fix: computeTrend division by zero, add tests for trend and currency parsing, add username to settings

internal/bot/burnout.go

@@ -212,11 +212,37 @@ func computeTrend(store *db.Store, userID int64, today string, loc *time.Locatio
 	recentAvg /= 3.0
 	olderAvg /= 3.0
 
+	if olderAvg < 1 {
+		if recentAvg > 0 {
+			return 15, "new"
+		}
+		return 5, "stable"
+	}
+
+	changePct := math.Round((recentAvg - olderAvg) / olderAvg * 100)
 	if recentAvg > olderAvg*1.2 {
-		return 15, fmt.Sprintf("+%.0f%%", math.Round((recentAvg-olderAvg)/math.Max(olderAvg, 1)*100))
+		return 15, fmt.Sprintf("+%.0f%%", changePct)
 	}
 	if olderAvg > recentAvg*1.2 {
-		return 0, fmt.Sprintf("-%.0f%%", math.Round((olderAvg-recentAvg)/math.Max(olderAvg, 1)*100))
+		return 0, fmt.Sprintf("%.0f%%", changePct)
+	}
+	return 5, "stable"
+}
+
+// computeTrendFromAvgs is a pure version of the trend computation for testing.
+func computeTrendFromAvgs(recentAvg, olderAvg float64) (pts int, direction string) {
+	if olderAvg < 1 {
+		if recentAvg > 0 {
+			return 15, "new"
+		}
+		return 5, "stable"
+	}
+	changePct := math.Round((recentAvg - olderAvg) / olderAvg * 100)
+	if recentAvg > olderAvg*1.2 {
+		return 15, fmt.Sprintf("+%.0f%%", changePct)
+	}
+	if olderAvg > recentAvg*1.2 {
+		return 0, fmt.Sprintf("%.0f%%", changePct)
 	}
 	return 5, "stable"
 }

internal/bot/rpg_test.go

@@ -1,6 +1,7 @@
 package bot
 
 import (
+	"strings"
 	"testing"
 )
 
@@ -170,4 +171,57 @@ func TestSanitizeDisplayName(t *testing.T) {
 	if got := SanitizeDisplayName("Ali\x00ce"); got != "Alice" {
 		t.Errorf("SanitizeDisplayName control: got %q", got)
 	}
+	if got := SanitizeDisplayName(""); got != "" {
+		t.Errorf("SanitizeDisplayName empty: got %q", got)
+	}
+}
+
+func TestParseCurrencyInput(t *testing.T) {
+	cases := []struct {
+		input string
+		want  string
+		ok    bool
+	}{
+		{"$ USD", "$ USD", true},
+		{"T Toman", "T Toman", true},
+		{"IRR Rial", "IRR Rial", true},
+		{"€ EUR", "€ EUR", true},
+		{"", "", false},
+		{"$", "", false},
+		{"   ", "", false},
+		{"$$$ TooLongCode", "", false},
+	}
+	for _, c := range cases {
+		got, errMsg := parseCurrencyInput(c.input)
+		if c.ok && (got != c.want || errMsg != "") {
+			t.Errorf("parseCurrencyInput(%q) = (%q, %q), want (%q, \"\")", c.input, got, errMsg, c.want)
+		}
+		if !c.ok && errMsg == "" {
+			t.Errorf("parseCurrencyInput(%q) = (%q, \"\"), want error", c.input, got)
+		}
+	}
+}
+
+func TestComputeTrendFromAvgs(t *testing.T) {
+	cases := []struct {
+		recent, older float64
+		wantPts       int
+		wantDirSub    string
+	}{
+		{0, 0, 5, "stable"},
+		{100, 0, 15, "new"},
+		{0, 100, 0, "-100"},
+		{121, 100, 15, "+21"},
+		{100, 100, 5, "stable"},
+		{100, 130, 0, "-23"},
+	}
+	for _, c := range cases {
+		pts, dir := computeTrendFromAvgs(c.recent, c.older)
+		if pts != c.wantPts {
+			t.Errorf("computeTrendFromAvgs(%.0f, %.0f) pts = %d, want %d", c.recent, c.older, pts, c.wantPts)
+		}
+		if !strings.Contains(dir, c.wantDirSub) {
+			t.Errorf("computeTrendFromAvgs(%.0f, %.0f) dir = %q, want containing %q", c.recent, c.older, dir, c.wantDirSub)
+		}
+	}
 }

internal/bot/salary.go

@@ -6,6 +6,7 @@ import (
 	"math"
 	"strings"
 	"time"
+	"unicode"
 
 	"github.com/go-telegram/bot/models"
 
