From 22c6e9d1bd55ca29e3b7b2feba7e131906c5d01b Mon Sep 17 00:00:00 2001
From: JBP <2850825+jybp@users.noreply.github.com>
Date: Fri, 16 Aug 2019 21:28:25 +0200
Subject: [PATCH 1/4] wip integration bidding

---
 browse.go                        |   4 +-
 ebay.go                          |  16 +--
 ebay_test.go                     |   5 +-
 offer.go                         |  47 +++++++++
 test/integration/auction_test.go | 163 +++++++++++++++++++++++++++++++
 test/integration/ebay_test.go    |  70 -------------
 tokensource/tokensource.go       |  27 +++++
 7 files changed, 251 insertions(+), 81 deletions(-)
 create mode 100644 test/integration/auction_test.go
 delete mode 100644 test/integration/ebay_test.go
 create mode 100644 tokensource/tokensource.go

diff --git a/browse.go b/browse.go
index 3c0da4b..b7733fa 100644
--- a/browse.go
+++ b/browse.go
@@ -8,12 +8,12 @@ import (
 	"time"
 )
 
-// BrowseService handles communication with the Browse API
+// BrowseService handles communication with the Browse API.
 //
 // eBay API docs: https://developer.ebay.com/api-docs/buy/browse/overview.html
 type BrowseService service
 
-// Valid values of the "buyingOptions" array for items.
+// Valid values for the "buyingOptions" item field.
 const (
 	BrowseBuyingOptionAuction    = "AUCTION"
 	BrowseBuyingOptionFixedPrice = "FIXED_PRICE"
diff --git a/ebay.go b/ebay.go
index a0583f7..e8659b6 100644
--- a/ebay.go
+++ b/ebay.go
@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"net/http/httputil"
 	"net/url"
 	"strings"
 
@@ -102,7 +103,7 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) error
 		return errors.WithStack(err)
 	}
 	defer resp.Body.Close()
-	if err := CheckResponse(resp); err != nil {
+	if err := CheckResponse(req, resp); err != nil {
 		return err
 	}
 	if v == nil {
@@ -111,7 +112,7 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) error
 	return errors.WithStack(json.NewDecoder(resp.Body).Decode(v))
 }
 
-// An ErrorData reports one or more errors caused by an API request.
+// ErrorData reports one or more errors caused by an API request.
 //
 // eBay API docs: https://developer.ebay.com/api-docs/static/handling-error-messages.html
 type ErrorData struct {
@@ -129,20 +130,21 @@ type ErrorData struct {
 			Value string `json:"value,omitempty"`
 		} `json:"parameters,omitempty"`
 	} `json:"errors,omitempty"`
-	Response *http.Response
+	Response    *http.Response
+	RequestDump string
 }
 
 func (e *ErrorData) Error() string {
-	return fmt.Sprintf("%s %s: %d %+v", e.Response.Request.Method, e.Response.Request.URL,
-		e.Response.StatusCode, e.Errors)
+	return fmt.Sprintf("%d %s: %+v", e.Response.StatusCode, e.RequestDump, e.Errors)
 }
 
 // CheckResponse checks the API response for errors, and returns them if present.
-func CheckResponse(resp *http.Response) error {
+func CheckResponse(req *http.Request, resp *http.Response) error {
 	if s := resp.StatusCode; 200 <= s && s < 300 {
 		return nil
 	}
-	errorData := &ErrorData{Response: resp}
+	dump, _ := httputil.DumpRequest(req, true)
+	errorData := &ErrorData{Response: resp, RequestDump: string(dump)}
 	_ = json.NewDecoder(resp.Body).Decode(errorData)
 	return errorData
 }
diff --git a/ebay_test.go b/ebay_test.go
index 3d2f311..59eaa1f 100644
--- a/ebay_test.go
+++ b/ebay_test.go
@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"testing"
 
 	"github.com/jybp/ebay"
@@ -24,7 +25,7 @@ func TestNewRequest(t *testing.T) {
 
 func TestCheckResponseNoError(t *testing.T) {
 	resp := &http.Response{StatusCode: 200}
-	assert.Nil(t, ebay.CheckResponse(resp))
+	assert.Nil(t, ebay.CheckResponse(&http.Request{}, resp))
 }
 
 func TestCheckResponse(t *testing.T) {
@@ -53,7 +54,7 @@ func TestCheckResponse(t *testing.T) {
 		]
 	}`
 	resp := &http.Response{StatusCode: 400, Body: ioutil.NopCloser(bytes.NewBufferString(body))}
-	err, ok := ebay.CheckResponse(resp).(*ebay.ErrorData)
+	err, ok := ebay.CheckResponse(&http.Request{URL: &url.URL{}}, resp).(*ebay.ErrorData)
 	assert.True(t, ok)
 	assert.Equal(t, 1, len(err.Errors))
 	assert.Equal(t, 15008, err.Errors[0].ErrorID)
diff --git a/offer.go b/offer.go
index 87ddfbe..3b50cfd 100644
--- a/offer.go
+++ b/offer.go
@@ -1,7 +1,10 @@
 package ebay
 
 import (
+	"context"
+	"fmt"
 	"net/http"
+	"time"
 )
 
 // OfferService handles communication with the Offer API
@@ -22,6 +25,11 @@ const (
 	BuyMarketplaceUSA          = "EBAY_US"
 )
 
