Update nlopes/slack vendor

vendor/github.com/nlopes/slack/slack.go

@@ -5,20 +5,47 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"net/http"
 	"net/url"
 	"os"
 )
 
-var logger stdLogger // A logger that can be set by consumers
-/*
-  Added as a var so that we can change this for testing purposes
-*/
+// Added as a var so that we can change this for testing purposes
 var SLACK_API string = "https://slack.com/api/"
 var SLACK_WEB_API_FORMAT string = "https://%s.slack.com/api/users.admin.%s?t=%s"
 
-type SlackResponse struct {
-	Ok    bool   `json:"ok"`
-	Error string `json:"error"`
+// HTTPClient sets a custom http.Client
+// deprecated: in favor of SetHTTPClient()
+var HTTPClient = &http.Client{}
+
+var customHTTPClient HTTPRequester = HTTPClient
+
+// HTTPRequester defines the minimal interface needed for an http.Client to be implemented.
+//
+// Use it in conjunction with the SetHTTPClient function to allow for other capabilities
+// like a tracing http.Client
+type HTTPRequester interface {
+	Do(*http.Request) (*http.Response, error)
+}
+
+// SetHTTPClient allows you to specify a custom http.Client
+// Use this instead of the package level HTTPClient variable if you want to use a custom client like the
+// Stackdriver Trace HTTPClient https://godoc.org/cloud.google.com/go/trace#HTTPClient
+func SetHTTPClient(client HTTPRequester) {
+	customHTTPClient = client
+}
+
+// ResponseMetadata holds pagination metadata
+type ResponseMetadata struct {
+	Cursor string `json:"next_cursor"`
+}
+
+func (t *ResponseMetadata) initialize() *ResponseMetadata {
+	if t != nil {
+		return t
+	}
+
+	return &ResponseMetadata{}
 }
 
 type AuthTestResponse struct {
@@ -35,41 +62,33 @@ type authTestResponseFull struct {
 }
 
 type Client struct {
-	config struct {
-		token string
+	token      string
+	info       Info
+	debug      bool
+	httpclient HTTPRequester
+}
+
+// Option defines an option for a Client
+type Option func(*Client)
+
+// OptionHTTPClient - provide a custom http client to the slack client.
+func OptionHTTPClient(c HTTPRequester) func(*Client) {
+	return func(s *Client) {
+		s.httpclient = c
 	}
-	info  Info
-	debug bool
 }
 
-// stdLogger is a logger interface compatible with both stdlib and some
-// 3rd party loggers such as logrus.
-type stdLogger interface {
-	Print(...interface{})
-	Printf(string, ...interface{})
-	Println(...interface{})
+// New builds a slack client from the provided token and options.
+func New(token string, options ...Option) *Client {
+	s := &Client{
+		token:      token,
+		httpclient: customHTTPClient,
+	}
 
-	Fatal(...interface{})
-	Fatalf(string, ...interface{})
-	Fatalln(...interface{})
+	for _, opt := range options {
+		opt(s)
+	}
 
-	Panic(...interface{})
-	Panicf(string, ...interface{})
-	Panicln(...interface{})
-
-	Output(int, string) error
-}
-
-// SetLogger let's library users supply a logger, so that api debugging
-// can be logged along with the application's debugging info.
-func SetLogger(l stdLogger) {
-	logger = l
-}
-
-// New creates new Client.
-func New(token string) *Client {
-	s := &Client{}
-	s.config.token = token
 	return s
 }
 
@@ -80,14 +99,19 @@ func (api *Client) AuthTest() (response *AuthTestResponse, error error) {
 
 // AuthTestContext tests if the user is able to do authenticated requests or not with a custom context
 func (api *Client) AuthTestContext(ctx context.Context) (response *AuthTestResponse, error error) {
+	api.Debugf("Challenging auth...")
 	responseFull := &authTestResponseFull{}
-	err := post(ctx, "auth.test", url.Values{"token": {api.config.token}}, responseFull, api.debug)
+	err := postSlackMethod(ctx, api.httpclient, "auth.test", url.Values{"token": {api.token}}, responseFull, api.debug)
 	if err != nil {
+		api.Debugf("failed to test for auth: %s", err)
 		return nil, err
 	}
 	if !responseFull.Ok {
+		api.Debugf("auth response was not Ok: %s", responseFull.Error)
 		return nil, errors.New(responseFull.Error)
 	}
+
+	api.Debugf("Auth challenge was successful with response %+v", responseFull.AuthTestResponse)
 	return &responseFull.AuthTestResponse, nil
 }
 
@@ -97,16 +121,18 @@ func (api *Client) AuthTestContext(ctx context.Context) (response *AuthTestRespo
 func (api *Client) SetDebug(debug bool) {
 	api.debug = debug
 	if debug && logger == nil {
-		logger = log.New(os.Stdout, "nlopes/slack", log.LstdFlags|log.Lshortfile)
+		SetLogger(log.New(os.Stdout, "nlopes/slack", log.LstdFlags|log.Lshortfile))
 	}
 }
 
+// Debugf print a formatted debug line.
 func (api *Client) Debugf(format string, v ...interface{}) {
 	if api.debug {
 		logger.Output(2, fmt.Sprintf(format, v...))
 	}
 }
 
+// Debugln print a debug line.
 func (api *Client) Debugln(v ...interface{}) {
 	if api.debug {
 		logger.Output(2, fmt.Sprintln(v...))