fix: migrate flag listing to REST API 20240415 with pagination

CHANGELOG.md

@@ -8,6 +8,10 @@
 
 ### Fixed
 
+- Update flag listing from deprecated REST API version `20220603` to the current version,
+  [`20240415`](https://launchdarkly.com/docs/guides/api/api-migration-guide), including pagination support
+  for active and archived flags
+
 ## 2.3.0
 
 ### Added

internal/ldclient/flags.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"strconv"
 
 	ldapi "github.com/launchdarkly/api-client-go/v15"
 	lcr "github.com/launchdarkly/find-code-references-in-pull-request/config"
@@ -39,15 +40,38 @@ func GetAllFlags(config *lcr.Config) ([]ldapi.FeatureFlag, error) {
 }
 
 func getFlags(config *lcr.Config, params url.Values) ([]ldapi.FeatureFlag, error) {
-	url := fmt.Sprintf("%s/api/v2/flags/%s", config.LdInstance, config.LdProject)
+	pageParams := make(url.Values, len(params)+2)
+	for key, values := range params {
+		pageParams[key] = append([]string(nil), values...)
+	}
+	const pageSize = 100
+	pageParams.Set("limit", strconv.Itoa(pageSize))
+
 	client := &http.Client{}
+	flags := []ldapi.FeatureFlag{}
+	for offset := 0; ; offset += pageSize {
+		pageParams.Set("offset", strconv.Itoa(offset))
+		page, err := getFlagPage(client, config, pageParams)
+		if err != nil {
+			return []ldapi.FeatureFlag{}, err
+		}
+		// The migration guide uses an empty page to signal completion.
+		if len(page) == 0 {
+			return flags, nil
+		}
+		flags = append(flags, page...)
+	}
+}
+
+func getFlagPage(client *http.Client, config *lcr.Config, params url.Values) ([]ldapi.FeatureFlag, error) {
+	url := fmt.Sprintf("%s/api/v2/flags/%s", config.LdInstance, config.LdProject)
 	req, err := http.NewRequest(http.MethodGet, url, nil)
 	if err != nil {
 		return []ldapi.FeatureFlag{}, err
 	}
 	req.URL.RawQuery = params.Encode()
 	req.Header.Add("Authorization", config.ApiToken)
-	req.Header.Add("LD-API-Version", "20220603")
+	req.Header.Add("LD-API-Version", "20240415")
 	req.Header.Add("User-Agent", fmt.Sprintf("find-code-references-pr/%s", version.Version))
 
 	resp, err := client.Do(req)