+// Valid values for the "auctionStatus" Bidding field.
+const (
+	BiddingAuctionStatusEnded = "ENDED"
+)
+
 // OptBuyMarketplace adds the header containing the marketplace id:
 // https://developer.ebay.com/api-docs/buy/static/ref-marketplace-supported.html
 //
@@ -31,3 +39,42 @@ func OptBuyMarketplace(marketplaceID string) func(*http.Request) {
 		req.Header.Set("X-EBAY-C-MARKETPLACE-ID", marketplaceID)
 	}
 }
+
+// Bidding represents an eBay item bidding.
+type Bidding struct {
+	AuctionStatus  string    `json:"auctionStatus"`
+	AuctionEndDate time.Time `json:"auctionEndDate"`
+	ItemID         string    `json:"itemId"`
+	CurrentPrice   struct {
+		Value    string `json:"value"`
+		Currency string `json:"currency"`
+	} `json:"currentPrice"`
+	BidCount            int  `json:"bidCount"`
+	HighBidder          bool `json:"highBidder"`
+	ReservePriceMet     bool `json:"reservePriceMet"`
+	SuggestedBidAmounts []struct {
+		Value    string `json:"value"`
+		Currency string `json:"currency"`
+	} `json:"suggestedBidAmounts"`
+	CurrentProxyBid struct {
+		ProxyBidID string `json:"proxyBidId"`
+		MaxAmount  struct {
+			Value    string `json:"value"`
+			Currency string `json:"currency"`
+		} `json:"maxAmount"`
+	} `json:"currentProxyBid"`
+}
+
+// GetBidding retrieves the buyer's bidding details on an auction.
+//
+// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding
+func (s *OfferService) GetBidding(ctx context.Context, itemID, marketplaceID string, opts ...Opt) (Item, error) {
+	u := fmt.Sprintf("buy/offer/v1_beta/bidding/%s", itemID)
+	opts = append(opts, OptBuyMarketplace(marketplaceID))
+	req, err := s.client.NewRequest(http.MethodGet, u, opts...)
+	if err != nil {
+		return Item{}, err
+	}
+	var it Item
+	return it, s.client.Do(ctx, req, &it)
+}
diff --git a/test/integration/auction_test.go b/test/integration/auction_test.go
new file mode 100644
index 0000000..42d631b
--- /dev/null
+++ b/test/integration/auction_test.go
@@ -0,0 +1,163 @@
+package integration
+
+import (
+	"context"
+	"crypto/rand"
+	"flag"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	_ "github.com/joho/godotenv/autoload"
+	"github.com/jybp/ebay"
+	"github.com/jybp/ebay/tokensource"
+	"golang.org/x/oauth2"
+	oclientcredentials "golang.org/x/oauth2/clientcredentials"
+)
+
+var (
+	integration  bool
+	clientID     string
+	clientSecret string
+)
+
+func init() {
+	flag.BoolVar(&integration, "integration", false, "run integration tests")
+	flag.Parse()
+	if !integration {
+		return
+	}
+	clientID = os.Getenv("SANDBOX_CLIENT_ID")
+	clientSecret = os.Getenv("SANDBOX_CLIENT_SECRET")
+	if clientID == "" || clientSecret == "" {
+		panic("No SANDBOX_CLIENT_ID or SANDBOX_CLIENT_SECRET. Tests won't run.")
+	}
+}
+
+func TestAuction(t *testing.T) {
+	if !integration {
+		t.SkipNow()
+	}
+
+	// Manually create an auction in the sandbox and copy/paste the url:
+	const auctionURL = "https://www.sandbox.ebay.com/itm/110439278158"
+
+	ctx := context.Background()
+
+	conf := oclientcredentials.Config{
+		ClientID:     clientID,
+		ClientSecret: clientSecret,
+		TokenURL:     "https://api.sandbox.ebay.com/identity/v1/oauth2/token",
+		Scopes:       []string{"https://api.ebay.com/oauth/api_scope"},
+	}
+
+	client := ebay.NewSandboxClient(oauth2.NewClient(ctx, tokensource.New(conf.TokenSource(ctx))))
+
+	lit, err := client.Buy.Browse.GetItemByLegacyID(ctx, auctionURL[strings.LastIndex(auctionURL, "/")+1:])
+	if err != nil {
+		t.Fatalf("%+v", err)
+	}
+	it, err := client.Buy.Browse.GetItem(ctx, lit.ItemID)
+	if err != nil {
+		t.Fatalf("%+v", err)
+	}
+	if testing.Verbose() {
+		t.Logf("item: %+v\n", it)
+	}
+	isAuction := false
+	for _, opt := range it.BuyingOptions {
+		if opt == ebay.BrowseBuyingOptionAuction {
+			isAuction = true
+		}
+	}
+	if !isAuction {
+		t.Fatalf("item %s is not an auction. BuyingOptions are: %+v", it.ItemID, it.BuyingOptions)
+	}
+	if time.Now().UTC().After(it.ItemEndDate) {
+		// t.Fatalf("item %s end date has been reached. ItemEndDate is: %s", it.ItemID, it.ItemEndDate.String())
+	}
+	t.Logf("item %s UniqueBidderCount:%d minimumBidPrice: %+v currentPriceToBid: %+v\n", it.ItemID, it.UniqueBidderCount, it.MinimumPriceToBid, it.CurrentBidPrice)
+
+	// Setup oauth server.
+
+	b := make([]byte, 16)
+	if _, err := io.ReadFull(rand.Reader, b); err != nil {
+		t.Fatalf("%+v", err)
+	}
+	state := url.QueryEscape(string(b))
+	authCodeC := make(chan string)
+	var expiresIn time.Duration
+	http.HandleFunc("/accept", func(rw http.ResponseWriter, r *http.Request) {
+		actualState, err := url.QueryUnescape(r.URL.Query().Get("state"))
+		if err != nil {
+			http.Error(rw, fmt.Sprintf("invalid state: %+v", err), http.StatusBadRequest)
+			return
+		}
+		if string(actualState) != state {
+			http.Error(rw, fmt.Sprintf("invalid state:\nexpected:%s\nactual:%s", state, string(actualState)), http.StatusBadRequest)
+			return
+		}
+		code := r.URL.Query().Get("code")
+		expiresInSeconds, err := strconv.Atoi(r.URL.Query().Get("expires_in"))
+		if err != nil {
+			http.Error(rw, fmt.Sprintf("invalid expires_in: %+v", err), http.StatusBadRequest)
+			return
+		}
+		expiresIn = time.Second * time.Duration(expiresInSeconds)
+		authCodeC <- code
+		t.Logf("The authorization code is %s.\n", code)
+		t.Logf("The authorization code will expire in %s seconds.\n", r.URL.Query().Get("expires_in"))
+		rw.Write([]byte("Accept. You can safely close this tab."))
+	})
+	http.HandleFunc("/policy", func(rw http.ResponseWriter, r *http.Request) {
+		rw.Write([]byte("eBay Sniper Policy"))
+	})
+	http.HandleFunc("/decline", func(rw http.ResponseWriter, r *http.Request) {
+		rw.Write([]byte("Decline. You can safely close this tab."))
+	})
+	go func() {
+		t.Fatal(http.ListenAndServe(":52125", nil))
+	}()
+
+	oauthConf := oauth2.Config{
+		ClientID:     clientID,
+		ClientSecret: clientSecret,
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  "https://auth.sandbox.ebay.com/oauth2/authorize",
+			TokenURL: "https://api.sandbox.ebay.com/identity/v1/oauth2/token",
+		},
+		RedirectURL: "Jean-Baptiste_P-JeanBapt-testgo-cowrprk",
+		Scopes:      []string{"https://api.ebay.com/oauth/api_scope/buy.offer.auction"},
+	}
+
+	url := oauthConf.AuthCodeURL(state)
+	fmt.Printf("Visit the URL: %v\n", url)
+
+	authCode := <-authCodeC
+
+	tok, err := oauthConf.Exchange(ctx, authCode)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Force token regen.
+
+	// tok.Expiry = time.Now().Add(-time.Hour * 24) // not working?
+
+	fmt.Printf("Sleeping %v so token expires\n", expiresIn)
+	time.Sleep(expiresIn + time.Second*5)
+
+	client = ebay.NewSandboxClient(oauth2.NewClient(ctx, tokensource.New(oauthConf.TokenSource(ctx, tok))))
+
+	bidding, err := client.Buy.Offer.GetBidding(ctx, it.ItemID, ebay.BuyMarketplaceUSA)
+	if err != nil {
+		t.Fatalf("%+v", err)
+	}
+	t.Logf("item %s bidding: %+v\n", it.ItemID, bidding)
+}
diff --git a/test/integration/ebay_test.go b/test/integration/ebay_test.go
deleted file mode 100644
index 8f339f0..0000000
--- a/test/integration/ebay_test.go
+++ /dev/null
@@ -1,70 +0,0 @@
-package integration
-
-import (
-	"context"
-	"flag"
-	"os"
-	"strings"
-	"testing"
-	"time"
-
-	_ "github.com/joho/godotenv/autoload"
-	"github.com/jybp/ebay"
-	"github.com/jybp/ebay/clientcredentials"
-)
-
-var (
-	integration bool
-	client      *ebay.Client
-)
-
-func init() {
-	flag.BoolVar(&integration, "integration", false, "run integration tests")
-	clientID := os.Getenv("SANDBOX_CLIENT_ID")
-	clientSecret := os.Getenv("SANDBOX_CLIENT_SECRET")
-	if clientID == "" || clientSecret == "" {
-		panic("No SANDBOX_CLIENT_ID or SANDBOX_CLIENT_SECRET. Tests won't run.")
-	}
-	conf := clientcredentials.Config{
-		ClientID:     clientID,
-		ClientSecret: clientSecret,
-		TokenURL:     "https://api.sandbox.ebay.com/identity/v1/oauth2/token",
-		Scopes:       []string{"https://api.ebay.com/oauth/api_scope"},
-	}
-	client = ebay.NewSandboxClient(conf.Client(context.Background()))
-}
-
-func TestAuction(t *testing.T) {
-	if !integration {
-		t.SkipNow()
-	}
-
-	// Manually create an auction in the sandbox and copy/paste the url:
-	const url = "https://www.sandbox.ebay.com/itm/110439278158"
-
-	ctx := context.Background()
-	lit, err := client.Buy.Browse.GetItemByLegacyID(ctx, url[strings.LastIndex(url, "/")+1:])
-	if err != nil {
-		t.Fatalf("%+v", err)
-	}
-	it, err := client.Buy.Browse.GetItem(ctx, lit.ItemID)
-	if err != nil {
-		t.Fatalf("%+v", err)
-	}
-	if testing.Verbose() {
-		t.Logf("item: %+v", it)
-	}
-	isAuction := false
-	for _, opt := range it.BuyingOptions {
-		if opt == ebay.BrowseBuyingOptionAuction {
-			isAuction = true
-		}
-	}
-	if !isAuction {
-		t.Fatalf("item %s is not an auction. BuyingOptions are: %+v", it.ItemID, it.BuyingOptions)
-	}
-	if time.Now().UTC().After(it.ItemEndDate) {
-		t.Fatalf("item %s end date has been reached. ItemEndDate is: %s", it.ItemID, it.ItemEndDate.String())
-	}
-	t.Logf("item %s UniqueBidderCount:%d minimumBidPrice: %+v currentPriceToBid: %+v", it.ItemID, it.UniqueBidderCount, it.MinimumPriceToBid, it.CurrentBidPrice)
-}
diff --git a/tokensource/tokensource.go b/tokensource/tokensource.go
new file mode 100644
index 0000000..36f2e2b
--- /dev/null
+++ b/tokensource/tokensource.go
@@ -0,0 +1,27 @@
+package tokensource
+
+import "golang.org/x/oauth2"
+
+// type TokenSource interface {
+// 	// Token returns a token or an error.
+// 	// Token must be safe for concurrent use by multiple goroutines.
+// 	// The returned Token must not be modified.
+// 	Token() (*Token, error)
+// }
+
+type TokenSource struct {
+	base oauth2.TokenSource
+}
+
+func New(base oauth2.TokenSource) *TokenSource {
+	return &TokenSource{base: base}
+}
+
+func (ts *TokenSource) Token() (*oauth2.Token, error) {
+	t, err := ts.base.Token()
+	if t != nil {
+		print("new token: " + t.AccessToken + "\n") // TODO remove
+		t.TokenType = "Bearer"
+	}
+	return t, err
+}

