Add HTTP client middleware handler wrapper

aws · Jun 3, 2020 · b83805c · b83805c
1 parent 06bc5ae
commit b83805c
Showing 1 changed file with 55 additions and 0 deletions.
diff --git a/transport/http/client.go b/transport/http/client.go
@@ -0,0 +1,55 @@
+package http
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/awslabs/smithy-go/middleware"
+)
+
+// ClientDo provides the interface for custom HTTP client implementations.
+type ClientDo interface {
+	Do(*http.Request) (*http.Response, error)
+}
+
+// ClientDoFunc provides a helper to wrap an function as an HTTP client for
+// round tripping requests.
+type ClientDoFunc func(*http.Request) (*http.Response, error)
+
+// Do will invoke the underlying func, returning the result.
+func (fn ClientDoFunc) Do(r *http.Request) (*http.Response, error) {
+	return fn(r)
+}
+
+// ClientHandler wraps a client that implements the HTTP Do method. Standard
+// implementation is http.Client.
+type ClientHandler struct {
+	client ClientDo
+}
+
+// NewClientHandler returns an initialized middleware handler for the client.
+func NewClientHandler(client ClientDo) ClientHandler {
+	return ClientHandler{
+		client: client,
+	}
+}
+
+// Handle implements the middleware Handler interface, that will invoke the
+// underlying HTTP client. Requires the input to be an Smithy *Request. Returns
+// a smithy *Response, or error if the request failed.
+func (c ClientHandler) Handle(ctx context.Context, input interface{}) (
+	out interface{}, metadata middleware.Metadata, err error,
+) {
+	req, ok := input.(*Request)
+	if !ok {
+		return nil, metadata, fmt.Errorf("expect Smithy http.Request value as input, got unsupported type %T", input)
+	}
+
+	resp, err := c.client.Do(req.Build(ctx))
+	if err != nil {
+		return nil, metadata, err
+	}
+
+	return &Response{Response: resp}, metadata, nil
+}