feat(enhancement): add missing SetHeaderAuthorizationKey from the mutex implementation and the flow of it (#947)

Author: jeevatkm

client.go

@@ -527,6 +527,16 @@ func (c *Client) HeaderAuthorizationKey() string {
 	return c.headerAuthorizationKey
 }
 
+// SetHeaderAuthorizationKey method sets the given HTTP header name for Authorization in the client instance.
+//
+//	client.SetHeaderAuthorizationKey("X-Custom-Authorization")
+func (c *Client) SetHeaderAuthorizationKey(k string) *Client {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	c.headerAuthorizationKey = k
+	return c
+}
+
 // SetAuthToken method sets the auth token of the `Authorization` header for all HTTP requests.
 // The default auth scheme is `Bearer`; it can be customized with the method [Client.SetAuthScheme]. For Example:
 //
@@ -635,6 +645,7 @@ func (c *Client) R() *Request {
 		AllowMethodGetPayload:      c.allowMethodGetPayload,
 		AllowMethodDeletePayload:   c.allowMethodDeletePayload,
 		AllowNonIdempotentRetry:    c.allowNonIdempotentRetry,
+		HeaderAuthorizationKey:     c.headerAuthorizationKey,
 
 		client:              c,
 		baseURL:             c.baseURL,

client_test.go

@@ -524,6 +524,10 @@ func TestClientSettingsCoverage(t *testing.T) {
 	c.SetAuthToken(authToken)
 	assertEqual(t, authToken, c.AuthToken())
 
+	customAuthHeader := "X-Custom-Authorization"
+	c.SetHeaderAuthorizationKey(customAuthHeader)
+	assertEqual(t, customAuthHeader, c.HeaderAuthorizationKey())
+
 	c.SetCloseConnection(true)
 
 	c.DisableDebug()

middleware.go

@@ -284,7 +284,7 @@ func addCredentials(c *Client, r *Request) error {
 	// Build the token Auth header
 	if !isStringEmpty(r.AuthToken) {
 		credentialsAdded = true
-		r.RawRequest.Header.Set(c.HeaderAuthorizationKey(), r.AuthScheme+" "+r.AuthToken)
+		r.RawRequest.Header.Set(r.HeaderAuthorizationKey, r.AuthScheme+" "+r.AuthToken)
 	}
 
 	if !c.IsDisableWarn() && credentialsAdded {

request.go

@@ -62,6 +62,7 @@ type Request struct {
 	IsDone                     bool
 	IsSaveResponse             bool
 	Timeout                    time.Duration
+	HeaderAuthorizationKey     string
 	RetryCount                 int
 	RetryWaitTime              time.Duration
 	RetryMaxWaitTime           time.Duration