From 1fb075c056567638566198dac348cb47c36b9b62 Mon Sep 17 00:00:00 2001
From: JBP <2850825+jybp@users.noreply.github.com>
Date: Sat, 17 Aug 2019 12:18:23 +0200
Subject: [PATCH 2/4] Add more GetBidding test and IsError

---
 Makefile                         |  2 +-
 browse.go                        |  6 +--
 ebay.go                          | 80 +++++++++++++++++++++++---------
 ebay_test.go                     | 48 +++++++++++++++----
 offer.go                         | 68 ++++++++++++++++++++++++++-
 offer_test.go                    | 16 +++++++
 test/integration/auction_test.go | 32 ++++---------
 tokensource/tokensource.go       |  1 -
 8 files changed, 193 insertions(+), 60 deletions(-)

diff --git a/Makefile b/Makefile
index 5587572..7f5384a 100644
--- a/Makefile
+++ b/Makefile
@@ -4,4 +4,4 @@ test:
 
 .PHONY: integration
 integration:
-	go test -count=1 -v -run "Auction" ./test/integration -integration=true
\ No newline at end of file
+	go test -count=1 -v -run "Auction" ./test/integration -integration=true -timeout=999999s
\ No newline at end of file
diff --git a/browse.go b/browse.go
index b7733fa..c09d9c8 100644
--- a/browse.go
+++ b/browse.go
@@ -160,7 +160,7 @@ type LegacyItem struct {
 // eBay API docs: https://developer.ebay.com/api-docs/buy/browse/resources/item/methods/getItemByLegacyId
 func (s *BrowseService) GetItemByLegacyID(ctx context.Context, itemLegacyID string, opts ...Opt) (CompactItem, error) {
 	u := fmt.Sprintf("buy/browse/v1/item/get_item_by_legacy_id?legacy_item_id=%s", itemLegacyID)
-	req, err := s.client.NewRequest(http.MethodGet, u, opts...)
+	req, err := s.client.NewRequest(http.MethodGet, u, nil, opts...)
 	if err != nil {
 		return CompactItem{}, err
 	}
@@ -190,7 +190,7 @@ type CompactItem struct {
 // eBay API docs: https://developer.ebay.com/api-docs/buy/browse/resources/item/methods/getItem
 func (s *BrowseService) GetCompactItem(ctx context.Context, itemID string, opts ...Opt) (CompactItem, error) {
 	u := fmt.Sprintf("buy/browse/v1/item/%s?fieldgroups=COMPACT", itemID)
-	req, err := s.client.NewRequest(http.MethodGet, u, opts...)
+	req, err := s.client.NewRequest(http.MethodGet, u, nil, opts...)
 	if err != nil {
 		return CompactItem{}, err
 	}
@@ -368,7 +368,7 @@ type Item struct {
 // eBay API docs: https://developer.ebay.com/api-docs/buy/browse/resources/item/methods/getItem
 func (s *BrowseService) GetItem(ctx context.Context, itemID string, opts ...Opt) (Item, error) {
 	u := fmt.Sprintf("buy/browse/v1/item/%s?fieldgroups=PRODUCT", itemID)
-	req, err := s.client.NewRequest(http.MethodGet, u, opts...)
+	req, err := s.client.NewRequest(http.MethodGet, u, nil, opts...)
 	if err != nil {
 		return Item{}, err
 	}
diff --git a/ebay.go b/ebay.go
index e8659b6..3a540d2 100644
--- a/ebay.go
+++ b/ebay.go
@@ -1,9 +1,11 @@
 package ebay
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/httputil"
 	"net/url"
@@ -78,7 +80,7 @@ type Opt func(*http.Request)
 
 // NewRequest creates an API request.
 // url should always be specified without a preceding slash.
-func (c *Client) NewRequest(method, url string, opts ...Opt) (*http.Request, error) {
+func (c *Client) NewRequest(method, url string, body interface{}, opts ...Opt) (*http.Request, error) {
 	if strings.HasPrefix(url, "/") {
 		return nil, errors.New("url should always be specified without a preceding slash")
 	}
@@ -86,7 +88,16 @@ func (c *Client) NewRequest(method, url string, opts ...Opt) (*http.Request, err
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
-	req, err := http.NewRequest(method, u.String(), nil)
+	var buf io.ReadWriter
+	if body != nil {
+		buf = new(bytes.Buffer)
+		enc := json.NewEncoder(buf)
+		enc.SetEscapeHTML(false)
+		if err := enc.Encode(body); err != nil {
+			return nil, err
+		}
+	}
+	req, err := http.NewRequest(method, u.String(), buf)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -112,30 +123,36 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) error
 	return errors.WithStack(json.NewDecoder(resp.Body).Decode(v))
 }
 
-// ErrorData reports one or more errors caused by an API request.
+// Error describes one error caused by an eBay API request.
+//
+// eBay API docs: https://developer.ebay.com/api-docs/static/handling-error-messages.html
+type Error struct {
+	ErrorID     int      `json:"errorId,omitempty"`
+	Domain      string   `json:"domain,omitempty"`
+	SubDomain   string   `json:"subDomain,omitempty"`
+	Category    string   `json:"category,omitempty"`
+	Message     string   `json:"message,omitempty"`
+	LongMessage string   `json:"longMessage,omitempty"`
+	InputRefIds []string `json:"inputRefIds,omitempty"`
+	OuputRefIds []string `json:"outputRefIds,omitempty"`
+	Parameters  []struct {
+		Name  string `json:"name,omitempty"`
+		Value string `json:"value,omitempty"`
+	} `json:"parameters,omitempty"`
+}
+
+// ErrorData describes one or more errors caused by an eBay API request.
 //
 // eBay API docs: https://developer.ebay.com/api-docs/static/handling-error-messages.html
 type ErrorData struct {
-	Errors []struct {
-		ErrorID     int      `json:"errorId,omitempty"`
-		Domain      string   `json:"domain,omitempty"`
-		SubDomain   string   `json:"subDomain,omitempty"`
-		Category    string   `json:"category,omitempty"`
-		Message     string   `json:"message,omitempty"`
-		LongMessage string   `json:"longMessage,omitempty"`
-		InputRefIds []string `json:"inputRefIds,omitempty"`
-		OuputRefIds []string `json:"outputRefIds,omitempty"`
-		Parameters  []struct {
-			Name  string `json:"name,omitempty"`
-			Value string `json:"value,omitempty"`
-		} `json:"parameters,omitempty"`
-	} `json:"errors,omitempty"`
-	Response    *http.Response
-	RequestDump string
+	Errors []Error `json:"errors,omitempty"`
+
+	response    *http.Response
+	requestDump string
 }
 
 func (e *ErrorData) Error() string {
-	return fmt.Sprintf("%d %s: %+v", e.Response.StatusCode, e.RequestDump, e.Errors)
+	return fmt.Sprintf("%d %s: %+v", e.response.StatusCode, e.requestDump, e.Errors)
 }
 
 // CheckResponse checks the API response for errors, and returns them if present.
@@ -144,7 +161,28 @@ func CheckResponse(req *http.Request, resp *http.Response) error {
 		return nil
 	}
 	dump, _ := httputil.DumpRequest(req, true)
-	errorData := &ErrorData{Response: resp, RequestDump: string(dump)}
+	errorData := &ErrorData{response: resp, requestDump: string(dump)}
 	_ = json.NewDecoder(resp.Body).Decode(errorData)
 	return errorData
 }
+
+// IsError allows to check if err is a specific error codes returned by the eBay API.
+//
+// eBay API docs: https://developer.ebay.com/devzone/xml/docs/Reference/ebay/Errors/errormessages.htm
+func IsError(err error, codes ...int) bool {
+	if err == nil {
+		return false
+	}
+	errData, ok := err.(*ErrorData)
+	if !ok {
+		return false
+	}
+	for _, e := range errData.Errors {
+		for _, code := range codes {
+			if e.ErrorID == code {
+				return true
+			}
+		}
+	}
+	return false
+}
diff --git a/ebay_test.go b/ebay_test.go
index 59eaa1f..3e7fe24 100644
--- a/ebay_test.go
+++ b/ebay_test.go
@@ -10,15 +10,28 @@ import (
 	"testing"
 
