Make underlying httpClient configurable

Author: erickearns

client.go

@@ -7,7 +7,6 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"net"
 	"net/http"
 	"net/url"
 	"reflect"
@@ -31,23 +30,6 @@ var (
 	contextType = reflect.TypeOf(new(context.Context)).Elem()
 
 	log = logging.Logger("rpc")
-
-	_defaultHTTPClient = &http.Client{
-		Transport: &http.Transport{
-			Proxy: http.ProxyFromEnvironment,
-			DialContext: (&net.Dialer{
-				Timeout:   30 * time.Second,
-				KeepAlive: 30 * time.Second,
-				DualStack: true,
-			}).DialContext,
-			ForceAttemptHTTP2:     true,
-			MaxIdleConns:          100,
-			MaxIdleConnsPerHost:   100,
-			IdleConnTimeout:       90 * time.Second,
-			TLSHandshakeTimeout:   10 * time.Second,
-			ExpectContinueTimeout: 1 * time.Second,
-		},
-	}
 )
 
 // ErrClient is an error which occurred on the client side the library
@@ -160,7 +142,7 @@ func httpClient(ctx context.Context, addr string, namespace string, outs []inter
 
 		hreq.Header.Set("Content-Type", "application/json")
 
-		httpResp, err := _defaultHTTPClient.Do(hreq)
+		httpResp, err := config.httpClient.Do(hreq)
 		if err != nil {
 			return clientResponse{}, &RPCConnectionError{err}
 		}

options.go

@@ -1,6 +1,8 @@
 package jsonrpc
 
 import (
+	"net"
+	"net/http"
 	"reflect"
 	"time"
 
@@ -17,6 +19,8 @@ type Config struct {
 	paramEncoders map[reflect.Type]ParamEncoder
 	errors        *Errors
 
+	httpClient *http.Client
+
 	noReconnect      bool
 	proxyConnFactory func(func() (*websocket.Conn, error)) func() (*websocket.Conn, error) // for testing
 }
@@ -31,6 +35,23 @@ func defaultConfig() Config {
 		timeout:      30 * time.Second,
 
 		paramEncoders: map[reflect.Type]ParamEncoder{},
+
+		httpClient: &http.Client{
+			Transport: &http.Transport{
+				Proxy: http.ProxyFromEnvironment,
+				DialContext: (&net.Dialer{
+					Timeout:   30 * time.Second,
+					KeepAlive: 30 * time.Second,
+					DualStack: true,
+				}).DialContext,
+				ForceAttemptHTTP2:     true,
+				MaxIdleConns:          100,
+				MaxIdleConnsPerHost:   100,
+				IdleConnTimeout:       90 * time.Second,
+				TLSHandshakeTimeout:   10 * time.Second,
+				ExpectContinueTimeout: 1 * time.Second,
+			},
+		},
 	}
 }
 
@@ -75,3 +96,9 @@ func WithErrors(es Errors) func(c *Config) {
 		c.errors = &es
 	}
 }
+
+func WithHTTPClient(h *http.Client) func(c *Config) {
+	return func(c *Config) {
+		c.httpClient = h
+	}
+}