Support reply-after for 429 & 503 responses (#26)

* Forward Reply-After header in Response

* Test retry-after and x-debug-id header parsing

* in-passing dependency update

go.mod

@@ -12,4 +12,4 @@ module github.com/adobe/ims-go
 
 go 1.18
 
-require github.com/golang-jwt/jwt/v5 v5.0.0
+require github.com/golang-jwt/jwt/v5 v5.2.1

go.sum

@@ -1,2 +1,4 @@
 github.com/golang-jwt/jwt/v5 v5.0.0 h1:1n1XNM9hk7O9mnQoNBGolZvzebBQ7p93ULHRc28XJUE=
 github.com/golang-jwt/jwt/v5 v5.0.0/go.mod h1:pqrtFR0X4osieyHYxtmOUWsAWrfe1Q5UVIyoH402zdk=
+github.com/golang-jwt/jwt/v5 v5.2.1 h1:OuVbFODueb089Lh128TAcimifWaLhJwVflnrgM17wHk=
+github.com/golang-jwt/jwt/v5 v5.2.1/go.mod h1:pqrtFR0X4osieyHYxtmOUWsAWrfe1Q5UVIyoH402zdk=

ims/client.go

@@ -76,7 +76,8 @@ type Response struct {
 	// The raw body of the HTTP response.
 	Body []byte
 	// The value of the X-Debug-Id header.
-	XDebugID string
+	XDebugID   string
+	RetryAfter string
 }
 
 func (c *Client) do(req *http.Request) (*Response, error) {
@@ -93,10 +94,12 @@ func (c *Client) do(req *http.Request) (*Response, error) {
 
 	// X-Debug-Id is the header used by IMS to track requests.
 	xdebugid := res.Header.Get("x-debug-id")
+	retryAfter := res.Header.Get("Retry-After")
 
 	return &Response{
 		StatusCode: res.StatusCode,
 		Body:       data,
 		XDebugID:   xdebugid,
+		RetryAfter: retryAfter,
 	}, nil
 }

ims/cluster_exchange_token_test.go

@@ -141,6 +141,66 @@ func TestClusterExchangeError(t *testing.T) {
 	}
 }
 
+func TestClusterExchangeTooManyRequests(t *testing.T) {
+	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Retry-After", "77")
+		w.Header().Set("x-debug-id", "banana")
+		w.WriteHeader(http.StatusTooManyRequests)
+
+		body := struct {
+			ErrorCode    string `json:"error"`
+			ErrorMessage string `json:"error_description"`
+		}{
+			ErrorCode:    "error-code",
+			ErrorMessage: "error-message",
+		}
+
+		if err := json.NewEncoder(w).Encode(&body); err != nil {
+			t.Fatalf("encode response: %v", err)
+		}
+	}))
+	defer s.Close()
+
+	c, err := ims.NewClient(&ims.ClientConfig{
+		URL: s.URL,
+	})
+	if err != nil {
+		t.Fatalf("create client: %v", err)
+	}
+
+	res, err := c.ClusterExchange(&ims.ClusterExchangeRequest{
+		ClientID:     "irrelevant",
+		ClientSecret: "irrelevant",
+		Scopes:       []string{"yolo", "test"},
+		UserToken:    "old-token",
+		OrgID:        "orgid",
+	})
+
+	if res != nil {
+		t.Fatalf("expected nil response because of error")
+	}
+
+	imsErr, ok := ims.IsError(err)
+	if !ok {
+		t.Fatalf("expected IMS error")
+	}
+	if imsErr.StatusCode != http.StatusTooManyRequests {
+		t.Fatalf("invalid status code: %v", imsErr.StatusCode)
+	}
+	if imsErr.ErrorCode != "error-code" {
+		t.Fatalf("invalid error code: %v", imsErr.ErrorCode)
+	}
+	if imsErr.ErrorMessage != "error-message" {
+		t.Fatalf("invalid error message: %v", imsErr.ErrorMessage)
+	}
+	if imsErr.RetryAfter != "77" {
+		t.Fatalf("invalid retry-after header: %v", imsErr.RetryAfter)
+	}
+	if imsErr.XDebugID != "banana" {
+		t.Fatalf("invalid x-debug-id header: %v", imsErr.RetryAfter)
+	}
+}
+
 func TestClusterExchangeInvalidRequest(t *testing.T) {
 	c, err := ims.NewClient(&ims.ClientConfig{
 		URL: "http://ims.endpoint",

ims/error.go

@@ -26,6 +26,16 @@ type Error struct {
 }
 
 func (e *Error) Error() string {
+	if e.RetryAfter != "" {
+		return fmt.Sprintf(
+			"error response: statusCode=%d, errorCode='%s', errorMessage='%s', x-debug-id='%s', retry-after='%s'",
+			e.StatusCode,
+			e.ErrorCode,
+			e.ErrorMessage,
+			e.XDebugID,
+			e.RetryAfter,
+		)
+	}
 	return fmt.Sprintf(
 		"error response: statusCode=%d, errorCode='%s', errorMessage='%s', x-debug-id='%s'",
 		e.StatusCode,

ims/get_profile_test.go

@@ -75,3 +75,56 @@ func TestGetProfileEmptyErrorResponse(t *testing.T) {
 		t.Fatalf("invalid error type: %v", err)
 	}
 }
+
+func TestGetProfileTooManyRequests(t *testing.T) {
+	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			t.Fatalf("invalid method: %v", r.Method)
+		}
+		if v := r.Header.Get("authorization"); v != "Bearer accessToken" {
+			t.Fatalf("invalid authorization header: %v", v)
+		}
+
+		w.Header().Set("Retry-After", "77")
+		w.Header().Set("x-debug-id", "banana")
+		w.WriteHeader(http.StatusTooManyRequests)
+	}))
+	defer s.Close()
+
+	c, err := ims.NewClient(&ims.ClientConfig{
+		URL: s.URL,
+	})
+	if err != nil {
+		t.Fatalf("create client: %v", err)
+	}
+
+	res, err := c.GetProfile(&ims.GetProfileRequest{
+		AccessToken: "accessToken",
+	})
+
+	if err == nil {
+		t.Fatalf("expected error in get profile")
+	}
+
+	if res != nil {
+		t.Fatalf("expected nil response because of error")
+	}
+
+	imsErr, ok := ims.IsError(err)
+	if !ok {
+		t.Fatalf("expected IMS error")
+	}
+
+	if imsErr.StatusCode != http.StatusTooManyRequests {
+		t.Fatalf("invalid status code: %v", imsErr.StatusCode)
+	}
+
+	if imsErr.RetryAfter != "77" {
+		t.Fatalf("invalid retry-after header: %v", imsErr.RetryAfter)
+	}
+
+	if imsErr.XDebugID != "banana" {
+		t.Fatalf("invalid x-debug-id header: %v", imsErr.XDebugID)
+	}
+
+}