful", func(t *testing.T) {

		json := `{"name":"Test Name","full_name":"test full name","owner":{"login": "octocat"}}`
		// create a new reader with that JSON
		r := ioutil.NopCloser(bytes.NewReader([]byte(json)))
		httpResponse := http.Response{
			StatusCode: 200,
			Body:       r,
		}

		var response myJSONStruct
		err := ParseHTTPResponseBodyJSON(&httpResponse, &response)

		if assert.NoError(t, err) {

			t.Run("check correct parsing", func(t *testing.T) {
				assert.Equal(t, myJSONStruct(myJSONStruct{FullName: "test full name", Name: "Test Name", Owner: struct {
					Login string "json:\"login\""
				}{Login: "octocat"}}), response)
			})

		}
	})

	t.Run("http response is nil", func(t *testing.T) {

		var response myJSONStruct
		err := ParseHTTPResponseBodyJSON(nil, &response)

		t.Run("check error", func(t *testing.T) {
			assert.EqualError(t, err, "cannot parse HTTP response with value <nil>")
		})

	})

	t.Run("wrong JSON formatting", func(t *testing.T) {

		json := `{"name":"Test Name","full_name":"test full name";"owner":{"login": "octocat"}}`
		r := ioutil.NopCloser(bytes.NewReader([]byte(json)))
		httpResponse := http.Response{
			StatusCode: 200,
			Body:       r,
		}

		var response myJSONStruct
		err := ParseHTTPResponseBodyJSON(&httpResponse, &response)
		println(response.FullName)

		t.Run("check error", func(t *testing.T) {
			assert.EqualError(t, err, "HTTP response body could not be parsed as JSON: {\"name\":\"Test Name\",\"full_name\":\"test full name\";\"owner\":{\"login\": \"octocat\"}}: invalid character ';' after object key:value pair")
		})

	})

	t.Run("IO read error", func(t *testing.T) {

		mockReadCloser := mockReadCloser{}
		// if Read is called, it will return error
		mockReadCloser.On("Read", mock.AnythingOfType("[]uint8")).Return(0, fmt.Errorf("error reading"))
		// if Close is called, it will return error
		mockReadCloser.On("Close").Return(fmt.Errorf("error closing"))

		httpResponse := http.Response{
			StatusCode: 200,
			Body:       &mockReadCloser,
		}

		var response myJSONStruct
		err := ParseHTTPResponseBodyJSON(&httpResponse, &response)

		t.Run("check error", func(t *testing.T) {
			assert.EqualError(t, err, "HTTP response body could not be read: error reading")
		})

	})

}

func TestParseHTTPResponseBodyXML(t *testing.T) {

	type myXMLStruct struct {
		XMLName xml.Name `xml:"service"`
		Text    string   `xml:",chardata"`
		App     string   `xml:"app,attr"`
		Atom    string   `xml:"atom,attr"`
	}

	t.Run("parse XML successful", func(t *testing.T) {

		myXML := `
		<?xml version="1.0" encoding="utf-8"?>
		<app:service xmlns:app="http://www.w3.org/2007/app" xmlns:atom="http://www.w3.org/2005/Atom"/>
		`
		// create a new reader with that xml
		r := ioutil.NopCloser(bytes.NewReader([]byte(myXML)))
		httpResponse := http.Response{
			StatusCode: 200,
			Body:       r,
		}

		var response myXMLStruct
		err := ParseHTTPResponseBodyXML(&httpResponse, &response)

		if assert.NoError(t, err) {

			t.Run("check correct parsing", func(t *testing.T) {
				// assert.Equal(t, "<?xml version=\"1.0\" encoding=\"utf-8\"?><app:service xmlns:app=\"http://www.w3.org/2007/app\" xmlns:atom=\"http://www.w3.org/2005/Atom\"/>", response)
				assert.Equal(t, myXMLStruct(myXMLStruct{XMLName: xml.Name{Space: "http://www.w3.org/2007/app", Local: "service"}, Text: "", App: "http://www.w3.org/2007/app", Atom: "http://www.w3.org/2005/Atom"}), response)
			})

		}
	})

	t.Run("http response is nil", func(t *testing.T) {

		var response myXMLStruct
		err := ParseHTTPResponseBodyXML(nil, &response)

		t.Run("check error", func(t *testing.T) {
			assert.EqualError(t, err, "cannot parse HTTP response with value <nil>")
		})

	})

	t.Run("wrong XML formatting", func(t *testing.T) {

		myXML := `
		<?xml version="1.0" encoding="utf-8"?>
		<app:service xmlns:app=http://www.w3.org/2007/app" xmlns:atom="http://www.w3.org/2005/Atom"/>
		`
		r := ioutil.NopCloser(bytes.NewReader([]byte(myXML)))
		httpResponse := http.Response{
			StatusCode: 200,
			Body:       r,
		}

		var response myXMLStruct
		err := ParseHTTPResponseBodyXML(&httpResponse, &response)

		t.Run("check error", func(t *testing.T) {
			assert.EqualError(t, err, "HTTP response body could not be parsed as XML: \n\t\t<?xml version=\"1.0\" encoding=\"utf-8\"?>\n\t\t<app:service xmlns:app=http://www.w3.org/2007/app\" xmlns:atom=\"http://www.w3.org/2005/Atom\"/>\n\t\t: XML syntax error on line 3: unquoted or missing attribute value in element")
		})

	})

	t.Run("IO read error", func(t *testing.T) {

		mockReadCloser := mockReadCloser{}
		// if Read is called, it will return error
		mockReadCloser.On("Read", mock.AnythingOfType("[]uint8")).Return(0, fmt.Errorf("error reading"))
		// if Close is called, it will return error
		mockReadCloser.On("Close").Return(fmt.Errorf("error closing"))

		httpResponse := http.Response{
			StatusCode: 200,
			Body:       &mockReadCloser,
		}

		var response myXMLStruct
		err := ParseHTTPResponseBodyXML(&httpResponse, &response)

		t.Run("check error", func(t *testing.T) {
			assert.EqualError(t, err, "HTTP response body could not be read: error reading")
		})

	})

}

type mockReadCloser struct {
	mock.Mock
}

func (m *mockReadCloser) Read(p []byte) (n int, err error) {
	args := m.Called(p)
	return args.Int(0), args.Error(1)
}

func (m *mockReadCloser) Close() error {
	args := m.Called()
	return args.Error(0)
}