feat: added validation method for pagination cache

Author: Aerex

bluemix/configuration/config_helpers/helpers.go

@@ -2,6 +2,8 @@
 package config_helpers
 
 import (
+	"encoding/base64"
+	gourl "net/url"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -91,3 +93,45 @@ func UserHomeDir() string {
 
 	return os.Getenv("HOME")
 }
+
+// IsValidPaginationNextURL will return true if the provided nextURL has the expected queries provided
+func IsValidPaginationNextURL(nextURL string, cursorQueryParamName string, expectedQueries gourl.Values) bool {
+	parsedURL, parseErr := gourl.Parse(nextURL)
+	// NOTE: ignore handling error(s) since if there error(s)
+	// we can assume the url is invalid
+	if parseErr != nil {
+		return false
+	}
+
+	// retrive encoded cursor
+	// eg. /api?cursor=<encode_string>
+	queries := parsedURL.Query()
+	encodedQuery := queries.Get(cursorQueryParamName)
+	if encodedQuery == "" {
+		return false
+
+	}
+	// decode string and parse encoded queries
+	decodedQuery, decodedErr := base64.RawURLEncoding.DecodeString(encodedQuery)
+	if decodedErr != nil {
+		return false
+	}
+	queries, parsedErr := gourl.ParseQuery(string(decodedQuery))
+	if parsedErr != nil {
+		return false
+	}
+
+	// compare expected queries that should match
+	// NOTE: assume queries are single value queries.
+	// if multi-value queries will check the first query
+	for expectedQuery := range expectedQueries {
+		paginationQueryValue := queries.Get(expectedQuery)
+		expectedQueryValue := expectedQueries.Get(expectedQuery)
+		if paginationQueryValue != expectedQueryValue {
+			return false
+		}
+
+	}
+
+	return true
+}

bluemix/configuration/config_helpers/helpers_test.go

@@ -1,7 +1,9 @@
 package config_helpers
 
 import (
+	"encoding/base64"
 	"io/ioutil"
+	gourl "net/url"
 	"os"
 	"path/filepath"
 	"strings"
@@ -103,3 +105,62 @@ func TestConfigDir_IbmCloudConfigHomeSet_Exists(t *testing.T) {
 	os.Setenv("IBMCLOUD_CONFIG_HOME", userHome)
 	assert.Equal(userHome, ConfigDir())
 }
+
+func TestIsValidPaginationNextURL(t *testing.T) {
+	assert := assert.New(t)
+
+	testCases := []struct {
+		name              string
+		nextURL           string
+		encodedQueryParam string
+		expectedQueries   gourl.Values
+		isValid           bool
+	}{
+		{
+			name:              "return true for matching expected queries in pagination url",
+			nextURL:           "/api/example?cursor=" + base64.RawURLEncoding.EncodeToString([]byte("limit=100&active=true")),
+			encodedQueryParam: "cursor",
+			expectedQueries: gourl.Values{
+				"limit":  []string{"100"},
+				"active": []string{"true"},
+			},
+			isValid: true,
+		},
+		{
+			name:              "return true for matching expected queries with extraneous queries in pagination url",
+			nextURL:           "/api/example?cursor=" + base64.RawURLEncoding.EncodeToString([]byte("limit=100&active=true&extra=foo")),
+			encodedQueryParam: "cursor",
+			expectedQueries: gourl.Values{
+				"limit":  []string{"100"},
+				"active": []string{"true"},
+			},
+			isValid: true,
+		},
+		{
+			name:              "return false for different limit in pagination url",
+			nextURL:           "/api/example?cursor=" + base64.RawURLEncoding.EncodeToString([]byte("limit=200")),
+			encodedQueryParam: "cursor",
+			expectedQueries: gourl.Values{
+				"limit": []string{"100"},
+			},
+			isValid: false,
+		},
+		{
+			name:              "return false for different query among multiple parameters in the pagination url",
+			nextURL:           "/api/example?cursor=" + base64.RawURLEncoding.EncodeToString([]byte("limit=100&active=true")),
+			encodedQueryParam: "cursor",
+			expectedQueries: gourl.Values{
+				"limit":  []string{"100"},
+				"active": []string{"false"},
+			},
+			isValid: false,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(_ *testing.T) {
+			isValid := IsValidPaginationNextURL(tc.nextURL, tc.encodedQueryParam, tc.expectedQueries)
+			assert.Equal(tc.isValid, isValid)
+		})
+	}
+}

common/rest/request_test.go

@@ -137,11 +137,13 @@ func TestCachedPaginationNextURL(t *testing.T) {
 		name            string
 		paginationURLs  []models.PaginationURL
 		offset          int
+		limit           int
 		expectedNextURL string
 	}{
 		{
 			name:   "return cached next URL",
 			offset: 200,
+			limit:  100,
 			paginationURLs: []models.PaginationURL{
 				{
 					NextURL:   "/v2/example.com/stuff?limit=100",
@@ -153,6 +155,7 @@ func TestCachedPaginationNextURL(t *testing.T) {
 		{
 			name:   "return empty string if cache URL cannot be determined",
 			offset: 40,
+			limit:  100,
 			paginationURLs: []models.PaginationURL{
 				{
 					NextURL:   "/v2/example.com/stuff?limit=100",
@@ -164,9 +167,22 @@ func TestCachedPaginationNextURL(t *testing.T) {
 		{
 			name:            "return empty string if no cache available",
 			offset:          40,
+			limit:           100,
 			paginationURLs:  []models.PaginationURL{},
 			expectedNextURL: "",
 		},
+		{
+			name:   "return empty string if limit in url is different than provided limit",
+			offset: 200,
+			limit:  200,
+			paginationURLs: []models.PaginationURL{
+				{
+					NextURL:   "/v2/example.com?stuff?limit=100",
+					LastIndex: 100,
+				},
+			},
+			expectedNextURL: "",
+		},
 	}
 
 	assert := assert.New(t)