fix(chat): fetch public keys per user

api/chat.go

@@ -91,30 +91,22 @@ func GetChatPublicKeys(client Client, userID string, opts RequestOptions) ([]Cha
 }
 
 // GetChatUsersPublicKeys fetches registered public keys for the given users;
-// each returned row carries its owner's user_id. The endpoint accepts at
-// most 100 ids per request, so larger inputs are fetched in batches.
+// each returned row carries its owner's user_id. Public keys are fetched via
+// the per-user route because the batch route is not enabled for every X app.
 func GetChatUsersPublicKeys(client Client, userIDs []string, opts RequestOptions) ([]ChatPublicKey, error) {
 	if len(userIDs) == 0 {
 		return nil, nil
 	}
 	var keys []ChatPublicKey
-	for start := 0; start < len(userIDs); start += 100 {
-		batch := userIDs[start:min(start+100, len(userIDs))]
-		opts.Method = "GET"
-		opts.Endpoint = "/2/users/public_keys?ids=" + url.QueryEscape(strings.Join(batch, ","))
-		opts.Data = ""
-
-		resp, err := client.SendRequest(opts)
+	for _, userID := range userIDs {
+		userKeys, err := GetChatPublicKeys(client, userID, opts)
 		if err != nil {
-			return nil, err
-		}
-		var out struct {
-			Data []ChatPublicKey `json:"data"`
+			return nil, fmt.Errorf("failed to fetch public keys for user %s: %w", userID, err)
 		}
-		if err := json.Unmarshal(resp, &out); err != nil {
-			return nil, fmt.Errorf("failed to parse public keys response: %w", err)
+		for i := range userKeys {
+			userKeys[i].UserID = userID
 		}
-		keys = append(keys, out.Data...)
+		keys = append(keys, userKeys...)
 	}
 	return keys, nil
 }

api/chat_test.go

@@ -113,6 +113,52 @@ func TestGetChatPublicKeys(t *testing.T) {
 	assert.Empty(t, requests[0].URL.RawQuery)
 }
 
+func TestGetChatUsersPublicKeysUsesPerUserRoutes(t *testing.T) {
+	var paths []string
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		paths = append(paths, r.URL.Path)
+		w.Header().Set("Content-Type", "application/json")
+		switch r.URL.Path {
+		case "/2/users/7/public_keys":
+			_, _ = w.Write([]byte(`{"data":[{"public_key_version":"1700","public_key":"idpk7","signing_public_key":"sigpk7","identity_public_key_signature":"binding7"}]}`))
+		case "/2/users/8/public_keys":
+			_, _ = w.Write([]byte(`{"data":[{"public_key_version":"1800","public_key":"idpk8","signing_public_key":"sigpk8","identity_public_key_signature":"binding8"}]}`))
+		default:
+			http.Error(w, `{"error":"unexpected route"}`, http.StatusNotFound)
+		}
+	}))
+	defer server.Close()
+	client := chatTestClient(t, server)
+
+	keys, err := GetChatUsersPublicKeys(client, []string{"7", "8"}, RequestOptions{})
+	require.NoError(t, err)
+	require.Len(t, keys, 2)
+	assert.Equal(t, []string{"/2/users/7/public_keys", "/2/users/8/public_keys"}, paths)
+	assert.Equal(t, "7", keys[0].UserID)
+	assert.Equal(t, "1700", keys[0].Version)
+	assert.Equal(t, "8", keys[1].UserID)
+	assert.Equal(t, "1800", keys[1].Version)
+}
+
+func TestGetChatUsersPublicKeysIdentifiesFailedUserAndReturnsNoPartialKeys(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		if r.URL.Path == "/2/users/7/public_keys" {
+			_, _ = w.Write([]byte(`{"data":[{"public_key_version":"1700","public_key":"idpk7","signing_public_key":"sigpk7","identity_public_key_signature":"binding7"}]}`))
+			return
+		}
+		w.WriteHeader(http.StatusForbidden)
+		_, _ = w.Write([]byte(`{"error":"denied"}`))
+	}))
+	defer server.Close()
+	client := chatTestClient(t, server)
+
+	keys, err := GetChatUsersPublicKeys(client, []string{"7", "8"}, RequestOptions{})
+	require.Error(t, err)
+	assert.Nil(t, keys)
+	assert.Contains(t, err.Error(), "user 8")
+}
+
 func TestGetChatEvents(t *testing.T) {
 	var requests []*http.Request
 	var bodies []string