 	"github.com/jybp/ebay"
+	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 )
 
+// setup sets up a test HTTP server.
+func setup(t *testing.T) (client *ebay.Client, mux *http.ServeMux, teardown func()) {
+	mux = http.NewServeMux()
+	server := httptest.NewServer(mux)
+	var err error
+	client, err = ebay.NewCustomClient(nil, server.URL+"/")
+	if err != nil {
+		t.Fatal(err)
+	}
+	return client, mux, server.Close
+}
+
 func TestNewRequest(t *testing.T) {
 	testOpt := func(r *http.Request) {
 		r.URL.RawQuery = "q=1"
 	}
 	client, _ := ebay.NewCustomClient(nil, "https://api.ebay.com/")
-	r, _ := client.NewRequest(http.MethodPost, "test", testOpt)
+	r, _ := client.NewRequest(http.MethodPost, "test", nil, testOpt)
 	assert.Equal(t, "https://api.ebay.com/test?q=1", fmt.Sprint(r.URL))
 	assert.Equal(t, http.MethodPost, r.Method)
 }
@@ -69,14 +82,29 @@ func TestCheckResponse(t *testing.T) {
 	assert.Equal(t, "2200077988|0", err.Errors[0].Parameters[0].Value)
 }
 
-// setup sets up a test HTTP server
-func setup(t *testing.T) (client *ebay.Client, mux *http.ServeMux, teardown func()) {
-	mux = http.NewServeMux()
-	server := httptest.NewServer(mux)
-	var err error
-	client, err = ebay.NewCustomClient(nil, server.URL+"/")
-	if err != nil {
-		t.Fatal(err)
+func TestIsErrorMatches(t *testing.T) {
+	var err error = &ebay.ErrorData{
+		Errors: []ebay.Error{
+			ebay.Error{ErrorID: 1},
+		},
 	}
-	return client, mux, server.Close
+	assert.True(t, ebay.IsError(err, 1, 2, 3))
+}
+
+func TestIsErrorNoMatches(t *testing.T) {
+	var err error = &ebay.ErrorData{
+		Errors: []ebay.Error{
+			ebay.Error{ErrorID: 4},
+		},
+	}
+	assert.False(t, ebay.IsError(err, 1, 2, 3))
+}
+
+func TestIsErrorWrongType(t *testing.T) {
+	var err error = errors.New("test")
+	assert.False(t, ebay.IsError(err, 1, 2, 3))
+}
+
+func TestIsErrorNil(t *testing.T) {
+	assert.False(t, ebay.IsError(nil, 1, 2, 3))
 }
diff --git a/offer.go b/offer.go
index 3b50cfd..fe920c9 100644
--- a/offer.go
+++ b/offer.go
@@ -65,16 +65,80 @@ type Bidding struct {
 	} `json:"currentProxyBid"`
 }
 
-// GetBidding retrieves the buyer's bidding details on an auction.
+// Some valid eBay error codes for the GetBidding method.
+//
+// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding#h2-error-codes
+const (
+	ErrGetBiddingMarketplaceNotSupported = 120017
+	ErrGetBiddingNoBiddingActivity       = 120033
+)
+
+// GetBidding retrieves the buyer's bidding details on a specific auction item.
 //
 // eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding
 func (s *OfferService) GetBidding(ctx context.Context, itemID, marketplaceID string, opts ...Opt) (Item, error) {
 	u := fmt.Sprintf("buy/offer/v1_beta/bidding/%s", itemID)
 	opts = append(opts, OptBuyMarketplace(marketplaceID))
-	req, err := s.client.NewRequest(http.MethodGet, u, opts...)
+	req, err := s.client.NewRequest(http.MethodGet, u, nil, opts...)
 	if err != nil {
 		return Item{}, err
 	}
 	var it Item
 	return it, s.client.Do(ctx, req, &it)
 }
+
+// ProxyBid represents an eBay proxy bid.
+type ProxyBid struct {
+	ProxyBidID string `json:"proxyBidId"`
+}
+
+// Some valid eBay error codes for the PlaceProxyBid method.
+//
+// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding#h2-error-codes
+const (
+	ErrPlaceProxyBidAuctionEndedBecauseOfBuyItNow       = 120002
+	ErrPlaceProxyBidBidCannotBeGreaterThanBuyItNowPrice = 120005
+	ErrPlaceProxyBidAmountTooHigh                       = 120007
+	ErrPlaceProxyBidAmountTooLow                        = 120008
+	ErrPlaceProxyBidCurrencyMustMatchItemPriceCurrency  = 120009
+	ErrPlaceProxyBidCannotLowerYourProxyBid             = 120010
+	ErrPlaceProxyBidAmountExceedsLimit                  = 120011
+	ErrPlaceProxyBidAuctionHasEnded                     = 120012
+	ErrPlaceProxyBidAmountInvalid                       = 120013
+	ErrPlaceProxyBidCurrencyInvalid                     = 120014
+	ErrPlaceProxyBidMaximumBidAmountMissing             = 120016
+)
+
+// PlaceProxyBid places a proxy bid for the buyer on a specific auction item.
+//
+// You must ensure the user agrees to the "Terms of use for Adult Only category"
+// (https://signin.ebay.com/ws/eBayISAPI.dll?AdultSignIn2) if he wishes to bid on on a adult-only item.
+//
+// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding
+func (s *OfferService) PlaceProxyBid(ctx context.Context, itemID, marketplaceID, maxAmount, currency string, userConsentAdultOnlyItem bool, opts ...Opt) (ProxyBid, error) {
+	u := fmt.Sprintf("buy/offer/v1_beta/bidding/%s/place_proxy_bid", itemID)
+	opts = append(opts, OptBuyMarketplace(marketplaceID))
+	pl := struct {
+		MaxAmount struct {
+			Currency string `json:"currency"`
+			Value    string `json:"value"`
+		} `json:"maxAmount"`
+		UserConsent struct {
+			AdultOnlyItem bool `json:"adultOnlyItem"`
+		} `json:"userConsent"`
+	}{
+		MaxAmount: struct {
+			Currency string `json:"currency"`
+			Value    string `json:"value"`
+		}{currency, maxAmount},
+		UserConsent: struct {
+			AdultOnlyItem bool `json:"adultOnlyItem"`
+		}{userConsentAdultOnlyItem},
+	}
+	req, err := s.client.NewRequest(http.MethodPost, u, &pl, opts...)
+	if err != nil {
+		return ProxyBid{}, err
+	}
+	var p ProxyBid
+	return p, s.client.Do(ctx, req, &p)
+}
diff --git a/offer_test.go b/offer_test.go
index f27066a..c57c305 100644
--- a/offer_test.go
+++ b/offer_test.go
@@ -1,6 +1,8 @@
 package ebay_test
 
 import (
+	"context"
+	"fmt"
 	"net/http"
 	"testing"
 
@@ -13,3 +15,17 @@ func TestOptBuyMarketplace(t *testing.T) {
 	ebay.OptBuyMarketplace("EBAY_US")(r)
 	assert.Equal(t, "EBAY_US", r.Header.Get("X-EBAY-C-MARKETPLACE-ID"))
 }
+
+func TestGetBidding(t *testing.T) {
+	client, mux, teardown := setup(t)
+	defer teardown()
+
+	mux.HandleFunc("/buy/offer/v1_beta/bidding/v1|202117468662|0", func(w http.ResponseWriter, r *http.Request) {
+		marketplaceID := r.Header.Get("X-EBAY-C-MARKETPLACE-ID")
+		fmt.Fprintf(w, `{"itemId": "%s"}`, marketplaceID)
+	})
+
+	bidding, err := client.Buy.Offer.GetBidding(context.Background(), "v1|202117468662|0", ebay.BuyMarketplaceUSA)
+	assert.Nil(t, err)
+	assert.Equal(t, ebay.BuyMarketplaceUSA, bidding.ItemID)
+}
diff --git a/test/integration/auction_test.go b/test/integration/auction_test.go
index 42d631b..fe7f6ae 100644
--- a/test/integration/auction_test.go
+++ b/test/integration/auction_test.go
@@ -9,7 +9,6 @@ import (
 	"net/http"
 	"net/url"
 	"os"
-	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -45,8 +44,9 @@ func TestAuction(t *testing.T) {
 		t.SkipNow()
 	}
 