internal/ldclient/flags_test.go

@@ -0,0 +1,237 @@
+package ldapi
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strconv"
+	"sync/atomic"
+	"testing"
+
+	ldapi "github.com/launchdarkly/api-client-go/v15"
+	lcr "github.com/launchdarkly/find-code-references-in-pull-request/config"
+	"github.com/launchdarkly/find-code-references-in-pull-request/internal/version"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetAllFlagsPagination(t *testing.T) {
+	tests := []struct {
+		name          string
+		activePages   []int
+		archivedPages []int
+	}{
+		{name: "empty", activePages: []int{0}},
+		{name: "one flag", activePages: []int{1, 0}},
+		{name: "exactly one full page", activePages: []int{100, 0}},
+		{name: "multiple active pages", activePages: []int{100, 1, 0}},
+		{name: "multiple active and archived pages", activePages: []int{100, 1, 0}, archivedPages: []int{100, 2, 0}},
+		{name: "empty active collection", activePages: []int{0}, archivedPages: []int{2, 0}},
+		{name: "empty archived collection", activePages: []int{1, 0}, archivedPages: []int{0}},
+		{name: "short pages", activePages: []int{2, 1, 0}, archivedPages: []int{1, 0}},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var pages []flagPageResponse
+			wantKeys := []string{}
+			for collection, sizes := range [][]int{tt.activePages, tt.archivedPages} {
+				filter, prefix := "", "active"
+				if collection == 1 {
+					filter, prefix = "state:archived", "archived"
+				}
+				keyOffset := 0
+				requestOffset := 0
+				for _, count := range sizes {
+					items := make([]map[string]string, count)
+					for i := range items {
+						key := fmt.Sprintf("%s-%d", prefix, keyOffset+i)
+						items[i] = map[string]string{"key": key}
+						wantKeys = append(wantKeys, key)
+					}
+					body, err := json.Marshal(map[string]any{"items": items})
+					require.NoError(t, err)
+					pages = append(pages, flagPageResponse{offset: requestOffset, filter: filter, body: string(body)})
+					keyOffset += count
+					requestOffset += 100
+				}
+			}
+			config := serveFlagPages(t, tt.archivedPages != nil, pages)
+
+			flags, err := GetAllFlags(config)
+
+			require.NoError(t, err)
+			gotKeys := make([]string, len(flags))
+			for i, flag := range flags {
+				gotKeys[i] = flag.Key
+			}
+			assert.Equal(t, wantKeys, gotKeys)
+		})
+	}
+}
+
+func TestGetAllFlagsPreservesMetadata(t *testing.T) {
+	config := serveFlagPages(t, false, []flagPageResponse{
+		{body: `{"items":[{"key":"checkout","name":"Checkout","kind":"boolean","tags":["billing"],
+			"environments":{"production":{"on":true,"_environmentName":"Production",
+			"_site":{"href":"/test-project/production/features/checkout","type":"text/html"}}}}]}`},
+		{offset: 100, body: `{"items":[]}`},
+	})
+
+	flags, err := GetAllFlags(config)
+
+	require.NoError(t, err)
+	require.Len(t, flags, 1)
+	assert.Equal(t, ldapi.FeatureFlag{
+		Key:  "checkout",
+		Name: "Checkout",
+		Kind: "boolean",
+		Tags: []string{"billing"},
+		Environments: map[string]ldapi.FeatureFlagConfig{
+			"production": {
+				On:              true,
+				EnvironmentName: "Production",
+				Site: ldapi.Link{
+					Href: ldapi.PtrString("/test-project/production/features/checkout"),
+					Type: ldapi.PtrString("text/html"),
+				},
+			},
+		},
+	}, flags[0])
+}
+
+func TestGetFlagsPreservesQueryParameters(t *testing.T) {
+	config := serveFlagPages(t, true, []flagPageResponse{
+		{filter: "state:archived", body: `{"items":[{"key":"archived"}]}`},
+		{offset: 100, filter: "state:archived", body: `{"items":[]}`},
+	})
+	params := url.Values{
+		"env":    {"production"},
+		"filter": {"state:archived"},
+		"limit":  {"20"},
+		"offset": {"42"},
+	}
+	want := url.Values{
+		"env":    {"production"},
+		"filter": {"state:archived"},
+		"limit":  {"20"},
+		"offset": {"42"},
+	}
+
+	flags, err := getFlags(config, params)
+
+	require.NoError(t, err)
+	assert.Len(t, flags, 1)
+	assert.Equal(t, want, params)
+}
+
+func TestGetAllFlagsErrors(t *testing.T) {
+	tests := []struct {
+		name      string
+		status    int
+		body      string
+		wantError string
+	}{
+		{
+			name: "unauthorized", status: http.StatusUnauthorized,
+			body: `{"message":"unauthorized"}`, wantError: "401",
+		},
+		{
+			name: "server error", status: http.StatusInternalServerError,
+			body: `{"message":"unavailable"}`, wantError: "500",
+		},
+		{
+			name: "non-JSON error", status: http.StatusBadGateway,
+			body: "bad gateway", wantError: "502. unable to parse response",
+		},
+		{
+			name: "invalid success JSON", status: http.StatusOK,
+			body: "not JSON", wantError: "invalid character",
+		},
+	}
+	for _, tt := range tests {
+		for _, archived := range []bool{false, true} {
+			for _, laterPage := range []bool{false, true} {
+				name := fmt.Sprintf("%s/archived=%t/laterPage=%t", tt.name, archived, laterPage)
+				t.Run(name, func(t *testing.T) {
+					var pages []flagPageResponse
+					filter := ""
+					if archived {
+						pages = append(pages,
+							flagPageResponse{body: `{"items":[{"key":"active"}]}`},
+							flagPageResponse{offset: 100, body: `{"items":[]}`},
+						)
+						filter = "state:archived"
+					}
+					offset := 0
+					if laterPage {
+						pages = append(pages, flagPageResponse{filter: filter, body: `{"items":[{"key":"first"}]}`})
+						offset = 100
+					}
+					pages = append(pages, flagPageResponse{offset: offset, filter: filter, status: tt.status, body: tt.body})
+					config := serveFlagPages(t, archived, pages)
+
+					flags, err := GetAllFlags(config)
+
+					require.ErrorContains(t, err, tt.wantError)
+					assert.Empty(t, flags)
+				})
+			}
+		}
+	}
+}
+
+type flagPageResponse struct {
+	offset int
+	filter string
+	status int
+	body   string
+}
+
+func serveFlagPages(t *testing.T, includeArchived bool, pages []flagPageResponse) *lcr.Config {
+	t.Helper()
+	var requests atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		index := int(requests.Add(1)) - 1
+		if !assert.Less(t, index, len(pages), "unexpected flag-list request") {
+			http.Error(w, "unexpected flag-list request", http.StatusInternalServerError)
+			return
+		}
+		page := pages[index]
+		assert.Equal(t, http.MethodGet, r.Method)
+		assert.Equal(t, "/api/v2/flags/test-project", r.URL.Path)
+		assert.Equal(t, "test-api-token", r.Header.Get("Authorization"))
+		assert.Equal(t, "20240415", r.Header.Get("LD-API-Version"))
+		assert.Equal(t, "find-code-references-pr/"+version.Version, r.Header.Get("User-Agent"))
+		query := url.Values{
+			"env":    {"production"},
+			"limit":  {"100"},
+			"offset": {strconv.Itoa(page.offset)},
+		}
+		if page.filter != "" {
+			query.Set("filter", page.filter)
+		}
+		assert.Equal(t, query, r.URL.Query())
+		w.Header().Set("Content-Type", "application/json")
+		status := page.status
+		if status == 0 {
+			status = http.StatusOK
+		}
+		w.WriteHeader(status)
+		_, err := w.Write([]byte(page.body))
+		assert.NoError(t, err)
+	}))
+	t.Cleanup(func() {
+		server.Close()
+		assert.Equal(t, len(pages), int(requests.Load()), "flag-list request count")
+	})
+	return &lcr.Config{
+		LdInstance:           server.URL,
+		LdProject:            "test-project",
+		LdEnvironment:        "production",
+		ApiToken:             "test-api-token",
+		IncludeArchivedFlags: includeArchived,
+	}
+}