Validate poll interval is positive to prevent ticker panic

cmd/ratelord-d/config.go

@@ -44,6 +44,9 @@ func LoadConfig(args []string) (Config, error) {
 		if err != nil {
 			return Config{}, fmt.Errorf("invalid RATELORD_POLL_INTERVAL: %w", err)
 		}
+		if parsed <= 0 {
+			return Config{}, errors.New("RATELORD_POLL_INTERVAL must be positive")
+		}
 		pollInterval = parsed
 	}
 	webAssetsMode := envOrDefault("RATELORD_WEB_ASSETS_MODE", defaultWebAssetsMode)
@@ -71,6 +74,9 @@ func LoadConfig(args []string) (Config, error) {
 	if err != nil {
 		return Config{}, fmt.Errorf("invalid poll interval: %w", err)
 	}
+	if pollIntervalParsed <= 0 {
+		return Config{}, errors.New("poll interval must be positive")
+	}
 
 	resolvedDBPath := resolvePath(*flagDB, cwd)
 	resolvedPolicyPath := resolvePath(*flagPolicy, cwd)

cmd/ratelord-d/config_test.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestLoadConfig_PollIntervalValidation(t *testing.T) {
+	tests := []struct {
+		name        string
+		args        []string
+		envVars     map[string]string
+		expectError bool
+		errorSubstr string
+	}{
+		{
+			name:        "valid poll interval from flag",
+			args:        []string{"-poll-interval", "5s"},
+			expectError: false,
+		},
+		{
+			name:        "zero poll interval from flag",
+			args:        []string{"-poll-interval", "0s"},
+			expectError: true,
+			errorSubstr: "poll interval must be positive",
+		},
+		{
+			name:        "negative poll interval from flag",
+			args:        []string{"-poll-interval", "-5s"},
+			expectError: true,
+			errorSubstr: "poll interval must be positive",
+		},
+		{
+			name:        "valid poll interval from env",
+			envVars:     map[string]string{"RATELORD_POLL_INTERVAL": "5s"},
+			expectError: false,
+		},
+		{
+			name:        "zero poll interval from env",
+			envVars:     map[string]string{"RATELORD_POLL_INTERVAL": "0s"},
+			expectError: true,
+			errorSubstr: "RATELORD_POLL_INTERVAL must be positive",
+		},
+		{
+			name:        "negative poll interval from env",
+			envVars:     map[string]string{"RATELORD_POLL_INTERVAL": "-5s"},
+			expectError: true,
+			errorSubstr: "RATELORD_POLL_INTERVAL must be positive",
+		},
+		{
+			name:        "invalid poll interval format from flag",
+			args:        []string{"-poll-interval", "invalid"},
+			expectError: true,
+			errorSubstr: "invalid poll interval",
+		},
+		{
+			name:        "invalid poll interval format from env",
+			envVars:     map[string]string{"RATELORD_POLL_INTERVAL": "invalid"},
+			expectError: true,
+			errorSubstr: "invalid RATELORD_POLL_INTERVAL",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Set up environment variables
+			for k, v := range tt.envVars {
+				os.Setenv(k, v)
+				defer os.Unsetenv(k)
+			}
+
+			cfg, err := LoadConfig(tt.args)
+
+			if tt.expectError {
+				if err == nil {
+					t.Errorf("expected error containing %q, got nil", tt.errorSubstr)
+				} else if !strings.Contains(err.Error(), tt.errorSubstr) {
+					t.Errorf("expected error containing %q, got %q", tt.errorSubstr, err.Error())
+				}
+			} else {
+				if err != nil {
+					t.Errorf("unexpected error: %v", err)
+				} else if cfg.PollInterval <= 0 {
+					t.Errorf("expected positive poll interval, got %v", cfg.PollInterval)
+				}
+			}
+		})
+	}
+}
+
+func TestLoadConfig_DefaultPollInterval(t *testing.T) {
+	cfg, err := LoadConfig([]string{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if cfg.PollInterval != 10*time.Second {
+		t.Errorf("expected default poll interval of 10s, got %v", cfg.PollInterval)
+	}
+}