-	// Manually create an auction in the sandbox and copy/paste the url:
-	const auctionURL = "https://www.sandbox.ebay.com/itm/110439278158"
+	// Manually create an auction in the sandbox and copy/paste the url.
+	// Auctions can't be created using the rest api (yet?).
+	const auctionURL = "https://www.sandbox.ebay.com/itm/110440008951"
 
 	ctx := context.Background()
 
@@ -80,7 +80,7 @@ func TestAuction(t *testing.T) {
 		t.Fatalf("item %s is not an auction. BuyingOptions are: %+v", it.ItemID, it.BuyingOptions)
 	}
 	if time.Now().UTC().After(it.ItemEndDate) {
-		// t.Fatalf("item %s end date has been reached. ItemEndDate is: %s", it.ItemID, it.ItemEndDate.String())
+		t.Fatalf("item %s end date has been reached. ItemEndDate is: %s", it.ItemID, it.ItemEndDate.String())
 	}
 	t.Logf("item %s UniqueBidderCount:%d minimumBidPrice: %+v currentPriceToBid: %+v\n", it.ItemID, it.UniqueBidderCount, it.MinimumPriceToBid, it.CurrentBidPrice)
 
@@ -92,7 +92,6 @@ func TestAuction(t *testing.T) {
 	}
 	state := url.QueryEscape(string(b))
 	authCodeC := make(chan string)
-	var expiresIn time.Duration
 	http.HandleFunc("/accept", func(rw http.ResponseWriter, r *http.Request) {
 		actualState, err := url.QueryUnescape(r.URL.Query().Get("state"))
 		if err != nil {
@@ -104,12 +103,6 @@ func TestAuction(t *testing.T) {
 			return
 		}
 		code := r.URL.Query().Get("code")
-		expiresInSeconds, err := strconv.Atoi(r.URL.Query().Get("expires_in"))
-		if err != nil {
-			http.Error(rw, fmt.Sprintf("invalid expires_in: %+v", err), http.StatusBadRequest)
-			return
-		}
-		expiresIn = time.Second * time.Duration(expiresInSeconds)
 		authCodeC <- code
 		t.Logf("The authorization code is %s.\n", code)
 		t.Logf("The authorization code will expire in %s seconds.\n", r.URL.Query().Get("expires_in"))
@@ -146,18 +139,13 @@ func TestAuction(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// Force token regen.
-
-	// tok.Expiry = time.Now().Add(-time.Hour * 24) // not working?
-
-	fmt.Printf("Sleeping %v so token expires\n", expiresIn)
-	time.Sleep(expiresIn + time.Second*5)
-
 	client = ebay.NewSandboxClient(oauth2.NewClient(ctx, tokensource.New(oauthConf.TokenSource(ctx, tok))))
 
-	bidding, err := client.Buy.Offer.GetBidding(ctx, it.ItemID, ebay.BuyMarketplaceUSA)
-	if err != nil {
-		t.Fatalf("%+v", err)
+	_, err = client.Buy.Offer.GetBidding(ctx, it.ItemID, ebay.BuyMarketplaceUSA)
+	if !ebay.IsError(err, ebay.ErrGetBiddingNoBiddingActivity) {
+		t.Logf("Expected ErrNoBiddingActivity, got %+v.", err)
 	}
-	t.Logf("item %s bidding: %+v\n", it.ItemID, bidding)
+
+	// err := client.Buy.Offer.PlaceProxyBid(ctx)
+
 }
diff --git a/tokensource/tokensource.go b/tokensource/tokensource.go
index 36f2e2b..8bc0291 100644
--- a/tokensource/tokensource.go
+++ b/tokensource/tokensource.go
@@ -20,7 +20,6 @@ func New(base oauth2.TokenSource) *TokenSource {
 func (ts *TokenSource) Token() (*oauth2.Token, error) {
 	t, err := ts.base.Token()
 	if t != nil {
-		print("new token: " + t.AccessToken + "\n") // TODO remove
 		t.TokenType = "Bearer"
 	}
 	return t, err

From ceeafe4fd6c3936df29df6ad6c35365802e159ca Mon Sep 17 00:00:00 2001
From: JBP <2850825+jybp@users.noreply.github.com>
Date: Sat, 17 Aug 2019 15:05:34 +0200
Subject: [PATCH 3/4] Add PlaceProxyBid

---
 Makefile                               |   2 +-
 browse_test.go                         |   9 ++
 clientcredentials/clientcredentials.go | 121 -------------------------
 ebay.go                                |  14 ++-
 oauth2.go                              |  24 +++++
 offer.go                               |  52 ++++++-----
 offer_test.go                          |  34 +++++++
 test/integration/auction_test.go       |  50 ++++++----
 tokensource/tokensource.go             |  26 ------
 9 files changed, 138 insertions(+), 194 deletions(-)
 delete mode 100644 clientcredentials/clientcredentials.go
 create mode 100644 oauth2.go
 delete mode 100644 tokensource/tokensource.go

diff --git a/Makefile b/Makefile
index 7f5384a..5587572 100644
--- a/Makefile
+++ b/Makefile
@@ -4,4 +4,4 @@ test:
 
 .PHONY: integration
 integration:
-	go test -count=1 -v -run "Auction" ./test/integration -integration=true -timeout=999999s
\ No newline at end of file
+	go test -count=1 -v -run "Auction" ./test/integration -integration=true
\ No newline at end of file
diff --git a/browse_test.go b/browse_test.go
index feedf1a..911786c 100644
--- a/browse_test.go
+++ b/browse_test.go
@@ -28,6 +28,9 @@ func TestGetLegacyItem(t *testing.T) {
 	defer teardown()
 
 	mux.HandleFunc("/buy/browse/v1/item/get_item_by_legacy_id", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "GET" {
+			t.Fatalf("expected GET method, got: %s", r.Method)
+		}
 		fmt.Fprintf(w, `{"itemId": "v1|%s|0"}`, r.URL.Query().Get("legacy_item_id"))
 	})
 
@@ -41,6 +44,9 @@ func TestGetCompactItem(t *testing.T) {
 	defer teardown()
 
 	mux.HandleFunc("/buy/browse/v1/item/v1|202117468662|0", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "GET" {
+			t.Fatalf("expected GET method, got: %s", r.Method)
+		}
 		fmt.Fprintf(w, `{"itemId": "%s"}`, r.URL.Query().Get("fieldgroups"))
 	})
 
@@ -54,6 +60,9 @@ func TestGettItem(t *testing.T) {
 	defer teardown()
 
 	mux.HandleFunc("/buy/browse/v1/item/v1|202117468662|0", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "GET" {
+			t.Fatalf("expected GET method, got: %s", r.Method)
+		}
 		fmt.Fprintf(w, `{"itemId": "%s"}`, r.URL.Query().Get("fieldgroups"))
 	})
 
