From 21d6e576bc3d0c3d18420ab37ff3dfc90d155530 Mon Sep 17 00:00:00 2001
From: Wito Chandra <wito.chandra@go-jek.com>
Date: Sun, 8 Nov 2020 17:57:28 +0700
Subject: [PATCH] support http head

---
 httpclient/client.go           | 12 ++++++++++++
 httpclient/client_test.go      | 26 ++++++++++++++++++++++++++
 hystrix/hystrix_client.go      | 12 ++++++++++++
 hystrix/hystrix_client_test.go | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 84 insertions(+)

diff --git a/httpclient/client.go b/httpclient/client.go
index 5f03c5b..188e7aa 100644
--- a/httpclient/client.go
+++ b/httpclient/client.go
@@ -120,6 +120,18 @@ func (c *Client) Delete(url string, headers http.Header) (*http.Response, error)
 	return c.Do(request)
 }
 
+// Head makes a HTTP HEAD request with provided URL
+func (c *Client) Head(url string, headers http.Header) (*http.Response, error) {
+	request, err := http.NewRequest(http.MethodHead, url, nil)
+	if err != nil {
+		return nil, errors.Wrap(err, "HEAD - request creation failed")
+	}
+
+	request.Header = headers
+
+	return c.Do(request)
+}
+
 // Do makes an HTTP request with the native `http.Do` interface
 func (c *Client) Do(request *http.Request) (*http.Response, error) {
 	request.Close = true
diff --git a/httpclient/client_test.go b/httpclient/client_test.go
index dbca35d..7cbc6e0 100644
--- a/httpclient/client_test.go
+++ b/httpclient/client_test.go
@@ -131,6 +131,32 @@ func TestHTTPClientDeleteSuccess(t *testing.T) {
 	assert.Equal(t, "{ \"response\": \"ok\" }", respBody(t, response))
 }
 
+func TestHTTPClientHeadSuccess(t *testing.T) {
+	client := NewClient(WithHTTPTimeout(10 * time.Millisecond))
+
+	dummyHandler := func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, http.MethodHead, r.Method)
+		assert.Equal(t, "application/json", r.Header.Get("Content-Type"))
+		assert.Equal(t, "en", r.Header.Get("Accept-Language"))
+
+		w.Header().Add("x-foo", "bar")
+		w.WriteHeader(http.StatusOK)
+	}
+
+	server := httptest.NewServer(http.HandlerFunc(dummyHandler))
+	defer server.Close()
+
+	headers := http.Header{}
+	headers.Set("Content-Type", "application/json")
+	headers.Set("Accept-Language", "en")
+
+	response, err := client.Head(server.URL, headers)
+	require.NoError(t, err, "should not have failed to make a HEAD request")
+
+	assert.Equal(t, http.StatusOK, response.StatusCode)
+	assert.Equal(t, "bar", response.Header.Get("x-foo"))
+}
+
 func TestHTTPClientPutSuccess(t *testing.T) {
 	client := NewClient(WithHTTPTimeout(10 * time.Millisecond))
 
diff --git a/hystrix/hystrix_client.go b/hystrix/hystrix_client.go
index 01c0ca3..513b2a8 100644
--- a/hystrix/hystrix_client.go
+++ b/hystrix/hystrix_client.go
@@ -165,6 +165,18 @@ func (hhc *Client) Delete(url string, headers http.Header) (*http.Response, erro
 	return hhc.Do(request)
 }
 
+// Head makes a HTTP HEAD request with provided URL
+func (hhc *Client) Head(url string, headers http.Header) (*http.Response, error) {
+	request, err := http.NewRequest(http.MethodHead, url, nil)
+	if err != nil {
+		return nil, errors.Wrap(err, "HEAD - request creation failed")
+	}
+
+	request.Header = headers
+
+	return hhc.Do(request)
+}
+
 // Do makes an HTTP request with the native `http.Do` interface
 func (hhc *Client) Do(request *http.Request) (*http.Response, error) {
 	var response *http.Response
diff --git a/hystrix/hystrix_client_test.go b/hystrix/hystrix_client_test.go
index 65a7bbd..e49c92f 100644
--- a/hystrix/hystrix_client_test.go
+++ b/hystrix/hystrix_client_test.go
@@ -171,6 +171,40 @@ func TestHystrixHTTPClientDeleteSuccess(t *testing.T) {
 	assert.Equal(t, "{ \"response\": \"ok\" }", respBody(t, response))
 }
 
+func TestHystrixHTTPClientHeadSuccess(t *testing.T) {
+	client := NewClient(
+		WithHTTPTimeout(10*time.Millisecond),
+		WithCommandName("head_command"),
+		WithHystrixTimeout(10*time.Millisecond),
+		WithMaxConcurrentRequests(100),
+		WithErrorPercentThreshold(10),
+		WithSleepWindow(100),
+		WithRequestVolumeThreshold(10),
+	)
+
+	dummyHandler := func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, http.MethodHead, r.Method)
+		assert.Equal(t, "application/json", r.Header.Get("Content-Type"))
+		assert.Equal(t, "en", r.Header.Get("Accept-Language"))
+
+		w.Header().Add("x-foo", "bar")
+		w.WriteHeader(http.StatusOK)
+	}
+
+	server := httptest.NewServer(http.HandlerFunc(dummyHandler))
+	defer server.Close()
+
+	headers := http.Header{}
+	headers.Set("Content-Type", "application/json")
+	headers.Set("Accept-Language", "en")
+
+	response, err := client.Head(server.URL, headers)
+	require.NoError(t, err, "should not have failed to make a HEAD request")
+
+	assert.Equal(t, http.StatusOK, response.StatusCode)
+	assert.Equal(t, "bar", response.Header.Get("x-foo"))
+}
+
 func TestHystrixHTTPClientPutSuccess(t *testing.T) {
 	client := NewClient(
 		WithHTTPTimeout(10*time.Millisecond),