@@ -179,6 +180,20 @@ func (h *Handler) handleSetRateMsg(ctx context.Context, msg *models.Message) {
 	h.sendText(ctx, msg.Chat.ID, fmt.Sprintf("Hourly rate set to %s%.2f", currencySymbol(st.Currency), st.HourlyRate))
 }
 
+// parseCurrencyInput validates and normalizes currency input (symbol + code).
+func parseCurrencyInput(s string) (string, string) {
+	parts := strings.Fields(s)
+	if len(parts) < 2 {
+		return "", "Please provide both symbol and code.\nUsage: /setcurrency <symbol> <code>\nExamples:\n/setcurrency $ USD\n/setcurrency T Toman\n/setcurrency IRR Rial"
+	}
+	for _, p := range parts[:2] {
+		if len(p) > 10 || strings.ContainsFunc(p, unicode.IsControl) {
+			return "", "Invalid currency. Use short printable strings like $ USD, T Toman, IRR Rial."
+		}
+	}
+	return parts[0] + " " + parts[1], ""
+}
+
 // handleSetCurrencyMsg handles /setcurrency <symbol> <code>.
 func (h *Handler) handleSetCurrencyMsg(ctx context.Context, msg *models.Message) {
 	args := strings.TrimSpace(strings.TrimPrefix(msg.Text, "/setcurrency"))
@@ -192,20 +207,11 @@ func (h *Handler) handleSetCurrencyMsg(ctx context.Context, msg *models.Message)
 		h.sendText(ctx, msg.Chat.ID, fmt.Sprintf("Current currency: %s\nUsage: /setcurrency <symbol> <code>\nExamples:\n/setcurrency $ USD\n/setcurrency T Toman\n/setcurrency IRR Rial", st.Currency))
 		return
 	}
-	parts := strings.Fields(args)
-	if len(parts) < 2 {
-		h.sendText(ctx, msg.Chat.ID, "Please provide both symbol and code.\nUsage: /setcurrency <symbol> <code>\nExamples:\n/setcurrency $ USD\n/setcurrency T Toman\n/setcurrency IRR Rial")
+	currency, errMsg := parseCurrencyInput(args)
+	if errMsg != "" {
+		h.sendText(ctx, msg.Chat.ID, errMsg)
 		return
 	}
-	if len(parts[0]) > 10 || strings.ContainsFunc(parts[0], func(r rune) bool { return r < 32 || r > 126 }) {
-		h.sendText(ctx, msg.Chat.ID, "Invalid currency symbol. Use a short printable string like $, €, £.")
-		return
-	}
-	if len(parts[1]) > 10 || strings.ContainsFunc(parts[1], func(r rune) bool { return r < 32 || r > 126 }) {
-		h.sendText(ctx, msg.Chat.ID, "Invalid currency code.")
-		return
-	}
-	currency := parts[0] + " " + parts[1]
 	user, err := h.getOrCreateUser(msg.Chat.ID)
 	if err != nil {
 		h.sendText(ctx, msg.Chat.ID, "Error loading profile")

internal/bot/settings.go

@@ -192,6 +192,9 @@ func (h *Handler) buildSettingsKeyboard(user *db.User, st *db.UserSettings, brea
 		leagueStatus = "on"
 	}
 	rows := [][]models.InlineKeyboardButton{
+		{
+			{Text: fmt.Sprintf("Username: %s", user.Username), CallbackData: "username"},
+		},
 		{
 			{Text: fmt.Sprintf("Timezone: %s", user.Timezone), CallbackData: "timezone"},
 			{Text: fmt.Sprintf("Calendar: %s", user.Calendar), CallbackData: "caltype"},
@@ -208,12 +211,9 @@ func (h *Handler) buildSettingsKeyboard(user *db.User, st *db.UserSettings, brea
 			{Text: fmt.Sprintf("RPG: %s", rpgStatus), CallbackData: "rpgtoggle"},
 			{Text: fmt.Sprintf("League: %s", leagueStatus), CallbackData: "leaguetoggle"},
 		},
-		{
-			{Text: fmt.Sprintf("Username: %s", user.Username), CallbackData: "username"},
-			{Text: fmt.Sprintf("Currency: %s", st.Currency), CallbackData: "currency"},
-		},
 		{
 			{Text: fmt.Sprintf("Rate: %.2f", st.HourlyRate), CallbackData: "setrate"},
+			{Text: fmt.Sprintf("Currency: %s", st.Currency), CallbackData: "currency"},
 		},
 		{{Text: "Back to Menu", CallbackData: "back_menu"}},
 	}