diff --git a/clientcredentials/clientcredentials.go b/clientcredentials/clientcredentials.go
deleted file mode 100644
index 076a4bf..0000000
--- a/clientcredentials/clientcredentials.go
+++ /dev/null
@@ -1,121 +0,0 @@
-// Package clientcredentials implements the eBay client credentials grant flow
-// to generate "Application access" tokens.
-// eBay doc: https://developer.ebay.com/api-docs/static/oauth-client-credentials-grant.html
-//
-// The only difference from the original golang.org/x/oauth2/clientcredentials is the token type
-// being forced to "Bearer". The eBay api /identity/v1/oauth2/token endpoint returns
-// "Application Access Token" as token type which is then reused:
-// https://github.com/golang/oauth2/blob/aaccbc9213b0974828f81aaac109d194880e3014/token.go#L68-L70
-package clientcredentials
-
-import (
-	"bytes"
-	"context"
-	"encoding/json"
-	"fmt"
-	"io/ioutil"
-	"net/http"
-	"net/url"
-	"strings"
-	"time"
-
-	"golang.org/x/oauth2"
-)
-
-type Config struct {
-	// ClientID is the application's ID.
-	ClientID string
-
-	// ClientSecret is the application's secret.
-	ClientSecret string
-
-	// TokenURL is the resource server's token endpoint
-	// URL. This is a constant specific to each server.
-	TokenURL string
-
-	// Scope specifies optional requested permissions.
-	Scopes []string
-
-	// HTTPClient used to make requests.
-	HTTPClient *http.Client
-}
-
-// Token uses client credentials to retrieve a token.
-func (c *Config) Token(ctx context.Context) (*oauth2.Token, error) {
-	return c.TokenSource(ctx).Token()
-}
-
-// Client returns an HTTP client using the provided token.
-// The token will auto-refresh as necessary.
-// The returned client and its Transport should not be modified.
-func (c *Config) Client(ctx context.Context) *http.Client {
-	return oauth2.NewClient(ctx, c.TokenSource(ctx))
-}
-
-// TokenSource returns a TokenSource that returns t until t expires,
-// automatically refreshing it as necessary using the provided context and the
-// client ID and client secret.
-//
-// Most users will use Config.Client instead.
-func (c *Config) TokenSource(ctx context.Context) oauth2.TokenSource {
-	source := &tokenSource{
-		ctx:  ctx,
-		conf: c,
-	}
-	return oauth2.ReuseTokenSource(nil, source)
-}
-
-type tokenSource struct {
-	ctx  context.Context
-	conf *Config
-}
-
-// Token refreshes the token by using a new client credentials request.
-// tokens received this way do not include a refresh token
-func (c *tokenSource) Token() (*oauth2.Token, error) {
-	v := url.Values{
-		"grant_type": {"client_credentials"},
-	}
-	if len(c.conf.Scopes) > 0 {
-		v.Set("scope", strings.Join(c.conf.Scopes, " "))
-	}
-	req, err := http.NewRequest("POST", c.conf.TokenURL, strings.NewReader(v.Encode()))
-	if err != nil {
-		return nil, err
-	}
-	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-	req.SetBasicAuth(url.QueryEscape(c.conf.ClientID), url.QueryEscape(c.conf.ClientSecret))
-	client := c.conf.HTTPClient
-	if client == nil {
-		client = http.DefaultClient
-	}
-	r, err := client.Do(req)
-	if err != nil {
-		return nil, err
-	}
-	defer r.Body.Close()
-	body, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return nil, fmt.Errorf("cannot fetch token: %v", err)
-	}
-	if code := r.StatusCode; code < 200 || code > 299 {
-		return nil, fmt.Errorf("%s (%d)", req.URL, r.StatusCode)
-	}
-	token := struct {
-		AccessToken string `json:"access_token"`
-		ExpiresIn   int    `json:"expires_in"`
-	}{}
-	if err = json.NewDecoder(bytes.NewReader(body)).Decode(&token); err != nil {
-		return nil, err
-	}
-	var expiry time.Time
-	if secs := token.ExpiresIn; secs > 0 {
-		expiry = time.Now().Add(time.Duration(secs) * time.Second)
-	}
-	t := oauth2.Token{
-		AccessToken: token.AccessToken,
-		Expiry:      expiry,
-		TokenType:   "Bearer",
-	}
-	return &t, nil
-}
diff --git a/ebay.go b/ebay.go
index 3a540d2..440cc2e 100644
--- a/ebay.go
+++ b/ebay.go
@@ -88,16 +88,20 @@ func (c *Client) NewRequest(method, url string, body interface{}, opts ...Opt) (
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
-	var buf io.ReadWriter
+	var bodyR io.Reader
 	if body != nil {
-		buf = new(bytes.Buffer)
+		buf := new(bytes.Buffer)
 		enc := json.NewEncoder(buf)
 		enc.SetEscapeHTML(false)
 		if err := enc.Encode(body); err != nil {
 			return nil, err
 		}
+		b := buf.Bytes()
+		print("body:" + string(b)) // TODO
+		bodyR = bytes.NewReader(b)
 	}
-	req, err := http.NewRequest(method, u.String(), buf)
+
+	req, err := http.NewRequest(method, u.String(), bodyR)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -152,7 +156,7 @@ type ErrorData struct {
 }
 
 func (e *ErrorData) Error() string {
-	return fmt.Sprintf("%d %s: %+v", e.response.StatusCode, e.requestDump, e.Errors)
+	return fmt.Sprintf("%d\n%s\n%+v", e.response.StatusCode, e.requestDump, e.Errors)
 }
 
 // CheckResponse checks the API response for errors, and returns them if present.
@@ -166,7 +170,7 @@ func CheckResponse(req *http.Request, resp *http.Response) error {
 	return errorData
 }
 
-// IsError allows to check if err is a specific error codes returned by the eBay API.
+// IsError allows to check if err contains specific error codes returned by the eBay API.
 //
 // eBay API docs: https://developer.ebay.com/devzone/xml/docs/Reference/ebay/Errors/errormessages.htm
 func IsError(err error, codes ...int) bool {
diff --git a/oauth2.go b/oauth2.go
new file mode 100644
index 0000000..0ee357a
--- /dev/null
+++ b/oauth2.go
@@ -0,0 +1,24 @@
+package ebay
+
+import "golang.org/x/oauth2"
+
+// BearerTokenSource forces the type of the token returned by the 'base' TokenSource to 'Bearer'.
+// The eBay API will return "Application Access Token" or "User Access Token" as token_type but
+// it must be set to 'Bearer' for subsequent requests.
+type BearerTokenSource struct {
+	base oauth2.TokenSource
+}
+
+// TokenSource returns a new BearerTokenSource.
+func TokenSource(base oauth2.TokenSource) *BearerTokenSource {
+	return &BearerTokenSource{base: base}
+}
+
+// Token allows BearerTokenSource to implement oauth2.TokenSource.
+func (ts *BearerTokenSource) Token() (*oauth2.Token, error) {
+	t, err := ts.base.Token()
+	if t != nil {
+		t.TokenType = "Bearer"
+	}
+	return t, err
+}
diff --git a/offer.go b/offer.go
index fe920c9..8d6d570 100644
--- a/offer.go
+++ b/offer.go
@@ -76,15 +76,15 @@ const (
 // GetBidding retrieves the buyer's bidding details on a specific auction item.
 //
 // eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding
-func (s *OfferService) GetBidding(ctx context.Context, itemID, marketplaceID string, opts ...Opt) (Item, error) {
+func (s *OfferService) GetBidding(ctx context.Context, itemID, marketplaceID string, opts ...Opt) (Bidding, error) {
 	u := fmt.Sprintf("buy/offer/v1_beta/bidding/%s", itemID)
 	opts = append(opts, OptBuyMarketplace(marketplaceID))
 	req, err := s.client.NewRequest(http.MethodGet, u, nil, opts...)
 	if err != nil {
-		return Item{}, err
+		return Bidding{}, err
 	}
-	var it Item
-	return it, s.client.Do(ctx, req, &it)
+	var bid Bidding
+	return bid, s.client.Do(ctx, req, &bid)
 }
 
 // ProxyBid represents an eBay proxy bid.
@@ -94,7 +94,7 @@ type ProxyBid struct {
 
 // Some valid eBay error codes for the PlaceProxyBid method.
 //
-// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding#h2-error-codes
+// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/placeProxyBid#h2-error-codes
 const (
 	ErrPlaceProxyBidAuctionEndedBecauseOfBuyItNow       = 120002
 	ErrPlaceProxyBidBidCannotBeGreaterThanBuyItNowPrice = 120005
@@ -111,34 +111,38 @@ const (
 
 // PlaceProxyBid places a proxy bid for the buyer on a specific auction item.
 //
+// Curency is the three-letter ISO 4217 code representing the currency.
+// For one hundred US dollars, MaxAmout is "100.00" and currency is "USD".
+//
 // You must ensure the user agrees to the "Terms of use for Adult Only category"
 // (https://signin.ebay.com/ws/eBayISAPI.dll?AdultSignIn2) if he wishes to bid on on a adult-only item.
+// An item is adult-only if the AdultOnly field returned by the Browse API is set to true.
 //
-// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding
+// eBay API docs: https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/placeProxyBid
 func (s *OfferService) PlaceProxyBid(ctx context.Context, itemID, marketplaceID, maxAmount, currency string, userConsentAdultOnlyItem bool, opts ...Opt) (ProxyBid, error) {
 	u := fmt.Sprintf("buy/offer/v1_beta/bidding/%s/place_proxy_bid", itemID)
 	opts = append(opts, OptBuyMarketplace(marketplaceID))
-	pl := struct {
-		MaxAmount struct {
-			Currency string `json:"currency"`
-			Value    string `json:"value"`
-		} `json:"maxAmount"`
-		UserConsent struct {
-			AdultOnlyItem bool `json:"adultOnlyItem"`
-		} `json:"userConsent"`
-	}{
-		MaxAmount: struct {
-			Currency string `json:"currency"`
-			Value    string `json:"value"`
-		}{currency, maxAmount},
-		UserConsent: struct {
-			AdultOnlyItem bool `json:"adultOnlyItem"`
-		}{userConsentAdultOnlyItem},
+	type userConsent struct {
+		AdultOnlyItem bool `json:"adultOnlyItem,omitempty"`
+	}
+	type amount struct {
+		Currency string `json:"currency"`
+		Value    string `json:"value"`
+	}
+	type payload struct {
+		MaxAmount   amount       `json:"maxAmount"`
+		UserConsent *userConsent `json:"userConsent,omitempty"`
+	}
+	pl := payload{
+		MaxAmount: amount{Currency: currency, Value: maxAmount},
+	}
+	if userConsentAdultOnlyItem {
+		pl.UserConsent = &userConsent{userConsentAdultOnlyItem}
 	}
 	req, err := s.client.NewRequest(http.MethodPost, u, &pl, opts...)
 	if err != nil {
 		return ProxyBid{}, err
 	}
-	var p ProxyBid
-	return p, s.client.Do(ctx, req, &p)
+	var bid ProxyBid
+	return bid, s.client.Do(ctx, req, &bid)
 }
diff --git a/offer_test.go b/offer_test.go
index c57c305..5895bbf 100644
--- a/offer_test.go
+++ b/offer_test.go
@@ -3,7 +3,9 @@ package ebay_test
 import (
 	"context"
 	"fmt"
+	"io/ioutil"
 	"net/http"
+	"strconv"
 	"testing"
 
