Make Alt and a digit set the send target as /window does (closes #221)

In neoirc-cli, Alt and a digit switched the window but kept the send
target, so typed text went to the window the user had left. The key
now runs /window with that digit through the input handler.

/window 0 now clears the send target. The status window has no target,
but the command used to keep the previous one.

Model: opus-5-5

internal/cli/app.go

@@ -627,6 +627,10 @@ func (a *App) cmdWindow(args string) {
 				nick, buf.Name, "connected",
 			)
 		} else {
+			a.mu.Lock()
+			a.target = ""
+			a.mu.Unlock()
+
 			a.ui.SetStatus(nick, "", "connected")
 		}
 	}

internal/cli/app_internal_test.go

@@ -219,6 +219,63 @@ func TestJoinResponse(t *testing.T) {
 	}
 }
 
+// TestAltDigit checks that Alt and a digit shows that window and
+// makes its channel or user the target, as /window does. Window
+// 0, the status window, leaves no target.
+func TestAltDigit(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name  string
+		digit rune
+		// The buffer shown and the target after the key.
+		wantBuffer string
+		wantTarget string
+	}{
+		{
+			name:       "channel window",
+			digit:      '1',
+			wantBuffer: testChannel,
+			wantTarget: testChannel,
+		},
+		{
+			name:       "status window",
+			digit:      '0',
+			wantBuffer: "(status)",
+			wantTarget: "",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			app := &App{ui: NewUI(), nick: testNick, target: testOtherNick}
+			app.ui.OnInput(app.handleInput)
+			runUI(t, app.ui)
+
+			// Window 1 is the channel. Window 2, the one shown, is
+			// the other user's.
+			app.ui.SwitchToBuffer(testChannel)
+			app.ui.SwitchToBuffer(testOtherNick)
+
+			key := tcell.NewEventKey(tcell.KeyRune, test.digit, tcell.ModAlt)
+			app.ui.app.GetInputCapture()(key)
+
+			var shown string
+
+			app.ui.app.QueueUpdate(func() {
+				shown = app.ui.buffers[app.ui.currentBuffer].Name
+			})
+
+			if shown != test.wantBuffer || app.target != test.wantTarget {
+				t.Fatalf("got buffer %s and target %q, want %s and %q",
+					shown, app.target, test.wantBuffer, test.wantTarget)
+			}
+		})
+	}
+}
+
 // TestOwnEventFromOtherClient checks that a message, notice,
 // join or part that the user's session makes from another
 // client shows as one line in the buffer it belongs to.

internal/cli/ui.go

@@ -240,10 +240,13 @@ func (ui *UI) initKeyCapture() {
 				return event
 			}
 
+			// Alt and a digit runs /window with that digit.
+			// SwitchBuffer alone would leave the target as it was.
 			r := event.Rune()
 			if r >= '0' && r <= '9' {
-				idx := int(r - '0')
-				ui.SwitchBuffer(idx)
+				if ui.onInput != nil {
+					ui.onInput("/window " + string(r))
+				}
 
 				return nil
 			}

internal/config/config.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
+	"math"
 	"os"
 	"strconv"
 	"time"
@@ -31,6 +32,8 @@ Type /help for available commands.`
 const DefaultDBURL = "file:///var/lib/neoirc/state.db" +
 	"?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)"
 
+var errOutOfRange = errors.New("setting out of range")
+
 // Params defines the dependencies for creating a Config.
 type Params struct {
 	fx.In
@@ -67,7 +70,7 @@ type Config struct {
 
 // New creates a new Config by reading from files and environment variables.
 // It returns an error when a number, true/false or duration setting does
-// not parse.
+// not parse or is out of range.
 func New(
 	_ fx.Lifecycle, params Params,
 ) (*Config, error) {
@@ -149,14 +152,16 @@ func New(
 }
 
