fix(slack): allow disabling ack reactions

Author: onutc

integrations/slack-gateway/config.go

@@ -53,7 +53,7 @@ func loadConfig() (config, error) {
 		OAuthStateSecret:           strings.TrimSpace(os.Getenv("SPRITZ_SLACK_OAUTH_STATE_SECRET")),
 		SlackAPIBaseURL:            strings.TrimRight(envOrDefault("SPRITZ_SLACK_API_BASE_URL", "https://slack.com/api"), "/"),
 		SlackBotScopes:             splitCSV(envOrDefault("SPRITZ_SLACK_BOT_SCOPES", "app_mentions:read,channels:history,chat:write,im:history,mpim:history,reactions:write")),
-		AckReaction:                normalizeSlackReactionName(envOrDefault("SPRITZ_SLACK_ACK_REACTION", "eyes")),
+		AckReaction:                normalizeSlackReactionName(envOrDefaultIfUnset("SPRITZ_SLACK_ACK_REACTION", "eyes")),
 		RemoveAckAfterReply:        parseBoolEnv("SPRITZ_SLACK_REMOVE_ACK_AFTER_REPLY", true),
 		PresetID:                   strings.TrimSpace(envOrDefault("SPRITZ_SLACK_PRESET_ID", defaultSlackPresetID)),
 		BackendBaseURL:             strings.TrimRight(strings.TrimSpace(os.Getenv("SPRITZ_SLACK_BACKEND_BASE_URL")), "/"),
@@ -174,6 +174,14 @@ func envOrDefault(key, fallback string) string {
 	return fallback
 }
 
+func envOrDefaultIfUnset(key, fallback string) string {
+	value, ok := os.LookupEnv(key)
+	if !ok {
+		return fallback
+	}
+	return strings.TrimSpace(value)
+}
+
 func parseDurationEnv(key string, fallback time.Duration) time.Duration {
 	raw := strings.TrimSpace(os.Getenv(key))
 	if raw == "" {

integrations/slack-gateway/gateway_test.go

@@ -8180,6 +8180,28 @@ func TestLoadConfigIncludesMPIMHistoryByDefault(t *testing.T) {
 	}
 }
 
+func TestLoadConfigAllowsDisablingAckReaction(t *testing.T) {
+	t.Setenv("SPRITZ_SLACK_GATEWAY_PUBLIC_URL", "https://gateway.example.test")
+	t.Setenv("SPRITZ_SLACK_CLIENT_ID", "client-id")
+	t.Setenv("SPRITZ_SLACK_CLIENT_SECRET", "client-secret")
+	t.Setenv("SPRITZ_SLACK_SIGNING_SECRET", "signing-secret")
+	t.Setenv("SPRITZ_SLACK_OAUTH_STATE_SECRET", "oauth-state-secret")
+	t.Setenv("SPRITZ_SLACK_BACKEND_BASE_URL", "https://backend.example.test")
+	t.Setenv("SPRITZ_SLACK_BACKEND_INTERNAL_TOKEN", "backend-internal-token")
+	t.Setenv("SPRITZ_SLACK_SPRITZ_BASE_URL", "https://spritz.example.test")
+	t.Setenv("SPRITZ_SLACK_SPRITZ_SERVICE_TOKEN", "spritz-service-token")
+	t.Setenv("SPRITZ_SLACK_PRINCIPAL_ID", "shared-slack-gateway")
+	t.Setenv("SPRITZ_SLACK_ACK_REACTION", "")
+
+	cfg, err := loadConfig()
+	if err != nil {
+		t.Fatalf("loadConfig failed: %v", err)
+	}
+	if cfg.AckReaction != "" {
+		t.Fatalf("expected empty ack reaction to disable Slack ack reactions, got %q", cfg.AckReaction)
+	}
+}
+
 func TestLoadConfigDefaultsBackendFastAPIBaseURLToBackendBaseURL(t *testing.T) {
 	t.Setenv("SPRITZ_SLACK_GATEWAY_PUBLIC_URL", "https://gateway.example.test")
 	t.Setenv("SPRITZ_SLACK_CLIENT_ID", "client-id")