 	"github.com/jybp/ebay"
@@ -21,6 +23,9 @@ func TestGetBidding(t *testing.T) {
 	defer teardown()
 
 	mux.HandleFunc("/buy/offer/v1_beta/bidding/v1|202117468662|0", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "GET" {
+			t.Fatalf("expected GET method, got: %s", r.Method)
+		}
 		marketplaceID := r.Header.Get("X-EBAY-C-MARKETPLACE-ID")
 		fmt.Fprintf(w, `{"itemId": "%s"}`, marketplaceID)
 	})
@@ -29,3 +34,32 @@ func TestGetBidding(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, ebay.BuyMarketplaceUSA, bidding.ItemID)
 }
+
+func TestPlaceProxyBid(t *testing.T) {
+	client, mux, teardown := setup(t)
+	defer teardown()
+
+	mux.HandleFunc("/buy/offer/v1_beta/bidding/v1|202117468662|0/place_proxy_bid", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "POST" {
+			t.Fatalf("expected POST method, got: %s", r.Method)
+		}
+		marketplaceID := r.Header.Get("X-EBAY-C-MARKETPLACE-ID")
+		body, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			t.Fatalf("%+v", err)
+			http.Error(w, err.Error(), 500)
+			return
+		}
+		escapedBody := strconv.Quote(string(body))
+		escapedBody = escapedBody[1 : len(escapedBody)-1]
+		fmt.Fprintf(w, `{"proxyBidId": "%s_%s"}`, escapedBody, marketplaceID)
+	})
+
+	bid, err := client.Buy.Offer.PlaceProxyBid(context.Background(), "v1|202117468662|0", ebay.BuyMarketplaceUSA, "1.23", "USD", false)
+	assert.Nil(t, err)
+	assert.Equal(t, "{\"maxAmount\":{\"currency\":\"USD\",\"value\":\"1.23\"}}\n_EBAY_US", bid.ProxyBidID)
+
+	bid, err = client.Buy.Offer.PlaceProxyBid(context.Background(), "v1|202117468662|0", ebay.BuyMarketplaceUSA, "1.23", "USD", true)
+	assert.Nil(t, err)
+	assert.Equal(t, "{\"maxAmount\":{\"currency\":\"USD\",\"value\":\"1.23\"},\"userConsent\":{\"adultOnlyItem\":true}}\n_EBAY_US", bid.ProxyBidID)
+}
diff --git a/test/integration/auction_test.go b/test/integration/auction_test.go
index fe7f6ae..48a754c 100644
--- a/test/integration/auction_test.go
+++ b/test/integration/auction_test.go
@@ -9,21 +9,22 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
 
 	_ "github.com/joho/godotenv/autoload"
 	"github.com/jybp/ebay"
-	"github.com/jybp/ebay/tokensource"
 	"golang.org/x/oauth2"
-	oclientcredentials "golang.org/x/oauth2/clientcredentials"
+	"golang.org/x/oauth2/clientcredentials"
 )
 
 var (
 	integration  bool
 	clientID     string
 	clientSecret string
+	auctionURL   string
 )
 
 func init() {
@@ -34,8 +35,10 @@ func init() {
 	}
 	clientID = os.Getenv("SANDBOX_CLIENT_ID")
 	clientSecret = os.Getenv("SANDBOX_CLIENT_SECRET")
-	if clientID == "" || clientSecret == "" {
-		panic("No SANDBOX_CLIENT_ID or SANDBOX_CLIENT_SECRET. Tests won't run.")
+	// You have to manually create an auction in the sandbox. Auctions can't be created using the rest api (yet?).
+	auctionURL = os.Getenv("SANDOX_AUCTION_URL")
+	if clientID == "" || clientSecret == "" || auctionURL == "" {
+		panic("Please set SANDBOX_CLIENT_ID, SANDBOX_CLIENT_SECRET and SANDOX_AUCTION_URL.")
 	}
 }
 
@@ -44,20 +47,16 @@ func TestAuction(t *testing.T) {
 		t.SkipNow()
 	}
 
-	// Manually create an auction in the sandbox and copy/paste the url.
-	// Auctions can't be created using the rest api (yet?).
-	const auctionURL = "https://www.sandbox.ebay.com/itm/110440008951"
-
 	ctx := context.Background()
 
-	conf := oclientcredentials.Config{
+	conf := clientcredentials.Config{
 		ClientID:     clientID,
 		ClientSecret: clientSecret,
 		TokenURL:     "https://api.sandbox.ebay.com/identity/v1/oauth2/token",
 		Scopes:       []string{"https://api.ebay.com/oauth/api_scope"},
 	}
 
-	client := ebay.NewSandboxClient(oauth2.NewClient(ctx, tokensource.New(conf.TokenSource(ctx))))
+	client := ebay.NewSandboxClient(oauth2.NewClient(ctx, ebay.TokenSource(conf.TokenSource(ctx))))
 
 	lit, err := client.Buy.Browse.GetItemByLegacyID(ctx, auctionURL[strings.LastIndex(auctionURL, "/")+1:])
 	if err != nil {
@@ -84,8 +83,6 @@ func TestAuction(t *testing.T) {
 	}
 	t.Logf("item %s UniqueBidderCount:%d minimumBidPrice: %+v currentPriceToBid: %+v\n", it.ItemID, it.UniqueBidderCount, it.MinimumPriceToBid, it.CurrentBidPrice)
 
-	// Setup oauth server.
-
 	b := make([]byte, 16)
 	if _, err := io.ReadFull(rand.Reader, b); err != nil {
 		t.Fatalf("%+v", err)
@@ -139,13 +136,32 @@ func TestAuction(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	client = ebay.NewSandboxClient(oauth2.NewClient(ctx, tokensource.New(oauthConf.TokenSource(ctx, tok))))
+	client = ebay.NewSandboxClient(oauth2.NewClient(ctx, ebay.TokenSource(oauthConf.TokenSource(ctx, tok))))
 
-	_, err = client.Buy.Offer.GetBidding(ctx, it.ItemID, ebay.BuyMarketplaceUSA)
-	if !ebay.IsError(err, ebay.ErrGetBiddingNoBiddingActivity) {
-		t.Logf("Expected ErrNoBiddingActivity, got %+v.", err)
+	bid, err := client.Buy.Offer.GetBidding(ctx, it.ItemID, ebay.BuyMarketplaceUSA)
+	if err != nil && !ebay.IsError(err, ebay.ErrGetBiddingNoBiddingActivity) {
+		t.Fatalf("Expected error code %d, got %+v.", ebay.ErrGetBiddingNoBiddingActivity, err)
 	}
 
-	// err := client.Buy.Offer.PlaceProxyBid(ctx)
+	var bidValue, bidCurrency string
+	if len(bid.SuggestedBidAmounts) > 0 {
+		bidValue = bid.SuggestedBidAmounts[0].Value
+		bidCurrency = bid.SuggestedBidAmounts[0].Currency
+	} else {
+		bidValue = it.CurrentBidPrice.Value
+		v, err := strconv.ParseFloat(bidValue, 64)
+		if err != nil {
+			t.Fatal(err)
+		}
+		v += 2
+		bidValue = fmt.Sprintf("%.2f", v)
+		bidCurrency = it.CurrentBidPrice.Currency
+	}
 