 // parseSettings reads the number and true/false settings into cfg and
-// checks that each duration setting is a valid Go duration. Its error
-// names each setting whose value does not parse.
+// checks the duration settings. Each number and duration must be above
+// zero. PORT and NEOIRC_HASHCASH_BITS may also be zero: port 0 lets the
+// system pick a port, and 0 bits turns proof of work off. The error
+// names each setting that does not parse or is out of range.
 func parseSettings(cfg *Config) error {
 	return errors.Join(
-		parseInt("PORT", &cfg.Port),
-		parseInt("MAX_MESSAGE_SIZE", &cfg.MaxMessageSize),
-		parseInt("NEOIRC_HASHCASH_BITS", &cfg.HashcashBits),
-		parseInt("LOGIN_RATE_BURST", &cfg.LoginRateBurst),
+		parseInt("PORT", 0, &cfg.Port),
+		parseInt("MAX_MESSAGE_SIZE", 1, &cfg.MaxMessageSize),
+		parseInt("NEOIRC_HASHCASH_BITS", 0, &cfg.HashcashBits),
+		parseInt("LOGIN_RATE_BURST", 1, &cfg.LoginRateBurst),
 		parseFloat("LOGIN_RATE_LIMIT", &cfg.LoginRateLimit),
 		parseBool("DEBUG", &cfg.Debug),
 		parseBool("MAINTENANCE_MODE", &cfg.MaintenanceMode),
@@ -166,25 +171,43 @@ func parseSettings(cfg *Config) error {
 	)
 }
 
-// parseInt sets *value to the setting key read as a whole number.
-func parseInt(key string, value *int) error {
-	parsed, err := strconv.Atoi(viper.GetString(key))
+// parseInt sets *value to the setting key read as a whole number. It
+// returns an error when the value does not parse or is below minimum.
+func parseInt(key string, minimum int, value *int) error {
+	raw := viper.GetString(key)
+
+	parsed, err := strconv.Atoi(raw)
 	if err != nil {
 		return fmt.Errorf("cannot parse %s: %w", key, err)
 	}
 
+	if parsed < minimum {
+		return fmt.Errorf("%w: %s is %s, but must be at least %d",
+			errOutOfRange, key, raw, minimum)
+	}
+
 	*value = parsed
 
 	return nil
 }
 
-// parseFloat sets *value to the setting key read as a decimal number.
+// parseFloat sets *value to the setting key read as a floating-point
+// number. It returns an error when the value does not parse or is not a
+// finite number above zero.
 func parseFloat(key string, value *float64) error {
-	parsed, err := strconv.ParseFloat(viper.GetString(key), 64)
+	raw := viper.GetString(key)
+
+	parsed, err := strconv.ParseFloat(raw, 64)
 	if err != nil {
 		return fmt.Errorf("cannot parse %s: %w", key, err)
 	}
 
+	if math.IsNaN(parsed) || math.IsInf(parsed, 0) || parsed <= 0 {
+		return fmt.Errorf(
+			"%w: %s is %s, but must be a finite number above zero",
+			errOutOfRange, key, raw)
+	}
+
 	*value = parsed
 
 	return nil
@@ -203,12 +226,17 @@ func parseBool(key string, value *bool) error {
 }
 
 // checkDuration returns an error naming the setting key when value is
-// not a valid Go duration.
+// not a Go duration above zero.
 func checkDuration(key, value string) error {
-	_, err := time.ParseDuration(value)
+	duration, err := time.ParseDuration(value)
 	if err != nil {
 		return fmt.Errorf("cannot parse %s: %w", key, err)
 	}
 
+	if duration <= 0 {
+		return fmt.Errorf("%w: %s is %s, but must be above zero",
+			errOutOfRange, key, value)
+	}
+
 	return nil
 }

internal/config/config_test.go

@@ -78,28 +78,30 @@ func TestUnsetSettingsKeepDefaults(t *testing.T) {
 }
 
 func TestValidSettingsAreUsed(t *testing.T) {
-	t.Setenv("PORT", "9000")
-	t.Setenv("MAX_MESSAGE_SIZE", "1024")
+	// Each whole number is the lowest value its setting allows, and 1ns
+	// is the shortest duration allowed.
+	t.Setenv("PORT", "0")
+	t.Setenv("MAX_MESSAGE_SIZE", "1")
 	t.Setenv("NEOIRC_HASHCASH_BITS", "0")
-	t.Setenv("LOGIN_RATE_BURST", "10")
+	t.Setenv("LOGIN_RATE_BURST", "1")
 	t.Setenv("LOGIN_RATE_LIMIT", "0.5")
 	t.Setenv("DEBUG", "true")
 	t.Setenv("MAINTENANCE_MODE", "true")
-	t.Setenv("MESSAGE_MAX_AGE", "24h")
+	t.Setenv("MESSAGE_MAX_AGE", "1ns")
 	t.Setenv("QUEUE_MAX_AGE", "1h30m")
-	t.Setenv("SESSION_IDLE_TIMEOUT", "0")
+	t.Setenv("SESSION_IDLE_TIMEOUT", "45m")
 
