THRIFT-4448: Golang: do something with context.Context. Remove Go1.6 compatibility.
Client: go

This closes #1459
diff --git a/test/go/src/common/context_test.go b/test/go/src/common/context_test.go
new file mode 100644
index 0000000..e64dbb9
--- /dev/null
+++ b/test/go/src/common/context_test.go
@@ -0,0 +1,98 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package common
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"syscall"
+	"testing"
+	"thrift"
+	"time"
+)
+
+type slowHttpHandler struct{}
+
+func (slowHttpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	time.Sleep(1 * time.Second)
+}
+
+func TestHttpContextTimeout(t *testing.T) {
+	certPath = "../../../keys"
+
+	unit := test_unit{"127.0.0.1", 9096, "", "http", "binary", false}
+
+	server := &http.Server{Addr: unit.host + fmt.Sprintf(":%d", unit.port), Handler: slowHttpHandler{}}
+	go server.ListenAndServe()
+
+	client, trans, err := StartClient(unit.host, unit.port, unit.domain_socket, unit.transport, unit.protocol, unit.ssl)
+	if err != nil {
+		t.Errorf("Unable to start client: %v", err)
+		return
+	}
+	defer trans.Close()
+
+	unwrapErr := func(err error) error {
+		for {
+			switch err.(type) {
+			case thrift.TTransportException:
+				err = err.(thrift.TTransportException).Err()
+			case *url.Error:
+				err = err.(*url.Error).Err
+			case *net.OpError:
+				err = err.(*net.OpError).Err
+			case *os.SyscallError:
+				err = err.(*os.SyscallError).Err
+			default:
+				return err
+			}
+		}
+	}
+
+	serverStartupDeadline := time.Now().Add(5 * time.Second)
+	for {
+		ctx, _ := context.WithTimeout(context.Background(), 50*time.Millisecond)
+		err = client.TestVoid(ctx)
+		err = unwrapErr(err)
+		if err != syscall.ECONNREFUSED || time.Now().After(serverStartupDeadline) {
+			break
+		}
+		time.Sleep(time.Millisecond)
+	}
+
+	if err == nil {
+		t.Errorf("Request completed (should have timed out)")
+		return
+	}
+
+	// We've got to switch on `err.Error()` here since go1.7 doesn't properly return
+	// `context.DeadlineExceeded` error and `http.errRequestCanceled` is not exported.
+	// See https://github.com/golang/go/issues/17711
+	switch err.Error() {
+	case context.DeadlineExceeded.Error(), "net/http: request canceled":
+		// Expected error
+	default:
+		t.Errorf("Unexpected error: %s", err)
+	}
+}