+	_, err = client.Buy.Offer.PlaceProxyBid(ctx, it.ItemID, ebay.BuyMarketplaceUSA, bidValue, bidCurrency, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("Successfully bid %+v.", bid.SuggestedBidAmounts[0])
 }
diff --git a/tokensource/tokensource.go b/tokensource/tokensource.go
deleted file mode 100644
index 8bc0291..0000000
--- a/tokensource/tokensource.go
+++ /dev/null
@@ -1,26 +0,0 @@
-package tokensource
-
-import "golang.org/x/oauth2"
-
-// type TokenSource interface {
-// 	// Token returns a token or an error.
-// 	// Token must be safe for concurrent use by multiple goroutines.
-// 	// The returned Token must not be modified.
-// 	Token() (*Token, error)
-// }
-
-type TokenSource struct {
-	base oauth2.TokenSource
-}
-
-func New(base oauth2.TokenSource) *TokenSource {
-	return &TokenSource{base: base}
-}
-
-func (ts *TokenSource) Token() (*oauth2.Token, error) {
-	t, err := ts.base.Token()
-	if t != nil {
-		t.TokenType = "Bearer"
-	}
-	return t, err
-}

From 1af95b0307dd62515f67608c22742a02d875b854 Mon Sep 17 00:00:00 2001
From: JBP <2850825+jybp@users.noreply.github.com>
Date: Sat, 17 Aug 2019 18:20:55 +0200
Subject: [PATCH 4/4] setup tls

---
 ebay.go                          |  9 ++--
 test/integration/auction_test.go | 22 ++++----
 test/integration/tls.go          | 87 ++++++++++++++++++++++++++++++++
 3 files changed, 99 insertions(+), 19 deletions(-)
 create mode 100644 test/integration/tls.go

diff --git a/ebay.go b/ebay.go
index 440cc2e..7c5e383 100644
--- a/ebay.go
+++ b/ebay.go
@@ -88,20 +88,17 @@ func (c *Client) NewRequest(method, url string, body interface{}, opts ...Opt) (
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
-	var bodyR io.Reader
+	var buf io.ReadWriter
 	if body != nil {
-		buf := new(bytes.Buffer)
+		buf = new(bytes.Buffer)
 		enc := json.NewEncoder(buf)
 		enc.SetEscapeHTML(false)
 		if err := enc.Encode(body); err != nil {
 			return nil, err
 		}
-		b := buf.Bytes()
-		print("body:" + string(b)) // TODO
-		bodyR = bytes.NewReader(b)
 	}
 
-	req, err := http.NewRequest(method, u.String(), bodyR)
+	req, err := http.NewRequest(method, u.String(), buf)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
diff --git a/test/integration/auction_test.go b/test/integration/auction_test.go
index 48a754c..c50eec5 100644
--- a/test/integration/auction_test.go
+++ b/test/integration/auction_test.go
@@ -35,10 +35,8 @@ func init() {
 	}
 	clientID = os.Getenv("SANDBOX_CLIENT_ID")
 	clientSecret = os.Getenv("SANDBOX_CLIENT_SECRET")
-	// You have to manually create an auction in the sandbox. Auctions can't be created using the rest api (yet?).
-	auctionURL = os.Getenv("SANDOX_AUCTION_URL")
-	if clientID == "" || clientSecret == "" || auctionURL == "" {
-		panic("Please set SANDBOX_CLIENT_ID, SANDBOX_CLIENT_SECRET and SANDOX_AUCTION_URL.")
+	if clientID == "" || clientSecret == "" {
+		panic("Please set SANDBOX_CLIENT_ID and SANDBOX_CLIENT_SECRET.")
 	}
 }
 
@@ -49,6 +47,9 @@ func TestAuction(t *testing.T) {
 
 	ctx := context.Background()
 
+	// You have to manually create an auction in the sandbox. Auctions can't be created using the rest api (yet?).
+	auctionURL = os.Getenv("SANDOX_AUCTION_URL")
+
 	conf := clientcredentials.Config{
 		ClientID:     clientID,
 		ClientSecret: clientSecret,
@@ -66,9 +67,6 @@ func TestAuction(t *testing.T) {
 	if err != nil {
 		t.Fatalf("%+v", err)
 	}
-	if testing.Verbose() {
-		t.Logf("item: %+v\n", it)
-	}
 	isAuction := false
 	for _, opt := range it.BuyingOptions {
 		if opt == ebay.BrowseBuyingOptionAuction {
@@ -89,7 +87,8 @@ func TestAuction(t *testing.T) {
 	}
 	state := url.QueryEscape(string(b))
 	authCodeC := make(chan string)
-	http.HandleFunc("/accept", func(rw http.ResponseWriter, r *http.Request) {
+	mux := setupTLS()
+	mux.HandleFunc("/accept", func(rw http.ResponseWriter, r *http.Request) {
 		actualState, err := url.QueryUnescape(r.URL.Query().Get("state"))
 		if err != nil {
 			http.Error(rw, fmt.Sprintf("invalid state: %+v", err), http.StatusBadRequest)
@@ -105,15 +104,12 @@ func TestAuction(t *testing.T) {
 		t.Logf("The authorization code will expire in %s seconds.\n", r.URL.Query().Get("expires_in"))
 		rw.Write([]byte("Accept. You can safely close this tab."))
 	})
-	http.HandleFunc("/policy", func(rw http.ResponseWriter, r *http.Request) {
+	mux.HandleFunc("/policy", func(rw http.ResponseWriter, r *http.Request) {
 		rw.Write([]byte("eBay Sniper Policy"))
 	})
-	http.HandleFunc("/decline", func(rw http.ResponseWriter, r *http.Request) {
+	mux.HandleFunc("/decline", func(rw http.ResponseWriter, r *http.Request) {
 		rw.Write([]byte("Decline. You can safely close this tab."))
 	})
-	go func() {
-		t.Fatal(http.ListenAndServe(":52125", nil))
-	}()
 
 	oauthConf := oauth2.Config{
 		ClientID:     clientID,
diff --git a/test/integration/tls.go b/test/integration/tls.go
new file mode 100644
index 0000000..e9c1f6a
--- /dev/null
+++ b/test/integration/tls.go
@@ -0,0 +1,87 @@
+package integration
+
+// From https://gist.github.com/shivakar/cd52b5594d4912fbeb46
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"log"
+	"math/big"
+	"net"
+	"net/http"
+	"time"
+)
+
+// From https://golang.org/src/net/http/server.go
+// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
+// connections. It's used by ListenAndServe and ListenAndServeTLS so
+// dead TCP connections (e.g. closing laptop mid-download) eventually
+// go away.
+type tcpKeepAliveListener struct {
+	*net.TCPListener
+	keepAlivePeriod time.Duration
+}
+
+func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
+	tc, err := ln.AcceptTCP()
+	if err != nil {
+		return
+	}
+	tc.SetKeepAlive(true)
+	tc.SetKeepAlivePeriod(ln.keepAlivePeriod)
+	return tc, nil
+}
+
+func tlsCert(name string, dur time.Duration) (tls.Certificate, error) {
+	now := time.Now()
+	template := &x509.Certificate{
+		SerialNumber:          big.NewInt(0),
+		Subject:               pkix.Name{CommonName: name},
+		NotBefore:             now,
+		NotAfter:              now.Add(dur),
+		BasicConstraintsValid: true,
+		IsCA:                  true,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+	}
+
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return tls.Certificate{}, err
+	}
+
+	cert, err := x509.CreateCertificate(rand.Reader, template, template, priv.Public(), priv)
+	if err != nil {
+		return tls.Certificate{}, err
+	}
+
+	var outCert tls.Certificate
+	outCert.Certificate = append(outCert.Certificate, cert)
+	outCert.PrivateKey = priv
+	return outCert, nil
+}
+
+func setupTLS() *http.ServeMux {
+	cert, err := tlsCert("eSniper", time.Hour)
+	if err != nil {
+		log.Fatal(err)
+	}
+	mux := http.NewServeMux()
+	srv := &http.Server{Addr: ":52125", Handler: mux}
+	cfg := &tls.Config{}
+	cfg.NextProtos = []string{"http/1.1"}
+	cfg.Certificates = make([]tls.Certificate, 1)
+	cfg.Certificates[0] = cert
+	ln, err := net.Listen("tcp", ":52125")
+	if err != nil {
+		log.Fatal(err)
+	}
+	tlsListener := tls.NewListener(tcpKeepAliveListener{ln.(*net.TCPListener), time.Minute}, cfg)
+	go func() {
+		srv.Serve(tlsListener)
+	}()
+	return mux
+}