 	want := settings{
-		Port:               9000,
-		MaxMessageSize:     1024,
+		Port:               0,
+		MaxMessageSize:     1,
 		HashcashBits:       0,
-		LoginRateBurst:     10,
+		LoginRateBurst:     1,
 		LoginRateLimit:     0.5,
 		Debug:              true,
 		MaintenanceMode:    true,
-		MessageMaxAge:      "24h",
+		MessageMaxAge:      "1ns",
 		QueueMaxAge:        "1h30m",
-		SessionIdleTimeout: "0",
+		SessionIdleTimeout: "45m",
 	}
 
 	got := settingsOf(newConfig(t))
@@ -137,39 +139,45 @@ func settingsOf(cfg *config.Config) settings {
 	}
 }
 
-func TestUnparseableSettingStopsStartup(t *testing.T) {
+func TestBadSettingStopsStartup(t *testing.T) {
+	// For each setting, the first value does not parse and the others
+	// parse but are out of range.
 	tests := []struct {
-		key   string
-		value string
+		key    string
+		values []string
 	}{
-		{key: "PORT", value: "80a"},
-		{key: "MAX_MESSAGE_SIZE", value: "4k"},
-		{key: "NEOIRC_HASHCASH_BITS", value: "twenty"},
-		{key: "LOGIN_RATE_BURST", value: "five"},
-		{key: "LOGIN_RATE_LIMIT", value: "fast"},
-		{key: "DEBUG", value: "yes"},
-		{key: "MAINTENANCE_MODE", value: "on"},
-		{key: "MESSAGE_MAX_AGE", value: "30d"},
-		{key: "QUEUE_MAX_AGE", value: "720"},
-		{key: "SESSION_IDLE_TIMEOUT", value: "a month"},
+		{key: "PORT", values: []string{"80a", "-1"}},
+		{key: "MAX_MESSAGE_SIZE", values: []string{"4k", "0", "-4096"}},
+		{key: "NEOIRC_HASHCASH_BITS", values: []string{"twenty", "-1"}},
+		{key: "LOGIN_RATE_BURST", values: []string{"five", "0", "-5"}},
+		{key: "LOGIN_RATE_LIMIT", values: []string{
+			"fast", "0", "-1", "NaN", "Inf", "-Inf",
+		}},
+		{key: "DEBUG", values: []string{"yes"}},
+		{key: "MAINTENANCE_MODE", values: []string{"on"}},
+		{key: "MESSAGE_MAX_AGE", values: []string{"30d", "0", "-1h"}},
+		{key: "QUEUE_MAX_AGE", values: []string{"720", "0s", "-24h"}},
+		{key: "SESSION_IDLE_TIMEOUT", values: []string{"a month", "0", "-1m"}},
 	}
 
 	for _, test := range tests {
-		t.Run(test.key, func(t *testing.T) {
-			t.Setenv(test.key, test.value)
+		for _, value := range test.values {
+			t.Run(test.key+"="+value, func(t *testing.T) {
+				t.Setenv(test.key, value)
 
-			_, err := loadConfig(t)
-			if err == nil {
-				t.Fatalf("%s=%q: got no error", test.key, test.value)
-			}
+				_, err := loadConfig(t)
+				if err == nil {
+					t.Fatalf("%s=%q: got no error", test.key, value)
+				}
 
-			msg := err.Error()
-			if !strings.Contains(msg, test.key) ||
-				!strings.Contains(msg, test.value) {
-				t.Errorf("error %q does not name %s and %q",
-					msg, test.key, test.value)
-			}
-		})
+				msg := err.Error()
+				if !strings.Contains(msg, test.key) ||
+					!strings.Contains(msg, value) {
+					t.Errorf("error %q does not name %s and %q",
+						msg, test.key, value)
+				}
+			})
+		}
 	}
 }